Educational research and Statistics

Types of instruments (Observation schedule, Rating Scales, Criterion for

selection of instrument)

Observation Schedule

• Observation schedule is a method in which data in the field is collected with the help of observation by observer.

• Types of observation method:

• Structured and unstructured observation

• Controlled and uncontrolled observation

• Participant and non participant observation.

Components of observation schedule

• An observation schedule should include items that

• are relevant to the research questions or other objectives of the survey

• are appropriate for the culture and environment

• do not require effort beyond observation

• can be completed within the time constraints of the survey

• are clearly formatted and leave space to write observations

• When observation is done without any thought before observation then it is called unstructured observation.

Un structured observation

• When observation is done by characterizing style of recording the observed information ,standardize condition of observation, definition of the units to be observed, selection of pertinent data of observation then it is structured information.

Structured observation

Structured and Unstructured Observationon

• When observer is observing people without giving any information to them then it is called non participant observation.

Non participant observation

• When observer is a member of group which he observing then it is called participant observation

Participant observation

Participant and Non partcipant observation

• When observation is take place in natural conditions then it is called uncontrolled observation.

Un controlled observation

• When observation is take place according to definite pre arranged plan, with experimental procedure then it is called controlled observation.i.e observation done in laboratory under controlled conditions

Controlled observation

Controlled and Uncontrolled observation

• It requires more time

• Extensive training is needed.

Disadvantages of observation Advantage of observation

Advantages and Disadvantages of observation

• Relatively inexpensive method

• The observation technique can be stopped or begun at any time.

• Subject are usually available.

• Information researcher get is current information.

Definition (Rating scale)

• Barr & others define rating as: “Rating is a term applied to expression of opinion or judgement regarding some situation, object or character. Opinions are usually expressed on a scale of values. Rating techniques are devices by which such judgements may be quantified”.

• A rating scale is a device by which the opinion concerning a trait can be systematized.

Types of rating scale

• Numerical Rating scale

• Descriptive Rating Scale

• Graphical Rating Scale

• The rank Order Scale

Numerical rating scale

• A scale in which numbers are assigned to each trait. If it is a seven point scale . The number 7 represents the maximum amount of that trait in the individual, and 4 represents the average .The rater merely enters the appropriate number after each name to indicate judgment of the person

• A B C D E F G

• 1 2 3 4 5 6 7

Descriptive graphic scale

• In which descriptive phrases or terms assigned to each trait. The rater enters the appropriate phrase after each name to indicate judgement of the person

• .A B C D E

Excellent Good Average Below average poor

Graphical rating scale

• A straight line, may be represented by descriptive phrases at various points. To rate the subject for a particular trait a check mark is made at the particular point.

Low Moral Good Moral High Moral

0 25 50 75 100

The rank order rating scale

• In this type the judge is simply required to place the people being rated in a rank order from high to low on the attitude or opinion in question. A given individual’s scale position is given in relation to other people in the sample. The units of the scale are unequal.

Criterion for selecting instrument

• Validity

• Reliability

• Expense(low maintenance)

• Reliability is " consistency" in measurement.

• Reliability is getting the same result by repeating the measurement.

• Reliability is the degree to which an assessment tool produces stable and consistent results.

Reliability Validity

Validity and Reliability

• Validity is "truth" in measurement.

• Validity is the extent to which a concept,conclusion or measurement is well-founded and corresponds accurately to the real world.

• The validity of a measurement tool is considered to be the degree to which the tool measures what it claims to measure.

• Validity and Reliability are closely related.

• A test cannot be considered valid unless the measurement resulting from it are reliable

• Likewise, result from a test can be reliable and not necessarily valid

Relationship between validity and reliability

Conditions

Valid but not reliable

• Valid because the pattern is evenly distributed around the correct goal(center): the person probably tried to hit the center

• Not Reliable: because the shots are off the mark in every possible direction they are not consistent

• Reliable: pattern shows the shot hit the same part of the target each time: it is consistent so it is reliable

• Not valid: the goal to hit the center of target ,but the shot are not in the same area

Reliable but not valid

Neither reliable nor valid

• Not reliable : because the shots are not consistent

• Not valid: because to the extent there is any pattern , it is not at a true target, the center

Why do Reliability and Validity matters?

• Data is gathered through measurement procedure.

• The score only have meaning if they measure what they are supposed to measure(validity) and do so with accuracy and consistency. (Reliability)

• Evaluating whether data are reliable and valid is a key element for selecting instrument.