DEVELOPMENT OF SIMPLE AIDS FOR TEACHING SCIENCE
IN BASIC SCHOOLS
ERNWACA - Ghana
Wisdom Harrison Kofi Hordzi [email protected]
Julius Kofi Agbeko
Advisor:
Dr. B.A. Mensah
February 2003 Accra, Ghana
ROCARE / ERNWACA • Tel: (223) 221 16 12 / 674 83 84, Fax: (223) 221 21 15 • BP E 1854, Bamako, MALI • in [email protected] Bénin • Burkina Faso • Cameroun • Côte d’Ivoire • Gambia •Ghana • Guinée• Mali • Nigeria • Sénégal • Sierra Leon • Togo
www.rocare.org
Réseau Ouest et Centre Africain de Recherche en Education
Educational Research Network for West And Central Africa
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 2
Abstract Why do so many students in Ghana not develop an interest in science topics such as biology, chemistry and physics? The subjects teach practical and research skills necessary to a student’s educational development from their early school days and throughout their lives. This report looks at the specific problems associated with a lack of teaching aids and methods of teaching science classes, and aims to identify inexpensive materials and interactive models that could be adapted to improve the interest level of students in science programs. New materials were suggested for use in biological classes (e.g. circulatory system, cells and nerve cells), chemistry classes (e.g. atoms, molecules and compounds; colour separation) and physics classes (the solar system). The models were piloted at many schools, one class was taught using the prepared (test) model and another class was not. Students were marked at the end of each class and teachers answered questions posed by the research team. The questionnaire asked if the models were easy to work with, if they made teaching easier, and if the teachers would recommend their use in other schools and countries. This project achieved its objective of stimulating the interest of students in science and to enhance their understanding and performance in the topics. The students’ marks were generally higher in the test model group and their interest was high to participate in the classes. The models were easy to use for 95% of both the more and less experienced teachers. Approximately 97% of the teachers found that teaching was made easier and more successful after applying the test program and 94% would recommend their use more widely. Indications are good that these methods can be used for multiple grades of teaching. The methods need refining, and the process began through recommendations by the teachers after the first round of experimentation. For example, they suggested using dry cells instead of electricity for the solar system, as many schools in Africa are in rural areas without electricity. Generally, the teachers felt unprepared to initiate models like this one because they are unfamiliar with the locally available materials that could be used as substitutes for the more expensive equipment currently used in school laboratories. The level of science taught in the teacher training college in Ghana is about equivalent to the level taught in years preceding college entry, so there is potential room in the post-secondary program to research alternative teaching materials. Both the young adults studying to become teachers and the children studying sciences in earlier grades would benefit. A similar, larger project to develop locally prepared science teaching aids could be funded by educational administrators and supplemented through solicitation from relevant donors. For example, local toy manufacturing companies could mass-produce the relevant materials at moderate prices for schools in their areas. The combination of training, method development, and production of materials drawn from the recommendations in this report present a feasible and cost-efficient model for improving student interest in studying science.
“The models were great innovations, which stimulated interest of students in lessons and made the lessons lively (and) very interesting. ”
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 3
Research financed by the
EDUCATIONAL RESEARCH NETWORK
FOR WEST AND CENTRAL AFRICA
www.ernwaca.org
in the context of its Small Grants Program for Education Research,
Year 2002 Competition,
with the support of the
International Development Research Centre (IDRC)
and the
SARA Program of the
Academy for Educational Development (AED)
and USAID
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 4
T A B L E O F C O N T E N T S Page
1. OVERVIEW .................................................................................................................................. 6 1.1 Introduction 1.2 Brief reference to the Literature 1.3 Aims and objectives 1.4 Questions and hypotheses
2. METHODOLOGY ....................................................................................................................... 8 2.1 Preparation of the models 2.2 Trials and dissemination
3. RESULTS ...................................................................................................................................... 11 3.1 Experimental results 3.2 Survey results from questionnaires
4. DISCUSSION OF RESULTS ...................................................................................................... 15
5. CONCLUSIONS ........................................................................................................................... 19 REFERENCES ............................................................................................................................. 21 APPENDIXES
1. Preparation of the Models .................................................................................................... 22 a. Cells b. Atoms, molecules and compounds c. Solar system d. Colour separation (chromatography) e. Circulatory system f. Nerve cells g. Acid-based indicators
2. Assessment of the simple science teaching aids ...................................................................... 31 3. Marks obtained by students, control group (w/o models) vs. test group (with
models) ................................................................................................................................ 33 4. Academic level in science, levels being taught, and teaching experience of
respondents ......................................................................................................................... 37 TABLES
1. Reactions of NaOH, HCl, plantain peel ash filtrate and cocoa pod ash filtrate with the edible extracts ................................................................................................................ 11
2. Percentage of students who obtained marks above 40%(pass mark) when the models were used (test experiment) and when not used (control) ........................................... 13
3. Categories of questions and trend of responses obtained from teachers .................................. 14
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 5
OBJECTIVES OF THE STUDY As a way of contributing towards demystifying science and making it as simple as possible to students
of basic schools in Ghana and for that matter West and Central African countries, this project aimed at
using local or inexpensive materials in developing science teaching aids that can be used in teaching
some topics in basic schools.
Thus, the objectives are:
? ? To develop models for teaching some biological topics (e.g. circulatory system, cells and nerve
cells), some chemistry topics (e.g. atoms, molecules and compounds; colour separation), and a
physics topic (the solar system).
? ? To pilot the use of the teaching aids produced in some junior secondary schools in Ghana to find out
how they could contribute to the understanding of lessons by students.
? ? To sample views of some teachers who would be introduced to the models to find out the
acceptability of the models as science teaching aids.
SUMMARY OF MAJOR FINDINGS ? ? From the results of chromatography (colour separation), both water and alcohol caused colour
separation of BIC black ink along chalk stick, cassava chip and yam chip. However, the best result
was obtained when chalk stick was used and alcohol as mobile phase also provided better results
than water.
? ? Along syringe column, components of BIC black pen ink separated when starch, maize powder or
chalk powder was the stationary phase and water was the mobile phase.
? ? Tomato extract changed NaOH solution orange – green, but showed no colour change in HCl,
limejuice, cocoa pod ash filtrate or plantain peel ash filtrate.
? ? The orange – green mixture of NaOH and tomato extract changed colourless when HCI was added
drop wise.
? ? Onion extract changed to pink colour in HCI and limejuice but green in NaOH, and the ash filtrates.
The mixture of onion extract and NaOH or ash filtrates changed colourless when HCI or limejuice
was added drop wise.
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 6
? ? Ginger extract showed no colour change in HCl or limejuice but pink colour in NaOH or the ash
filtrates. The mixture of ginger and NaOH or ash filtrates changed colourless when HCl or limejuice
was added drop wise.
? ? It was only the onion extract indicator paper that showed colour change with NaOH and the two ash
filtrates.
? ? Marks obtained from three schools, which tried the models showed that marks of students who were
taught when the teaching aids (models) were used, were generally higher than for students who did
not benefit from the use of the models.
