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- 1. International Business Research Measurement of Variables: Scaling, Reliability, Validity Joseph Owusu, PhD Department of Marketing and Corporate Strategy Ksb-Knust
- 2. Objectives • To understand how research variables are measured • Discuss types of scales • Discuss the basic descriptive statistics in research
- 3. Measurement • To measure is to assign a value (number) to objects, events or outcomes of an event according to specified rules. • In a research project, the researcher does not measure the respondent but measures the characteristics of the respondent • The characteristics of interest for the study are called variables.
- 4. measurement • Example: consumer preferences towards certain food outlets, the researcher does not measure consumer but the variables such as consumer • Age • Gender • Preference • Perception • Attitude • Amount of purchase
- 5. Measurement • The researcher assigns numbers to objects of the study according to certain pre-specified rules. • The specification rules for assigning numbers or values to the characteristics of the objects are the most important aspect of measurement. • That is, the assignment of values or numbers to the object must be isomorphic. • Isomorphic means that there must be a one- to- one correspondence (relationship) between the figure and the characteristic being measured
- 6. Example: measurement of growth • Compared to other similar firms in the industry, our business over the past 3 years….. 1. Constantly experience increase in sales 2. Has employed more people 3. Has opened more branches 4. Has acquired sufficient assets 5. Constantly increased its market share •
- 7. Scale • Scale: tool or mechanism by which individuals are distinguished as to how they differ from one another on the variables of interest to our study.
- 8. Types of measurement scale Four Levels of Measurement scales 1. Nominal 2. Ordinal 3. Interval 4. Ratio
- 9. Nominal scale • A nominal scale is one that allows the researcher to assign subjects to certain categories or groups. • What is your department? O Marketing O Maintenance O Finance O Production O Servicing O Personnel O Sales O Public Relations O Accounting ▪ What is your gender? O Male O Female
- 10. Example of Nominal Scale • Marital status? Married Single Widowed Do you like chocolate ice cream? Yes No
- 11. Nominal Scale
- 12. Nominal scale
- 13. Ordinal ▪ Ordinal scale: not only categorizes variables in such a way as to denote differences among various categories, it also rank-orders categories in some meaningful way. ▪ What is the highest level of education you have attained? O Junior High School O Senior High School O University Degree O Masters Degree O Doctoral Degree
- 14. Ordinal
- 15. Example of ordinal scale • Rank the following brands of shampoo based on your preference Brand Your Rank 1 Follow 2 Vidal Sasson 3 Rejoice 4 Head and Shoulders 5 Sunsilk 6 Pantene
- 16. Ordinal scale
- 17. Interval Scale • Interval scale: whereas the nominal scale allows us only to qualitatively distinguish groups by categorizing them into mutually exclusive and collectively exhaustive sets, and the ordinal scale to rank-order the preferences, the interval scale lets us measure the distance between any two points on the scale.
- 18. Interval Scale Circle the number that represents your feelings at this particular moment best. There are no right or wrong answers. Please answer every question. 1.I invest more in my work than I get out of it I strongly disagree 1 2 3 4 5 I strongly agree 2. I exert myself too much considering what I get back in return I strongly disagree 1 2 3 4 5 I strongly agree 3. For the efforts I put into the organization, I get much in return I strongly disagree 1 2 3 4 5 I strongly agree
- 19. The numbers represent opinion 1. Strongly Disagree 2. Disagree 3. Not Sure 4. Agree 5. Strongly Agree
- 20. Interval Scale
- 21. Interval
- 22. Ratio Scale The ratio scale describe variables that have equal intervals between them but also have absolute zeros. Meaning that they are variables for which one possible value is zero. Ratio scales assign absolute rather than relatives quantities. Ratio scale is the highest level of measurement among the four scales. However in behavioural research interval scale is typically the appropriate measurements.
- 23. Example of ratio scale • How much do you pay for your rent? • How long does it take you to drive to the office everyday? • How many school-going children are there in your family?
- 24. Ratio Scale
- 25. Ratio
- 26. Classification of scale • There are so many ways of classifying scale of an object in the study. However most researchers employ 3 types • Categorical scale (voting scale) • Comparative scale (ranking scale) • Rating scale • Categorical scale (voting scale) • Dichotomous scale e.g., Do you like pizza? (Yes, No) • Category scale e.g., please state your gender ( male and female) • Likert scale by Rensis Likert. Designed to examine how strongly respondents agree or disagree with a given statement.
- 27. Validity • Validity: Is the measure, measuring what it supposed to measure. • Validity: Are we measuring the right thing? • Validity: The extent to which a test measures the construct is intended to measure.
- 28. Reliability • Reliability of measure indicates extent to which it is without bias and hence ensures consistent measurement across time (stability) and across the various items in the instrument (internal consistency).
- 29. Descriptive Statistics • Descriptive Statistics are used to describe the basic features of the data in a study including what the data are or what they show. • The Frequency Distribution is a summary of the frequency of individual values or ranges of values for a variable.
- 30. Frequency Distribution
- 31. Histogram • Histogram: also known as a bar graph, uses bars to indicate the frequencies for each value of X (which are placed along the horizontal x-axis). The height of the bars indicates the frequencies (which are on the vertical Y-axis).
- 32. Histogram
- 33. Measures of Central Tendency • There are several common methods to estimate measure of central tendency. • Intended to describe the most average scores in the distribution. • Most common measures are the mean, the median, and the mode.
- 34. Mean • Most commonly used method of describing central tendency. • Arithmetic average of all scores. • Add up all of the values and divide by the number of values. • Example : • 1,2,3,4,5,5, 4, 6,3 • 33/9 • =3.67
- 35. Median • The midpoint of the ordered list of values. • List the values in rank order, then find the point below which one-half of the scores lie. • 4,6,7,2,4,1,8,2 • 1,2, 2,4,4,6,7,8 • 4+4=8 • 8/2= 4
- 36. Mode • The easiest measure to understand since it is determined by inspection rather than computation. • Reports the most frequent score in the variable. • Useful when studying nominal variables. • Not often a useful indicator of central tendency in a distribution. E.g. • Mode: 2,3,6,2,4,2,5,6,4,2,4,5,2 • Mode: 2