Measurement and Scaling Measurement o Measurement means assigning

Measurement and Scaling

Measurement o Measurement means assigning numbers or other symbols to characteristics of objects according to certain pre-specified rules. o Here, what we measure is not the object, but some characteristics of it. Thus, we do not measure consumers – only their perceptions, attitudes, preferences or other relevant characteristics.

Scaling o Scaling involves creating a continuum upon which measured objects are located. o A scale is a tool or mechanism by which individuals are distinguished as to how they differ from one another on the variables of interest to our study.

Nominal Scale o A nominal scale is one that allows the researcher to assign subjects to certain categories or groups. These groups can be assigned code numbers 1 or 2. o The information that can be gathered from nominal scaling is to calculate the percentage or frequency group objects.

Cont… o Your Gender _______ Male _______ Female o Your Department _______ Production _______ Marketing _______ Finance _______ HR

Ordinal Scale o An ordinal scale categorizes the variables to denote the differences among the various categories as well as rank-orders the categories in some meaningful way. o It indicates relative position, not the magnitude of the differences between the objects. o The preference would be ranked and numbered 1, 2 and so on.

Cont… o Rank the following brands of PCs with respect to their usage in your office, assigning the number 1 to the most used system, 2 to the next most used and so on. ___ Apple ___ HP ___ Compaq ___ IBM ___ Dell ___ Sony

Interval Scale o Interval scale is used where the differences between objects are to be compared. Here, zero point is arbitrary o It not only groups individuals according to certain categories and taps the order of these groups, but also measures the magnitude of the differences in the preferences among the individual variable.

Cont… o Rank the following features of Service Quality: Features 1. Tangibility 2. Assurance 3. Effectiveness 4. Reliability 1 2 3 4 5

Ratio Scale o Possesses all the properties of nominal, ordinal o o and interval scales. It allows the researchers to identify or classify objects, rank order the objects and compare intervals or differences. The origin or zero point is fixed. Not only is the difference between 2 and 5 the same as the difference between 14 and 17, but also 14 is seven times as large as 2 in an absolute sense. Common examples of ratio scales are height, money, age, sales, costs, market share, etc.

Cont… Please indicate the number of children you have in each of the following categories: ___ below 3 years of age ___ between 3 and 6 ___ over 6 years but under 12 years ___ 12 years and over

Primary Scales of Measurement Scale Nominal Ordinal Numbers Assigned to Runners 8 3 Rank Order of Winners Interval Performance Rating on a 0 to 10 Scale Ratio 7 Time to Finish, in Seconds Third place Second place First place 8. 2 9. 1 9. 6 15. 2 14. 1 13. 4 Finish

Illustration of Primary Scales of Measurement Nominal Scale Ordinal Scale Interval Scale Ratio Scale No. Store Preference Rankings Preference Ratings 1 -7 11 -17 $ spent last 3 months 1. Next 2. Sales India 3. Samsung 4. LG 5. Sony 6. Philips 7. Godrej 8. Hyundai 9. Videocon 10. Onida

The Characteristics of Good Measurement o Validity – the degree to which a test measures what we actually wish to measure o Reliability – has to do with the accuracy and precision of a measurement procedure o Practicality – is concerned with a wide range of factors of economy, convenience and interpretability

Validity Estimates Type What is Measured Methods Content Degree to which the content of the items adequately represents the universe of items Judgmental, panel evaluation with content validity ratio Criterion Related Degree to which the predictor is adequate in capturing the relevant aspects of the criterion Correlation Concurrent Description of the present; criterion data are available at the same time as predictor score Correlation Predictive Prediction of the future; criterion data are measured after the passage of time Correlation Construct What accounts for the variance in the measure, attempts to identify the constructs being measured Judgmental, correlation, convergent, factor

Reliability Estimates Type Coefficient What is Measured Methods Test-Retest Stability Reliability of a test or instrument inferred from examinee scores; same is administered twice to same subjects over an interval of less than six months Correlation Parallel Forms Equivalence Degree to which alternative forms of the same measure produce same or similar results; administered simultaneously or with delay, estimates of similarity of judgments Correlation Split Half, KR 20, Cronbach’s Alpha Internal Consistency Degree to which instrument items are homogeneous and reflect the same underlying construct/s Specialized correlations formulas

Practicality o Economy o Convenience o Interpretability