? ? Majority of the respondents (at least 88.71%) agreed that the models were easy to use and
recommended their use in other schools in Ghana as well as other countries.
? ? Many respondents (69%) said that students’ interest in the lessons was high when the models were
used and they generally made lessons lively whilst others described them as great innovation.
? ? Some other respondents (52.%) said that the ideas were quite good but need to be refined a bit.
1. OVERVIEW
1.1. INTRODUCTION Many students in Ghana do not take much interest in learning science largely due to the way the subject
is taught. Many teachers adopt the lecture method of teaching science even at the basic level of learning
where a practical approach would best whip up the interest of students in the subject. Thus, instead of
making science fun and more interesting, it has rather become a scarecrow. Though part of the blame
can be put at the doorsteps of the teachers of the subject, it can also be attributed to lack of teaching aids
in the basic schools. This is because the country depends to a large extent on imported equipment for
teaching science. These are very expensive and considering the economic status of the country, it has
not been easy importing them. Meanwhile, it is necessary to imbue children with practical and research
skills from early school days so that they can develop interest in research and discovering new things in
the future.
Even in the absence of imported teaching equipment or aids, students can still be imbued with practical
and research skills by using local materials to improvise such teaching aids. What the teacher needs is
to understand his subject matter well, translate it into physical materials that can be used in teaching the
lesson and involve the students in the preparation of such materials. However, the Ghanaian school
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 7
science teachers rarely do this because they are not familiar with the available materials in the
environment that can be used, probably because of the way the teachers themselves were taught when
they were students.
These problems enumerated are not peculiar to Ghana, but most of the countries in the West and Central
African sub-regions are also affected one way or the other.
1.2 LITERATURE REVIEW Mass (1984) developed molecular models for teaching chemistry from easily available materials like
corrugated cardboard obtained from empty boxes in India. Shebalkar (1988) also in India used low cost
materials such as Perspex sheets, neoprene sheets and chloroform in making simple and inexpensive
glove box for teaching. Samanta and Mukherjee (1991) managed to use extracts from flowers in the
environment as acid – base indicators. According to Bhandula et al. (1999) and Sharma (2001),
preparation of improvised apparatus and teaching aids do not involve specialized skills and can be made
by pupil/students, teachers or members of the community. According to them, such teaching aids
stimulate thinking, reaction, discussion, experimentation and further studies. These help the child to
develop scientific skills, and basic principles, hand and head coordination, scientific thinking, self-
criticism, self- sufficiency, confidence to face problems, joy of creation and utilization of leisure.
1.3 AIMS AND OBJECTIVES The most readily available remedy to the problem of lack of science teaching equipment in the basic
schools in Ghana is the use of science equipment that is produced locally from indigenous materials.
Thus, there is the need for models and improvised or simulated apparatus made from materials that are
common in our environment or easily available in stores at very moderate prices. These are also
materials that students can easily identify with. Hence, this project aims at using local or inexpensive
materials in developing, science teaching aids such as models and simple apparatus that can be used in
teaching some science topics at the basic level of education in Ghana and the subregions.
The main objectives of the project are as follows:
i. Identify easily available and inexpensive materials in the environment and use them in
developing models for teaching some biological topics (e.g. Circulatory system, nervous
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 8
systems, and cells), some chemistry topics (e.g. atoms, molecules and compounds, colour
separation), and a physics topic (the solar system).
ii. Pilot the use of the teaching aids produced in some junior secondary schools in Ghana to
find out how effectively the models can contribute to the understanding of lessons by
students
iii. Sample the views of some teachers who would be introduced to the models to find out the
acceptability of the models.
1.4 QUESTIONS ANDHYPOTHESES It was believed that the models developed would help to simplify related topics for students. This way,
the understanding of the topics by students would be enhanced. It was also believed that the models
prepared would be acceptable to teachers in Ghana and adopted by teachers in other African countries.
The following questions were asked teachers who were introduced to the models to determine their
views about them:
i. Are the models easy to work with?
ii. Did the use of the models make teaching of the topics easier?
iii. Would you recommend the use of the models in other countries?
iv. What would be your rating of the models?
v. Which of the models need to be improved and what modification do you suggest?
2. METHODOLOGY
2.1 PREPARATION OF THE MODELS
(a) Cells
Model of plant and animal cells were made from cardboard/plywood, thread, A4 paper, small
gravels/pieces of cardboard, paint, and clothing material (See Appendix 1).
(b) Atoms, molecules and compounds
Models for teaching the atom, molecules and compounds were prepared by using: cardboard/plywood,
thread/twine or rope, cane pieces, paints, and hook loop (sticker) (Appendix 1).
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 9
(c) Solar system
The solar system was made using plastic balls of different sizes, nylon rope, glue, plywood, paints,
cardboard, electric bulb and wire, and a stand (Appendix 1).
(d) Colour separation (Chromatography)
Chromatography was demonstrated by using chalk stick, cassava chip, yam chip, chalk powder, maize
powder and starch powder as stationary phase, water and alcohol as mobile phase and syringe as the
column. Black ink was used as the mixture (Appendix 1).
(e) Circulatory System
A model of the circulatory system was made by using foam mattress, water hose, plastic bottles, paints
rubber bands and glue (Appendix 1).
(f) Nerve Cells
Nerve cells for demonstrating the transmission of nerve impulses was prepared by using wooden board,
wire, A4 paper, old rubber shoe, plastic plates, glue and nails (Appendix 1).
(g) Acid-based Indicators
Extracts of edible materials such as tomatoes, ginger and onion were used as acid-base indicators in
dilute hydrochloric acid (HCl), sodium hydroxide (NaOH), lime juice, cocoa pod ash filtrate and
plantain peel ash filtrate. The paper indicators as well as the extracts were used in the various solutions
to find out if they can bring about colour change (Appendix 1).
2.2 TRIALS AND DISSEMINATION
(a) Trials
The models produced were given out to science teachers in three junior Secondary schools to use in
teaching the necessary topics. The teachers were given common questions on each topic to examine the
students on how the models enhanced their understanding of the topics. In each form, two classes were
randomly selected. One class was taught without using the model (control) whilst the other class was
taught using the prepared model (test experiment). The same number of minutes was used in teaching
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 10
the topics in the two classes. After the lessons, the same questions were administered to the two classes
and the scripts marked by the teachers using the same marking scheme and the marks recorded. To be
certain that the teachers actually marked the scripts correctly, one fifth (1/5) of the number of scripts in
each class was randomly selected by the researchers and crosschecked with the marking scheme. From
each class, thirty (30) marks were selected randomly for analysis. This was done by giving numbers to
each student such as 1,2,3,4,5… to cover the number of students in each class. Each number was
written on a piece of paper and folded. All the folded pieces of paper bearing the numbers were placed
in a plastic bowl, mixed up and thirty selected without replacement with intermittent mixing. The pieces
of paper were then opened up and the corresponding mark recorded. The frequency of marks and their
percentage frequencies within certain range were calculated.
