Lec7 ARM Measurement

7/30/2019 Lec7 ARM Measurement

http://slidepdf.com/reader/full/lec7-arm-measurement 1/26

Ahmed Arif



Measurement is to discover the extents,dimensions, quantity or capacity of something

Measurement in research consists of assigningnumbers to empirical events in compliance with aset of rules.

Measurement in research comprises of three parts:◦ Selecting observable empirical events.

◦

Developing a set of mapping rules◦ Applying the mapping rule(s) to each observation of that

event.



Numbers are assigned to things, being or

events to classify or identify them.

◦

Assignment of numbers to different cricket players◦ Assignment of numbers to different type of responses

This type of scale is usually used when events,

beings or things are mutually exclusive.

The things or events can be uniquely identified.



Preferences are ranked in this scale. Greater than or less than is implied here, but

does answer how much greater or lesser.

Ordinal scales are used to make comparisons.

Ordinal scale works on transitivity postulate.

Increase in Sales 2

Increase in Revenue 1

Increase in Customers 3

Decrease in Cost 4



Interval between different successive

positions is equal.

It does not contain absolute zero.

Calendar time is an example of Interval Scale



It may contain absolute zero.

It include multiplication and division.

It is usually used for physical dimensions.

This is the most powerful scale.



Nominal Unique definition of numerals (0, 1, 2 ...)

Brands, Male-Female,Sales Territories

Ordinal Order of Numerals(0<1<2<3<....)

Attitudes, Preferences,Occupation etc.

Interval Equality of Different (2-1= 7-6)

Attitudes, Opinions, IndexNumbers

Ratio Scale Equality of Ratios (2/4 =4/8)

Age, Costs, Number of Customers



7 38

Scale

Nominal NumbersAssigned

to Runners

Ordinal Rank Orderof Winners

Interval Performance

Rating on a0 to 10 Scale

Ratio Time to

Finish, inSeconds

Thirdplace

Secondplace

Firstplace

Finish

Finish

8.2 9.1 9.6

15.2 14.1 13.4



1•Concept Development

2 •Specification of Concept Dimension

3•Selection of Indicators

4•Formation of Index



A good understanding of the topic. This stage is crucial when the concepts are more

abstract.

Research should clarify the dimension of thebroader concept.

Indicators are devices which measure knowledge,opinion and choices.

The researchers combine all the indicators into asingle similar index.



Criteria for

Good

Measurement

Validity

PracticalityReliability



Validity refers to the ability of an instrumentof to measure what it is expected to measure.

It is not easy to measure the validity of ascale.

However, certain methods have beendeveloped by the researchers to measure thevalidity .



Content validity means that how muchcoverage is provided in the instrument for thesubject.

If the instrument contains sufficient sample

of different concepts then content validity isgood.

There is no quantitative method for thisvalidity.

Usually the expert practitioner of theparticular field are contacted for the contentvalidity.



Involves the usage of some criterion to judgethe validity of measuring instrument.

Usually, it is done by comparing twoinstrument on which researcher hasconfidence.

There are two ways of Criterion-RelatedValidity:◦

Concurrent Validity◦ Predictive Validity



Show the usefulness of test by closelyrelating it to other measures of knownvalidity.

For example, you are measuring retention byan instrument and the results show highretention level. The organization will have thefigure of turnover, if this figure is low thenthe instrument has concurrent validity.



Shows the utility of a measurement tool inpredicting some future events.

For Example if an instrument measure therelationship of knowledge of workers andtheir performance.

If people with high score perform good thenthat instrument will have predictive validity.



This type of validity is performed by the

researchers of that particular field.

There should be compatibility between

theoretical concepts and measuring

instrument.

There are two categories of construct validity:◦ Convergent Validity

◦ Divergent/Discriminate Validity



Convergent validity is established when twovariables are supposed to be correlatedaccording to theory.

This validity is established when two variables

that are supposed to have no correlationtheoretically are found to be uncorrelated.



Reliability refers to consistent outcomes of an

instrument.

A valid scale must be reliable but a reliablescale may not be valid.

However, reliability testing is easier than

validity testing.



Test-Retest Method Same instrument is checked on different

times with same group.

Parallel-Form Method

Different forms of same questionnaire aretested.



Item Total Analysis The items of instrument measuring the same

construct are checked for the correlations. If all items are positively correlated, instrumentis reliable.

Inter Item Consistency – Cronbach’s Alpha

If items have an element of consistency with

each other. Cronbach Alpha should a value greater than

0.6.



It is measured in terms of economy andconvenience.

Economy aspect is related to costconsideration of measurement.

Convenience refers to the ease of administering the questionnaires torespondents.



Errors due to Interviewer

Errors due to Respondent

Errors due to Instrument

Errors due to Situation



Qualitative concept cannot be measuredeasily.

The concept like length, weight profitabilitycan be measured easily with a standard scale.

Bus a concept like success cannot bemeasured easily.◦ Success means high designation for some one.◦ It may mean high income for some one other.

Scaling is a branch of measurement that triesto measure immeasurable qualitativephenomenon with accuracy.



Scaling refers to the procedure in whichnumbers or other symbols are assigned to aproperty of objects.

There are highest and lowest points in a scalewith several intermediate points betweenthese two.

In the scale, from lowest to highest points, all

points exhibit an increasing degree of anycharacteristic.

Lec7 ARM Measurement

Documents

Transcript of Lec7 ARM Measurement