1. Sampling Design & Measurement Scaling
Dr. Kishor Bhanushali

2. sampling
CENSUS AND SAMPLE SURVEY
IMPLICATIONS OF A SAMPLE DESIGN

3. STEPS IN SAMPLE DESIGN Type of universe Sampling unit Source list
Size of sample
Parameters of interest
Budgetary constraint
Sampling procedure

4. Systematic Bias 1. Inappropriate sampling frame
2. Defective measuring device
3. Non-respondents
4. Indeterminacy principle
5. Natural bias in the reporting of data

5. CHARACTERISTICS OF A GOOD SAMPLE DESIGN
(a) Sample design must result in a truly representative sample.
(b) Sample design must be such which results in a small sampling error.
(c) Sample design must be viable in the context of funds available for the research study.
(d) Sample design must be such so that systematic bias can be controlled in a better way.
(e) Sample should be such that the results of the sample study can be applied, in general, for the universe with a reasonable level of confidence.

6. Non-probability sampling and probability
Sampling from finite population and infinite population
purposive sampling
Judgement sampling
Quota sampling
Simple random sampling
Systematic sampling
Stratified sampling
Cluster sampling
Area sampling
Multi-stage sampling
Sampling with probability proportional to size
Sequential sampling

7. MEASUREMENT
Measurement is a relatively complex and demanding task, specially so when it concerns qualitative or abstract phenomena
By measurement we mean the process of assigning numbers to objects or observations
properties like weight, height, etc., can be measured directly with some standard unit of measurement, but it is not that easy to measure properties like motivation to succeed, ability to stand stress and the like
Technically speaking, measurement is a process of mapping aspects of a domain onto other aspects of a range according to some rule of correspondence

8. MEASUREMENT SCALES
Nominal scale :simply a system of assigning number symbols to events in order to label them. - basketball players
Ordinal scale : places events in order - student’s rank
Interval scale : intervals are adjusted in terms of some rule, lack of a true zero - Fahrenheit scale
Ratio scale : absolute or true zero of measurement-height, weight, marks

9. Sources of Error in Measurement
Respondent : reluctant to express strong negative feeling, fatigue, boredom, anxiety,
Situation: distortions
Measurer: behaviour, style and looks
Instrument :defective measuring instrument, complex words

10. Tests of Sound Measurement
Validity ,Reliability, Practicality
Validity refers to the extent to which a test measures what we actually wish to measure : (i) Content validity, (ii) Criterion-related validity, (iii) Construct validity
Reliability has to do with the accuracy and precision of a measurement procedure : For instance, a scale that consistently overweighs objects by five kgs., is a reliable scale, but it does not give a valid measure of weight
Practicality is concerned with a wide range of factors of economy, convenience, and interpretability

11. TECHNIQUE OF DEVELOPING MEASUREMENT TOOLS
(a) Concept development; (b) Specification of concept dimensions; (c) Selection of indicators; and (d) Formation of index.

12. Scaling measurement problem in measuring attitudes and opinions
procedures for attempting to determine quantitative measures of subjective abstract concepts
Scaling describes the procedures of assigning numbers to various degrees of opinion, attitude and other concepts
(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

13. Scale Classification Bases
(a) subject orientation; characteristics of the respondent (b) response form; categorical and comparative (c) degree of subjectivity; subjective personal preferences or simply make non-preference judgement (d) scale properties; nominal, ordinal, interval and ratio scales (e) number of dimensions : ‘unidimensional’ and ‘multidimensional’ scales (f) scale construction techniques

15. The graphic rating scale
The itemized rating scale

16. Method of paired comparisons
Method of rank order
Under this method of comparative scaling, the respondents are asked to rank their choices

17. Thanks