The percentage frequencies were used to draw bar graphs against the various ranges for comparison. In
all, marks for 4 models, namely, cells; atoms, molecules and compounds; the solar system and
chromatogram (Chromatography) were collected. Marks were not collected for the other models due to
time constraints.
(b) Dissemination
Over 90 science teachers, majority of which are in the basic level, were introduced to the models
prepared. Sixty-five (65) questionnaires were given out to some of these teachers to solicit their
opinions on the models made. The teachers who were given the questionnaires were selected randomly
by balloting. Those who picked yes were given the questionnaires to respond to. The questionnaire
(Appendix 2) contained eleven (11) simple closed and open questions. The responses of respondents
were collated and analyzed.
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 11
3. RESULTS
3.1 EXPERIMENTAL RESULTS
(a) Acid-based indicators
The colours of the extracts are as follows: tomato Colourless, Onion light green; ginger
deep brown; cocoa pod ash filtrate colourless with suspended black particles; plantain peel ash
filtrate blackish colour; and lime juice pale colour. The results of the reactions of HCl
solution, NaOH solution, cocoa pod ash filtrate and plantain peel ash filtrate are presented in Table 1.
Table 1: Reactions of NaOH, HCl, plantain peel ash filtrate and cocoa pod ash filtrate with the edible extracts
Colour changes after addition of the extracts Tomato Onion Ginger
Reagent / filtrate +Tomato +NaOH +Onion +NaOH +Ginger +NaOH
HCl No Change No Change Pink Orange Green
No Change Light green
Lime juice No change Light green Pink Green No change Orange green +Tomato +HCl + Onion +HCl +Ginger +HCl
NaOH Orange green Colourless Orange green Colourless Pink Colourless +Tomato +lime juice + Onion + Lime juice +Ginger +Lime juice NaOH Orange green Colourless Orange-
green Colourless Pink Colourless
+Tomato +HCl +Onion +HCl +Ginger +Lime juice Cocoa Ash filtrate No Change No change Green Colourless Pink Colourless
+Tomato +Lime juice + Onion +Lime juice Pink Colourless Cocoa Ash filtrate No Change No Change Green Colourless Pink Colourless
+Tomato +HCl +Onion +HCl +Ginger +HCl Plantain peel ash filtrate
No Change No Change Light green Colourless Pink Colourless
+Tomato +lime juice +lime juice +lime juice +lime juice +lime juice Plantain peel ash filtrate No Change No Change Light green Colourless Pink Colourless
When the indicator papers prepared were used in place of the liquid, tomatoes and ginger did not show
any colour change with any of the reagents/filtrates. Onion indicator paper changed green NaOH and
the two ash filtrates. However, it did not show any colour change with HCl or line juice.
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 12
(b) Colour separation (Chromatography)
(i) Using chalk stick, cassava and yam chips
When black ink from BIC pen was applied to the stick of chalk, cassava and yam chips and placed in
water, the following results were obtained: For chalk stick yellow colour moved out first followed by
red (deep pink) then blue - black colour. When ink with trademark name KOFA was used red colour
moved first fellow by blue – black colour. For cassava and yam chip, KOFA ink could not separate in
to any visible components but black ink from BIC pen separated with red colour first fellow by blue-
black colour and the separation was very slow. However, when alcohol was used in place of water,
black ink from BIC pen separated with more distinct colour bands and the separation was very fast. It
was however the best for chalk stick. In alcohol, KOFA ink did not show any distinct colour separation.
(ii) Using columns
When black ink from BIC pen was used with water as the mobile phase.
?? For maize powder as stationary phase, orange colour separates first, followed by red, then black. It
was the same case for chalk powder as stationary phase. In both cases separation delayed.
?? Separation through starch powder started earlier and the order of separation was yellow, red, blue
then green.
?? When KOFA type of ink was used as the mixture and water as mobile phase the order for colour
separation for chalk, maize and starch was: red, and then blue-black. When alcohol was used as
mobile phase with maize powder and starch as stationary phases yellow separated first followed by
red then blue-black. For chalk powder as stationary phase and alcohol as mobile phase the order
was: yellow, light green, red then blue-black.
?? When KOFA type of ink was used there was no distinct colour separation for starch and chalk when
alcohol was used. However, for maize powder separation was red, followed by blue-black co–lour.
?? For either – water or alcohol as mobile phase – the red colour was very distinct when maize powder
was used as stationary phase.
MARKS
(a) Cells
The raw percentage marks obtained by students when the model cells were used are presented in
Appendix 3. In school A only 26.67% of the students in the class where the model was not used
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 13
(control) had marks above 40% (pass mark) where as 86.66% for the class in which the models
were used (test experiment) obtained marks above 40%. In school B, 70% of the class for control
obtained above 40% whilst 100% for test experiment had above 40%.
In school C, 66.67% of students for control experiment obtained above 40% whilst 96.67% of the
student population for test experiment obtained marks above 40% (Table 2).
Table 2: Percentage of students who obtained marks above 40% (pass mark) when the models were used (test experiment) and when not used (control)
% of students for the various models
Cells Atoms, molecules and compounds
Solar System Colour separation (Chromatography) SC
HO
OL
Control Test Control Test Control Test Control Test A 26.67 86.66 19.99 90 60 93.33 - - B 70 100 56.67 100 50 100 90 96.67 C 66.67 96.67 86.68 100 96.66 100 86.67 100 (b) Atoms, molecules and compounds
The raw percentage marks obtained by students when the models for atoms, molecules and
compounds were used are presented in Appendix 3. In school A, only 19.99% of students for the
control experiment had marks above 40% whilst 90% of students for test experiment obtained
above 40%. In school B it is 56.67% for control and 100% for test experiment. In school C it is
86.68% for control and 100% for test experiment (Table 2, figure 2).
(c) Solar System
The raw percentage marks obtained by students when the model solar system was used are
presented in Appendix 3. The percentage number of students who obtained marks above 40% in
the various schools is: in school A, 60% for control and 93.33% for test experiment. In school B,
50% for control and 100% for test experiment. In school C, 96.66% for control and 100% for test
experiment (Table2, figure 3).
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 14
(d) Colour separation (Chromatography)
The raw marks obtained by students when the chromatogram was used are presented in Appendix 3.
The percentages of students who obtained marks above 40% when the chromatogram was used are
as follows: In school B, 90% for control and 96.67% for test experiment. In school C, 86.67% for
control and 100% for test experiment (Table2; figure 4).
(e) Circulatory System and Nerve Cells
Many students and teachers were so fascinated about these models. They found the models to be
very appropriate. However, no students’ marks were obtained when they were tried.
3.2 SURVEY RESULTS: RESULTS FROM QUESTIONNAIRES
Out of the 62 respondents the least percentage number who responded yes to questions asked was
88.71% (Table 2). Out of the number, 91.94% teach in junior secondary schools, 43.55% had GCE ‘O’
level and 43.54% had teaching experience below 10 years (Appendix 4). The feedback from
respondents to questions is in Table 3.
