Chapter 5

Chapter 5

1. Measurement in Research

   • Technically speaking, measurement is a process of mapping aspects of a domain onto other aspects of a range according to some rule of correspondence. In measuring, we devise some form of scale in the range (in terms of set theory, range may refer to some set) and then transform or map the properties of objects from the domain (in terms of set theory, domain may refer to some other set) onto this scale.

2. Measurement Scales

   • From what has been stated above, we can write that scales of measurement can be considered in terms of their mathematical properties. The most widely used classification of measurement scales are: (a) nominal scale; (b) ordinal scale; (c) interval scale; and (d) ratio scale.
     • (a) Nominal scale: Nominal scale is simply a system of assigning number symbols to events in order to label them.
       • (b) Ordinal scale: The lowest level of the ordered scale that is commonly used is the ordinal scale.
         • (c) Interval scale: In the case of interval scale, the intervals are adjusted in terms of some rule that has been established as a basis for making the units equal.
           • (d) Ratio scale: Ratio scales have an absolute or true zero of measurement. The term ‘absolute zero’ is not as precise as it was once believed to be.
   • Sources of Error in Measurement
     • Measurement should be precise and unambiguous in an ideal research study. This objective, however, is often not met with in entirety. As such the researcher must be aware about the sources of error in measurement. The following are the possible sources of error in measurement.
       • (a) Respondent: At times the respondent may be reluctant to express strong negative feelings or it is just possible that he may have very little knowledge but may not admit his ignorance.
         • (b) Situation: Situational factors may also come in the way of correct measurement.
           • (c) Measurer: The interviewer can distort responses by rewording or reordering questions
             • (d) Instrument: Error may arise because of the defective measuring instrument.

3. Tests of Sound Measurement

   • Sound measurement must meet the tests of validity, reliability and practicality. In fact, these are the three major considerations one should use in evaluating a measurement tool.
     • 1. Test of Validity* Validity is the most critical criterion and indicates the degree to which an instrument measures what it is supposed to measure.
       • 2. Test of Reliability The test of reliability is another important test of sound measurement. A measuring instrument is reliable if it provides consistent results
         • 3. Test of Practicality The practicality characteristic of a measuring instrument can be judged in terms of economy, convenience and interpretability.

4. Technique of Developing Measurement Tools

   • The technique of developing measurement tools involves a four-stage process, consisting of the following:
     • (a) Concept development; (b) Specification of concept dimensions; (c) Selection of indicators; and (d) Formation of index.

5. Scaling

   • In research, we quite often face measurement problem (since we want a valid measurement but may not obtain it), especially when the concepts to be measured are complex and abstract and we do not possess the standardized measurement tools
   • Meaning of Scaling
     • Scaling describes the procedures of assigning numbers to various degrees of opinion, attitude and other concepts. This can be done in two ways viz., (i) making a judgement about some characteristic of an individual and then placing him directly on a scale that has been defined in terms of that characteristic and (ii) constructing questionnaires in such a way that the score of individual’s responses assigns him a place on a scale.
   • Scale Classification Bases
     • The number assigning procedures or the scaling procedures may be broadly classified on one or more of the following bases:
       • (a) Subject orientation: Under it a scale may be designed to measure characteristics of the respondent who completes it or to judge the stimulus object which is presented to the respondent
         • (b) Response form: Under this we may classify the scales as categorical and comparative.
           • (c) Degree of subjectivity: With this basis the scale data may be based on whether we measure subjective personal preferences or simply make non-preference judgements.
             • (d) Scale properties: Considering scale properties, one may classify the scales as nominal, ordinal, interval and ratio scales.
               • (e) Number of dimensions: In respect of this basis, scales can be classified as ‘unidimensional’ and ‘multidimensional’ scales.
                 • (f) Scale construction techniques: Following are the five main techniques by which scales can be developed:
                   • (i) Arbitrary approach, (ii) Consensus approach, (iii) Item analysis approach, (iv) Cumulative scales, and (v) Factor scales

6. Important Scaling Techniques

   • We now take up some of the important scaling techniques often used in the context of research specially in context of social or business research.
     • Rating scales: The rating scale involves qualitative description of a limited number of aspects of a thing or of traits of a person
       • (a) Method of paired comparisons: Under it the respondent can express his attitude by making a choice between two objects, say between a new flavour of soft drink and an established brand of drink.
         • (b) Method of rank order: Under this method of comparative scaling, the respondents are asked to rank their choices.

7. Scale Construction Techniques

   • In social science studies, while measuring attitudes of the people we generally follow the technique of preparing the opinionnaire* (or attitude scale) in such a way that the score of the individual responses assigns him a place on a scale.
     • While developing such statements, the researcher must note the following two points: (i) That the statements must elicit responses which are psychologically related to the attitude being measured; (ii) That the statements need be such that they discriminate not merely between extremes of attitude but also among individuals who differ slightly.