Table 3: Categories of questions and trend of responses obtained from teachers
Yes No QUESTION No. % No. % Models easy to work with? 59 95.16 3 4.84 Use of the models made teaching of topics easier
60 96.77 2 3.23
Models recommended for use in other schools?
58 93.55 4 6.45
Models worthy of use in other African countries?
55 88.71 7 11.29
How respondents reacted to whether there were any problems or not when
using the models
Nine (9) of the respondents did not find any problem. Seven (7) found problems with cells, 10 with
solar system, 15 with atoms, molecules and compounds, 4 with chromatography, 2 with the circulatory
system, 5 with acid-base indicators and non with nerve cells.
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 15
Common Suggestions by Respondents
?? More durable materials be used for animal cells. Also more features be put into the cells.
?? Better materials be used for the board for chemical equations.
?? Labels be written to show areas of the various models.
?? For the solar system, dry cells be used as source of generating light instead of electricity. Also the
balls should be completely of different sizes.
?? Stickers for chemical elements must be fixed more firmly.
Some Common Comments by Respondents
?? The models were recommended for teaching at all levels
?? The standard found to be good.
?? Models are original, versatile and can stimulate students.
?? Students’ interest in the lessons was high when the models were used and they generally made
lessons lively.
?? Great innovation. Ways be found to make more for teachers
?? They are less costly easy to use and students used them as some kind of games. It made students to
remember their subject matter easily.
?? This could be a bigger project to be funded by educational authorities in schools.
?? The materials and ideas quite good but need to be refined a bit.
4. DISCUSSION OF RESULTS
The marks obtained from the three schools that tried the models showed that marks of students who
were taught using the models were generally higher than marks for students who did not benefit from
the use of the models. For instance, in the case of cells, the difference between the percentage number
of students scoring marks above 40% for the test experiment and control were so high (Table 2). It is
the same case for two schools when the model for atoms, molecules and compounds were used. For the
third school the difference is not all that large but still more students scored higher marks when the
models were used. The pattern of marks when the solar system was used is similar to that of atoms,
molecules and compounds. For chromatography the marks for control and test experiments were very
close, but still higher marks were obtained when the model was used (Table 2). Considering the fact
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 16
that higher marks were generally obtained when the models were used, then it can be argued that the use
of the models enhanced the understanding of the topics by students when they were used.
The results of chromatography experiments showed that when black ink from BIC pen was used as the
mixture three distinct colour separations occurred in chalk stick when water was used as stationery
phase whilst only two colours were noticed on cassava and yam chips. This suggests that in water black
ink from BIC black pen ink can show better separation of its components when a stick of chalk is used.
The difference between the colour separation power of stick of chalk and that of yam chip and cassava
chip respectively may be due to different chemical compositions of the three as well \as differences in
the adsorption powers of the three. Again, the results also showed that for cassava and yam chips
KOFA ink could not separate into any of its components in water. This means that KOFA ink may not
be suitable when using cassava and yam chips as stationary phases with water as mobile phase. On the
contrary, when alcohol was used in place of water as mobile phase BIC black ink separated into various
components with more distinct colour bands along stick of chalk, cassava chip and yam chip.
However, separation was the best for stick of chalk. This suggests that alcohol is better to use as mobile
phase whenever using stick of chalk, cassava chip or yam chips as stationary phase. The reason may be
that alcohol can dissolve the mixture and break it into its components and carry it along, better than
water. KOFA black ink did not separate into its components along the chalk stick, cassava and yam
chips when alcohol was used as mobile phase. This suggests that even for chalk stick, alcohol may not
be used as mobile phase when KOFA black ink is used as the mixture.
When syringe was packed with materials and used as column, it was realized that whilst four colours
separated when starch was used as stationary phase and water as mobile phase, three colours separated
when maize powder or chalk powder was used as stationary phase and water as mobile phase and BIC
black ink as the mixture. Also, the separation started earlier in starch compared to maize powder and
chalk powder. This suggests that when water is used as the mobile phase in the column, starch as the
stationary phase would give better results than maize powder or chalk powder. The results also proved
that when alcohol was used as mobile phase, BIC black ink as the mixture, more colours were seen
separating along chalk powder than maize powder or starch. Thus, in alcohol BIC black ink showed
better results of separation along chalk powder. KOFA ink as the mixture in alcohol did not show any
distinct colours separation along starch and chalk, but two colours were noticed along maize powder.
This may mean that alcohol can be used to separate KOFA black ink when maize powder is used as
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 17
stationary phase. The results also showed that for either water or alcohol as mobile phase the red colour
was very distinct when maize powder was used as stationary phase. This may be that red can easily
dissolve in either water or alcohol and maize powder having high adsorption powder to carry it from its
mixture.
It is known that black ink is composed of many different colour components. The components also
show differential polarity (Vartak, 2001). This shows that different types of ink can show different
patterns of colour separation with different materials. Therefore it can be that the differences obtained in
patterns of colour separation of the two types of black ink with the solvents and the stationary phases are
normal.
The results of the acid-base indicators showed that:
?? Tomatoes extract apart from changing sodium hydroxide (NaOH) orange – green it did not show any
colour change with HCl, limejuice, Cocoa pod ash filtrate or plantain peel ash filtrate. However, the
orange –green, mixture changed colourless when hydrochloric acid (HCl) was added drop wise.
Also in lime the mixture changed light green when NaOH was added drop wise. These suggest that
tomatoe extract can be used as indicator in NaOH and for titration when NaOH and HCl are
involved in neutralization reaction. Drops of onion extract changed HCl solution and lime pink.
When NaOH was added to the mixtures they turn green. Onion extract also changed NaOH, cocoa
pod ash filtrate and plantain peel ash filtrate green. On addition of HCl or limejuice to the mixtures
they all changed colourless. Thus, onion extract is proving to be a very good organic indicator.
?? Ginger extract did not bring any visible colour change in HCl and limejuice but the mixtures turned
green on addition of NaOH. When ginger extract was added to NaOH solution, cocoa pod ash
filtrate, plantain peel ash filtrate, were decolorized when HCl or limejuice was added. Here again it
can be said that ginger extract can be used as an acid-base indicator. Similar results were obtained
by William and Sethumadhavan (1991) when they used grape juice, red apple skin extract and
tomato juice as indicators in acid base titration in India.
?? Limejuice showed colour change when onion or ginger extract was added. It also turned the mixture
of NaOH and onion or ginger extract colourless, thus behaving like the HCl used. This suggests that
limejuice can be a useful alternative to dilute mineral acids in case one cannot get acid to work with.
Similarly, cocoa pod ash filtrate and plantain pod ash filtrate showed colour changes with onion and
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 18
ginger extracts which change colourless on addition of HCl or lime juice. Thus, coca pod ash
filtrate and plantain peel ash filtrates are also potential alternatives for bases (alkaline).
Results from use of the indicator papers prepared showed that it was only that of onion which showed
colour change with NaOH and the two ash filtrates but not with HCl or lime juice. The indication is that
the onion paper indicator is behaving as red litmus paper, which remains red in acids. Thus, it can show
colour charge in bases (green colour) but still remain white in acids.
If the reactions of students and teachers to the models on circulatory system and nerve cells are anything
to go by then it can be said that they were accepted as useful teaching equipment.
Results collated from the questionnaire indicate that majority of respondents (91.94%) were teaching in
the junior secondary school (appendix 4). This is considered appropriate for the research because if
teachers at such lower level can effectively use the models and get positive results then its adoption in
the higher levels may not be a big problem. Out of the total respondents, 69.36% were either senior
Secondary School certificate or GCE ‘O’ level certificate holders before entering the training college
(Appendix 4). Since the teacher training college science in Ghana is not anything above what the
students had already acquired in the subject before their entry into the training colleges, it is appropriate
that majority of such teachers be used for this research so that they can benefit from the work and use it
in enhancing their teaching work.
It was also good that the respondents had varied periods of teaching experienced because the
contribution of the less experienced and the very experienced ones contributed greatly towards the
soliciting of array of views to be used for further improvement of the models. From the results, it is
clear that majority of the respondents (Table 3) agreed that the models were easy to use and
recommended their use in other schools in the country as well as in other African countries.
Though some of the respondents stated that they faced some problems when using the models, they gave
very good suggestions, which can be used to improve upon the models. Some of such suggestions
worthy of consideration are that more durable materials be used for the preparation of the models. In
some cases labels be added to show areas of the various models; dry cells be used in place of electricity
for the solar system. This is considered as a useful suggestion because many basic schools in Africa are
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 19
in rural areas where there is no electricity. Another suggestion, which was considered important, is that
care be taken to fix the necessary parts of the models so that they can work effectively.
Almost all the comments made by respondents showed that the teaching aids were acceptable to them
and that they are ready to adopt them. The comment that the models were great innovations, which
stimulated interest of students in lessons and made the lessons lively was very interesting. This also
shows that the project achieved its objective of stimulating the interest of students in science and to
enhance their understanding and performance in the topics.
5. CONCLUSIONS From the results of chromatography it can be concluded that both water and alcohol when used as
mobile phase can cause colour separation of BIC black ink along chalk stick, cassava chip and yam
chip. However, the best result can be obtained if chalk stick is used. Alcohol also provided better
results than water as mobile phase.
KOFA black ink separated into two colour components along only chalk stick in water. However, there
was no colour separation at all when alcohol was used. This shows that using water as mobile phase,
KOFA black ink or BIC black ink can be used as the mixture. However, BIC black ink provided a better
separation. Therefore chalk stick as stationary phase and water as mobile phase are recommended to
teachers at the basic level of education for teaching colour separation (chromatography) because
teachers can easily obtain these two things. However, for better results teachers can buy locally
manufactured alcohol (akpeteshie) if the school can afford. Also in the absence of chalk stick, cassava
chip or yam chip can be used. In this case too alcohol can give a better result than water. Because BIC
black ink can be obtained very easily, it is hereby recommended.
For columns, since separation occurred along the three stationary phases when water was used as mobile
phase with BIC black ink as mixture, then it can be said that starch, maize powder, or chalk powder can
be used for column chromatography when water is the mobile phase and BIC black ink as the mixture.
Syringe is also therefore recommended for use to be packed with the materials for the column
chromatography. However, for quicker results starch can be used instead of maize powder or chalk
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 20
powder. KOFA ink should be used only if BIC black ink is not available. Even then, water should be
used as mobile phase instead of alcohol.
From the results of acid base indicators it can be said that onion and ginger extracts can be used as
indicators. Therefore, they are hereby recommended for use by science teachers. Since limejuice is
acidic, it is then being recommended for use in place of acids in neutralization reactions (titration) and
test for colour change of indicators. Similarly, since the cocoa pod ash filtrate and plantain peel ash
filtrate exhibit the characteristics of bases in neutralization reactions and colour changes with the
organic indicators, they are therefore recommended to be used as bases if other bases are not available.
Since Students’ marks on four of the models showed that students who were taught using the models
generally had higher marks than those who did not benefit from the use of the models then it can be
concluded that the use of the models enhanced the understanding of the topics by students. Hence, it
will be of great value if the technology behind preparation of these models made available to more
teachers. It is also recommended that the knowledge of preparing the models be made available to
teachers in other African countries especially West and Central African sub-regions.
Further, it is suggested that more funds be solicited from relevant donors for more comprehensive work
to be done on the development and trials of more locally prepared science teaching aids. It may also be
of great help if toy manufacturing companies in the subregions can be contacted to find out how best
they can adopt these teaching aids and other good ones for improvement and mass production for sale at
moderate prices to schools in the subregions.
As suggested by respondents, efforts would be made to improve upon the models for the use by schools.
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 21
REFERENCES
1. Bhandula, N; Chadha, P.C., and Sharma, Swar Sidhe (1999): Teaching of Science, Parkash Brothers,
Ludhiama, p.181.
2. Mass, Douglas (1984): Molecular models for (Almost) Nothing, Chemistry Educational, October-
December, pp.35-37.
3. Samanta, Debojit and Mukherjee, Asok K. (1991): China-Rose extract: A natural acid-base
indicator, Chemistry Education, January-March, pp.58-59.
4. Sharma, C.R. (2001): Modern science Teaching, Dhanpatrai Pub. Co.; New Delhi, p.262.
5. Shedbalkar, V.P. (1988): Design for a simple and inexpensive glove box, Chemistry Education,
July-September, pp.47-48.
6. Vartak, Rajiv Rekha (2001): Chromatography: An Educational Tool, Resonance, May, pp.83-91.
7. William, Violet V. and Sethumadhavan R. (1991): Edible Indicators in Acid-base titration,
Chemistry Education, April-June, pp.57-58.
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 22
APPENDIX 1
PREPARATION OF THE MODELS
(a) CELLS (i) Plant cells Cardboard or plywood was cut into rectangular shaped pieces. (Note that plant cells can be rectangular,
square, hexagonal, Octagonal etc). Paper (A4) was cut into the shape of vacuoles and pasted in the
centre of the rectangular boards. Cotton thread 5 mm in diameter was glued round the vacuoles. Similar
thread of different colour was glued round adjacent to the vacuole to serve as the nucleus. Small stones
or cardboard pieces were glued inside the nucleus to depict the nucleoli. Another cardboard was cut into
pieces of particular sizes using a pair of scissors. These pieces of cardboard were cut into the shape of
the cristae shape of mitochondria. They were then glued all over in the cytoplasm of the model cell.
Another 5 mm diameter thread of different colour was glued round the cristae shaped mitochondria.
This made the structures to resemble the mitochondria as they appear in cells. The use of threads of
different colours was to differentiate the various organelles and for aesthetic reason to attract the
attention of the students that would use the model.
Another cardboard was cut into the shape of chloroplast. These pieces of cardboard were painted green
because chloroplasts are green due to the presence of chlorophyll. They were then glued in the
cytoplasm of the cell. The sizes of the different structures (organelles) glued in the cytoplasm were cut
into various sizes in proportion to other structures. Since plant cells have both cell membrane and cell
wall, pieces of cloth were glued at the edges of the rectangular board to depict cell membrane followed
by long flat pieces of cardboard as the cell wall.
(ii) Animal cells
Another set of cardboard or plywood was cut into spherical shapes (this is because though animal cells
can change shape, they are most often presented in the form of sphere). Pieces of cloth were glued at
the edges to depict cell membrane but no cell wall. Also there was no chloroplast but there were
mitochondria and a nucleus. Vacuoles were completely absent or very small ones were pasted close to
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 23
the periphery of the model. This is in line with the theory in which animal cells have only small
vacuoles at the periphery or may not have them at all
(b) ATOMS, MOLECULES AND COMPOUNDS (i) Atoms
A cardboard or plywood was cut into rectangular or
circular shape. Nylon or twin thread of a particular colour
was cut and pasted in a circular form in the middle of
each board. One half of hook loop (sticker) was cut into
pieces and glued inside the circular thread with the
adhesive part of the sticker upwards. Canes of diameter
1.5-2 cm were cut into pieces 1cm long and divided into
two sets. One set was painted green and the other set
painted brown. The green pieces were used as the protons
whilst the brown pieces were used as neutrons. White
paint was used to write positive (+) sign on all the green
pieces of cane. The second half of the hook loop (sticker)
mentioned earlier was cut into pieces and glued on both
the green and brown pieces of cane with the adhesive part of stickers outside. With the aid of the
sticker, the green and brown pieces of cane were put in position in the middle of the circular thread.
This represents the nucleus of the atom made up of protons and neutrons.
Another thread with different colour was glued round the nucleus in succession to depict the shells.
Another cane with smaller diameter (0.5 – 1 cm) than those used for the protons and neutrons was cut
into pieces as before. They were painted red and marked negative (-) with white paint. Stickers were
pasted on them as in the case of protons and neutrons. Similarly, the other half of the stickers were cut
into pieces and glued on the circular nylon threads surrounding the nucleus.
Now, since the number of protons in the nucleus equals number of electrons surrounding the nucleus of
an atom, the number of green pieces of canes in the nucleus is always equal to the number of red pieces
on the shell. Thus, a loss of an electron means that there is one extra proton (positive charge, and in this
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 24
case green piece of cane) in the atom than electrons (negative charges and in this case red pieces of
cane). Hence the atom will have a charge of positive one (+). On the other hand, a gain of one electron
means that there is one extra electron (negative charge) than protons (+). Hence, the atom shall have a
charge of negative one (-).
The mass number is equal to the sum of protons and neutrons in the nucleus of the atom (i.e. greens +
brown pieces of cane). Thus, counting both the green (protons) and brown (neutrons) pieces of cane in
the nucleus of the model will give the student the mass number of the atom.
(ii) Molecules and compounds
Cardboard materials were cut into the symbols of various chemical elements, equal sign (=), minus sign
(-) and positive signs (+). Similarly, cardboards were cut into the shape of figures such as 1,2,3,4, and
5. The non-adhesive half of a strip of hook loop (stickers) was glued to the letters, symbols, signs or
figures with the adhesive part exposed. A plywood or cardboard was cut into the shape of a rectangular
board 60 cm by 150 cm. The other half of the hook loop (sticker) was stretched and pasted on the
rectangular board in straight lines with the adhesive part up. The board was used as a chalkboard. With
the aid of the stickers, the chemical symbols, figures and signs were used in writing ions, molecules and
compounds.
Using the model atom built, the
chemical symbols, figures, equal sign,
plus and minus signs were used in
writing ions. For example, using
sodium atom, there are eleven (11)
protons and eleven (11) electrons.
However, the outermost electron shell
contains 1 electron, which is far short of
the 8 needed to have a complete
outmost electron shell. In this case
sodium atom easily loses the single electron in the outer most shell. Since number of protons equals
number of electrons, this loss means it is left with 10 electrons (negative charges) in the atom whilst
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 25
there are still 11 protons (positive charges). Thus, there is one extra proton (+ charge) with no
corresponding electron (- charge). So by picking the symbol of sodium (Na) and sticking it on the board
and a single positive sign representing the single extra positive charge is pasted at the top right hand
corner of the symbol (Na +). This forms cation. Similarly, chlorine has 17 protons (+ charges) and 17
electrons (negative charges). The outer most electron shell contains 7 electrons. Thus, it needs only one
electron to have 8 electrons required in the outer most shell. On gaining this single electron (negative
charge) to become 8 electrons, there are now 18 electrons (negative charges) compared to 17 protons (+
charges) in the nucleus. Thus, there is one excess negative charge. So, if the symbol of chlorine (Cl) is
pasted on the board and the single negative charge (-) is placed in the top right hand corner of it, then
chlorine anion (Cl) is formed. Since positively charged and negatively charged atoms can combine to
form a compound, the two ions can come together to form a compound called sodium chloride (NaCl).
From this fundamental point of view, the two atoms exchange charges to form the compound.
The equations can also be balanced by pasting the relevant figures on the left hand side in front of the
relevant compounds and symbols after the formation of the compounds. These can all be undertaken in
class with students in the form of a game or play.
Later, the teacher can then introduce the students to the presentation of the atom structure, ions,
molecules, compounds and balancing of equations on the chalkboard and in their books.
(c) SOLAR SYSTEM
A half-centimeter thick plywood board was cut 90
cm by 120 cm long. It was then shaped into the
form of sphere and painted to depict the colours of
the skies. A very big ball painted yellow was glued
to one end of the board. Different plastic balls of
different sizes depicting the sizes of the various
planets were painted with different colours, taking
into consideration the features of each planet as it
can be found in literature. These balls wee glued on
the board from the ball representing the sun in such a way to show the position of each planet from the
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 26
sun in relation to other planets. Thus, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune
and Pluto were displayed. Lines were drawn with chalk from the balls round the ball representing the
sun. These lines represent the orbits of the various planets.
Another plywood board with the same dimensions as above was painted with colours as the first board.
The centre of the board was determined. Nine lines were drawn in the form of spheres round the centre
with the chalk. These lines depict the orbits of the planets. A four-inch nail was used to punch holes on
the orbits.
Plastic balls of various sizes were painted to depict features on the planets as literature states. These
balls were punched at particular points with pointed knife. A nylon rope 0.4 mm thick was cut into nine
pieces each 45 cm long. A knot was made at one end of each of these ropes and pushed into each of the
balls. The other end of each rope was pushed through the holes on the orbits on the board with each
planet in its appropriate position from the sun. Another knot was made at the end of the rope on top of
the board to hold the planets hanging.
A three-inch nail was driven into the side of a
stand 75 cm tall. An electric bulb connected with
wire was then hanged on the nail. The bulb
represents the sun. The centre of the board
bearing the balls was then placed on the stand and
placed on a table. When this is done the balls are
seen hanging. The hanging balls represent the
various planets in the solar system. Three rings
prepared by cutting a cardboard into a circular
ring were placed on the circumference of the ball representing Saturn. A plug was fixed on the wire
connected to the bulb, when the plug is fixed into a socket and switched on, the bulb produces light, thus
representing the sun. When the board is given a push round, it revolves round on the stand thus carrying
the balls round the bulb. This demonstrates revolution of the planets. Meanwhile efforts are being
made to modify the set-up so that the balls can revolve individually. To demonstrate rotation, the rope
hanging on each ball can be pulled on top of the board and rolled round to depict rotation.
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 27
(d) COLOUR SEPARATION (CHROMATOGRAPHY)
(i) Using Chalk Stick, Cassava and Yam chips
A constriction was made 1 cm from one end of a stick of chalk, cassava chip or yam chip. Black ink
from BIC pen was spilled into a small bottle and a little thinner added to it to make it more fluid. Two
drops of the ink were applied to the constricted region of the stick of chalk, cassava chip and yam chip
and allowed to dry up. A little water was poured into three small flat basins and the chalk stick, cassava
chip and yam chip was placed in the middle of the water in each of the basins making sure that the ink
mark was above the water. Alcohol was used in place of the water. Alternatively, ink with the trademark
name KOFA was also used.
(ii) Using Columns
A piece of cotton wool was put into the constricted region of the barrel of a syringe by using copper
wire. Fine sand was put on the cotton wool to the depth of about 3 mm. Chalk powder was then put on
the sand 2-3 cm thick. About 4 mm of sand column was then added. Water was added to the column
leaving empty space above. Two drops of black ink diluted with thinner were added to the water above
the column and the set –up left to settle. Observation for colour separation was made in place of chalk
powder, starch powder, and maize powder were used and observations made. In place of black ink from
BIC pen, black ink with the trademark name KOFA was used. In place of water, alcohol distilled
locally (Akpeteshie) was used as the mobile phase.
(e) CIRCULATORY SYSTEM
A foam mattress (2 inches thick) was cut into the shape of the longitudinal section of the heart and
pasted on plywood. Two plastic bottles were fixed in the positions of the auricles (atria) above and two
in the positions of the ventricles below. Holes were made in the lids of the bottles. Other holes were
made at the top of the two bottles in the positions of the ventricles. The four plastic bottles were then
connected up with small water hose. Two plastic bottles were fixed at the back of the plywood. The
bottle on the left of the heart represents the body and the head, and the other on the left of the heart
represents the lung. The bottle representing the body was connected to the left ventricle with a small
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 28
water hose passing through a larger water hose painted red. This larger red hose represents the aorta.
Oxygenated blood from the heart flows through it to the body and the head. The bottle representing the
lung was connected to the right ventricle by a small white water hose passing through a larger water
hose painted green. The larger green water hose here represents the pulmonary artery. Deoxygenated
blood from the heart flows through it to the lungs. The bottle representing the lung is in turn connected
to the bottle fixed in the column of the left auricle with a small white water hose through bigger water
hose painted red. This bigger red water hose represents the pulmonary vein. Oxygenated blood flows
through it into the left auricle. The bottle representing the body and head was connected to the bottle
fixed in the column of the right auricle
with a small white water hose through
a bigger water hose painted green. The
bigger green water hose here
represents the vena Cava.
Deoxygenated blood passes through it
into the right auricle.
When the set up is filled with water or
any red liquid, it is used to demonstrate
the flow of blood in and out of the
heart through pressing or contracting the bottles.
When the bottles in the columns representing the auricles are filled with water and the bottles pressed or
contracted after tilting the upper part of the model the water flows through the white water hose into the
two bottles representing the ventricles. When the model is tilted from the bottom in the direction of the
auricles and the two bottles representing the ventricles pressed, the water flows through the white water
hose into the bottles behind the board, representing the body and the lung.
(f) NERVE CELLS
A wooden board 1metre long was cut into two and a hinge fixed in between them so that it can be folded
when necessary. One metre of wire 3 mm thick was cut into three. Two of the pieces were 40 cm long
each while the third one was 20 cm. A 4-inch nail was driven into the wooden board at one end. One
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 29
end of the longer piece of wire was tied to the nail on the wooden board. This piece of wire represents
sensory neurons. A 4 paper was cut into pieces 9cm long and with the aid of glue these pieces of paper
representing the myelin sheath were folded round the wire leaving gaps at intervals. The gaps represent
nodes of Ranvier. The wire represents the axon. A piece of thick paper was cut into the shape of the cell
body in the dorsal ganglion and fixed on the wire before the last section of myelin sheath. The end of
the wire was unfolded into fine smaller pieces. This represents dendron. Each of these pieces was
unfolded into fine smaller pieces to represent the dendrites.
The two ends of the shorter (20 cm
long) wire were also treated as above.
Each of the five smaller pieces
representing the dendrons was fixed
into star shaped material made from an
old rubber shoe. This star shaped
structure represents the cell body. A
red paint was used to make round
marks in the middle of the star-shaped
materials. These represent the nuclei
of the cell bodies. One end of the
second long (40 cm) wire was treated as that of the short one. Pieces of papers were glued around it as
in the first one. The second end of this wire was unfolded into smaller pieces. Five pieces of a 4 paper
0.5 cm broad and 8 cm long were then glued to the unfolded end.
The wires were then put end to end at the points separated. Two shallow plastic basins containing water
were placed at the junctions. The water in the basins represents a chemical substance called
acetylchboline normally secreted by the synaptic joints when stimuli reach such joints. The
aceytylcholine conducts impulse from one nerve cell to another. Generally whenever the wire with one
end rolled round a nail is tapped a number of times after the connection, the impulse is transmitted to the
third wire and it vibrates. This shows transmission of impulse across nerve cells.
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 30
(g) ACID-BASED INDICATORS
Hundred grams of tomatoes, 120 g of peeled ginger, and 100 g of onion were put into clean cooking
silver bowls or beakers separately. Hundred cubic centimeter of tap water was added to each material
and boiled for between 5 – 10 minutes making sure that the tomatoes do not break up in the water. The
extracts were then taken off the fire and allowed to cool down. One molar sodium hydroxide (NaOH)
and hydrochloric acid (HCl) were then prepared. Penicillin bottles were used as test tubes. Two
centimeters cube (2cm³) NaOH was put in a penicillin bottle and two drops of tomatoes extract added to
it with the aid of syringe and the colour change observed.
With the aid of another syringe, drops of HCl were added to the mixture until there was a colour change.
The experiment was repeated by using onion and ginger extracts respectively. In place of HCl,
limejuice was used and the colour changes observed.
Similarly, two drops of each of the edible extracts were added to 2 cm³ of Hcl and limejuice respectively
and the colour changes observed. To find a substitute for NaOH from an organic source, 100 cm³ of
water was added to 50 g of ash of cocoa pod and plantain peels respectively after burning. Each mixture
was filtered and the filtrates used in place of NaOH for the various experiments as above.
To prepare indicator papers of the edible extracts, A4 paper was cut into pieces measuring 5 mm by
5cm. Twenty of the pieces of paper were dropped into each edible extract and removed after 15
minutes. They were then dried by exposure to air. After drying samples of these pieces of paper from
each extract were dipped into the Hcl, NaOH, as well as cocoa pod ash and plantain peel ash filtrates to
find out if there can be colour change.
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 31
APPENDIX 2
ASSESSMENT OF THE SIMPLE SCIENCE TEACHING AIDS
This questionnaire is to assess the usefulness and workability of the simple science teaching aids that
you were introduced to. Tick the answer that you consider as appropriate. Try to be very objective. For
questions without option answers put your own opinion down in one or two simple sentences.
PERSONAL INFORMATION 1. Teaching experience: …………………………………………. 2. Level (form) being taught: …………………………………… 3. Level in Science: SSSCE, GCE ‘O’ Level, GCE
‘A’ Level Post Secondary teachers certificate, Specialists, Teachers diploma, 1st Degree, Masters, Ph.D, Others’. State …………….
…………………………………………………………… INFORMATION ON THE TEACHING AIDS
4. Do you find the teaching aids easy to work with? Yes, No 5. Did the use of the aids make teaching of topics easier?
Yes No.
6. What is your rating of the usefulness of the aids in relation to Teaching science? Very high, high, low, Very low,
7. Would you recommend the use of the aids in other schools in the country? yes, No.
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 32
8. Do you find the aids worthy using in other African Countries? Yes, No.
9. What problems did you encounter when using the teaching aids?
………………………………………………………………… 10. State which of the aids needs to be improved and how it can be improved upon.
a. Teaching aid (s): ………………………………………….
……………………………………………………………. ……………………………………………………………
b. How to improve upon it: …………………………………
11. Any special comments: ………………………………………
………………………………………………………
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 33
APPENDIX 3 (a) Marks obtained by students when the model cells were used (in JSS 1)
School A School B School C Control Test Experiment Control Test Experiment Control Test Experiment 20 60 37 94 45 83 38 40 42 86 51 64 36 26 40 78 15 79 25 72 61 91 65 58 33 95 73 96 42 46 40 94 48 68 67 93 66 80 18 64 80 38 49 99 29 82 13 59 42 64 70 97 71 79 36 96 47 70 26 82 27 68 63 90 56 73 22 60 83 97 67 65 79 88 64 69 08 84 00 81 49 78 73 80 77 45 52 90 47 77 32 68 70 93 09 46 30 100 38 81 49 67 70 67 81 95 38 87 30 88 56 78 78 96 10 56 60 97 62 55 43 100 40 76 35 74 08 20 32 95 44 95 25 59 51 58 52 78 33 64 80 62 11 83 30 65 33 79 76 69 09 60 70 94 69 44 00 99 15 98 29 90 39 58 70 97 38 87 30 80 61 93 81 86 44 20 55 87 59 76
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 34
(b) Marks obtained by students when model for atoms, ions, molecules and compounds were used
(in JSS 2)
School A School B School C Control Test Experiment Control Test Experiment Control Test Experiment 45 100 60 74 64 79 25 84 44 94 56 84 00 48 61 85 62 77 20 56 52 91 18 95 15 46 27 68 47 58 26 00 23 54 52 79 00 49 45 82 12 93 30 48 51 43 74 86 33 49 40 96 65 67 42 85 50 80 68 96 40 75 71 90 43 81 18 98 62 84 71 76 21 67 40 77 82 49 60 100 16 68 39 87 38 61 53 80 57 66 40 89 30 93 68 79 39 62 48 91 65 59 8 97 10 43 77 82 26 64 55 98 47 92 62 82 36 67 83 69 35 85 42 60 68 94 47 66 50 69 54 47 10 63 60 94 48 90 17 67 36 72 70 82 44 60 20 100 76 78 30 40 80 57 73 75 39 26 39 89 59 91 00 72 52 99 64 80 09 95 40 73 80 77 30 94 30 50 48 86
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 35
(c) Marks obtained by students when the solar system model was used (in JSS 3)
School A School B School C Control Test Experiment
Control Test Experiment
Control Test Experiment
35 63 27 86 81 72 62 48 13 97 47 63 73 78 50 78 71 78 60 92 60 81 66 59 18 88 82 94 56 80 51 26 25 43 52 49 12 76 34 60 80 55 51 64 40 76 60 64 27 85 50 90 61 81 08 81 63 81 71 78 40 72 70 72 42 67 77 57 18 84 75 96
25 69 29 80 40 53 58 65 70 92 57 89 62 44 40 67 69 72 35 98 36 54 49 94 48 38 22 67 69 90 81 89 50 73 48 79 33 74 67 83 67 47 06 49 70 94 55 72 67 69 81 81 51 84 78 51 14 53 50 63 46 87 20 94 49 86 56 92 35 73 65 98 58 95 20 63 52 51 49 80 55 78 72 44 19 71 60 89 53 93 29 68 70 100 60 83 80 47 15 51 73 91
79 86 60 70 62 68
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 36
(d) Marks obtained by students when the set-up for chromatography was used in teaching
(in JSS 2)
School B School C Control Test Experiment Control Test Experiment 56 79 44 90 38 68 50 77 58 62 61 59 81 88 48 62 49 56 38 54 67 76 57 80 62 91 54 48 73 85 60 72 43 45 49 91 57 66 52 91 62 94 66 73 79 83 78 85 37 40 41 56 75 65 33 63 45 88 47 42 66 86 56 84 78 95 79 67 82 72 65 93 52 57 80 65 69 47 56 74 46 87 45 41 55 90 28 54 36 68 74 94 48 62 69 52 57 75 29 46 61 64 57 70 73 94 81 68 50 81 70 84 46 53 46 62 61 49 58 86
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 37
APPENDIX 4
Academic level in science, levels being taught, and teaching experience of respondents
Academic Level in Science Levels Being Taught Teaching Experience Level
% respondent
Level
% respondent
of No. years
% respondents
SSSCE
GCE‘O’Level
GCE‘A’ Level
Specialist
Diploma
Degree
25.81
43.55
12.90
9.68
3.23
4.84
JSS
SSS
Teacher Tr.
College
91.94
4.84
3.23
Below 10
Below 20
Below 30
Above 30
43.54
29.03
17. 74
9.68
Science teaching, ERNWACA-Ghana, Small Grants Program research February 2003 / Page 38
UNIVERSITY OF EDUCATION, WINNEBA INSTITUTE FOR EDUCATIONAL DEVELOPMENT AND EXTENSION. ACCRA STUDY CENTRE. C/O ACCRA TRAINING COLLEGE P.O. BOX 221 LEGON, ACCRA GHANA 14TH FEBRUARY 2003
The Regional Coordinator ERNWACA Dear Sir/Madam, RE: PRESENTATION OF PROJECT REPORT I present to you the end of project report on the project entitle “ Development of simple Aids for teaching science in basic schools”. Thanks. Yours faithfully, Wisdom Harrison K. HORDZI (PRINCIPAL RESEARCHER)
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