200 chapter 7 measurement :scaling by uma sekaran
TRANSCRIPT
![Page 1: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/1.jpg)
1
Measurement: Scaling, Reliability, Validity
CHAPTER 7
![Page 2: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/2.jpg)
2
Chapter Objectives Know the characteristics and power of
the four types of scales- nominal, ordinal, interval, and ratio.
Know how and when to use the different forms of rating scales and ranking scales.
Explain stability and consistency and how they are established.
Discuss what “goodness” of measures means, and why it is necessary to establish it in research.
![Page 3: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/3.jpg)
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.
3
![Page 4: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/4.jpg)
scales There are four basic types of
scales:1. Nominal Scale2. Ordinal Scale3. Interval Scale4. Ratio Scale
4
![Page 5: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/5.jpg)
scales The degree of sophistication to
which the scales are fine-tuned increases progressively as we move from the nominal to the ratio scale.
The information on the variables can be obtained in greater detail when we employ an interval or a ratio scale than the other two scales.
5
![Page 6: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/6.jpg)
scales With more powerful scales,
increasingly sophisticated data analyses can be performed, which in turn, means that more meaningful answers can be found to our research questions.
6
![Page 7: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/7.jpg)
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 MaleO Female
7
![Page 8: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/8.jpg)
Nominal Scale For example, the variable of
gender, respondents can be grouped into two categories- male and female.
Notice that there are no third category into which respondents would normally fall.
8
![Page 9: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/9.jpg)
Nominal Scale The information that can be
generated from nominal scaling is to calculate the percentage (or frequency) of males and females in our sample of respondents.
9
![Page 10: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/10.jpg)
Example 1 Nominally scale the nationality of individuals in
a group of tourists to a country during a certain year.
We could nominally scale this variable in the following mutually exclusive and collectively exhaustive categories.
American Japanese Russian Malaysian Chinese German Arabian Other
10
![Page 11: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/11.jpg)
Example 1 Note that every respondent has to
fit into one of the above categories and that the scale will allow computation of the numbers and percentages of respondents that fit into them.
11
![Page 12: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/12.jpg)
Ordinal Scale 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 completed?O Less than High School O High School/GED Equivalent O College Degree O Masters Degree O Doctoral Degree
12
![Page 13: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/13.jpg)
Ordinal Scale The preference would be ranked
( from best to worse; or from first to last) and numbered as 1, 2, 3, and so on.
13
![Page 14: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/14.jpg)
Example 2 Rank the following five
characteristics in a job in terms of how important they are for you.
You should rank the most important item as 1, the next in importance a 2, and so on, until you have ranked each of them 1, 2, 3, 4, or 5.
14
![Page 15: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/15.jpg)
Example 2 (Cont.) Job Characteristic
Ranking The opportunity provided by the job to: 1. Interacts with others _____ 2. Use different skills _____ 3. Complete a task to the end _____ 4. Serve others _____ 5. Work independently _____
15
![Page 16: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/16.jpg)
Example 2 (Cont.) This scale helps the researcher to
determine the percentage of respondents who consider interaction with others as most important, those who consider using a number of skills as most important, and so on. Such knowledge might help in designing jobs that would be seen as most enriched by the majority of the employees.
16
![Page 17: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/17.jpg)
Example 2 (Cont.) We can see that the ordinal scale
provides more information than the nominal scale. Even though differences in the ranking of objects, persons are clearly known, we do not know their magnitude.
This deficiency is overcome by interval scaling.
17
![Page 18: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/18.jpg)
18
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.
![Page 19: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/19.jpg)
Interval scale
19 ©2009 John Wiley & Sons Ltd.
www.wileyeurope.com/college/sekaran
![Page 20: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/20.jpg)
Example 3a Indicate the extent to which you
agree with the following statements as they relate to your job, by circling the appropriate number against each, using the scale given below.
strongly disagree 1, Disagree 2 Neither Agree Nor Disagree 3 Agree 4, Strongly Agree 5.
20
![Page 21: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/21.jpg)
Example 3a (Cont.) The following opportunities offered
by the job are very important to me:
21
Interacting with others
12345
Using a number of different skills
12345
Completing a task from beginning to end
12345
Serving others12345
Working independently
12345
![Page 22: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/22.jpg)
Example 3a (Cont.) Suppose that the employees circle the
numbers 3, 1, 2, 4, and 5 for the five items. The magnitude of difference represented
by the space between points 1 and 2 on the scale is the same as the magnitude of difference represented by the space between points 4 and 5, or between any other two points. Any number can be added to or subtracted from the numbers on the scale, still retaining the magnitude of the difference.
22
![Page 23: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/23.jpg)
Example 3a (Cont.) If we add 6 to the five points on the
scale, the interval scale will have the numbers 7, 8,….., 11 ( instead of 1 to 5).
The magnitude of the difference between 7 and 8 is still the same as the magnitude of the difference between 9 and 10. It has an arbitrary origin.
23
![Page 24: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/24.jpg)
2424
Example 3b
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 disagree completely 1 2 3 4 5 I agree completely
2. I exert myself too much considering what I get back in return
I disagree completely 1 2 3 4 5 I agree completely
3. For the efforts I put into the organization, I get much in return
I disagree completely 1 2 3 4 5 I agree completely
![Page 25: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/25.jpg)
Ratio Scale Ratio scale: overcomes the
disadvantage of the arbitrary origin point of the interval scale, in that it has an absolute (in contrast to an arbitrary) zero point, which is a meaningful measurement point.
What is your age?
26
![Page 26: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/26.jpg)
Ratio Scale
26
![Page 27: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/27.jpg)
Ratio Scale The ratio scale is the most
powerful of the four scales because it has a unique zero origin ( not an arbitrary origin).
The differences between scales are summarized in the next Figure.
27
![Page 28: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/28.jpg)
The differences between scales
28
![Page 29: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/29.jpg)
Properties of the Four Scales
![Page 30: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/30.jpg)
30
Developing Scales The four types of scales that can be used
to measure the operationally defined dimensions and elements of a variable are:
Nominal, Ordinal, Interval, and Ratio scales.
It is necessary to examine the methods of scaling (assigning numbers or symbols) to elicit the attitudinal responses of subjects toward objects, events, or persons.
![Page 31: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/31.jpg)
31
Developing Scales Categories of attitudinal
scales: (not to be confused with the four different types of scales)
The Rating Scales The Ranking Scales
![Page 32: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/32.jpg)
32
Developing Scales Rating scales have several
response categories and are used to elicit responses with regard to the object, event, or person studied.
Ranking scales, make comparisons between or among objects, events, or persons and elicit the preferred choices and ranking among them.
![Page 33: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/33.jpg)
33
Rating Scales The following rating scales are
often used in organizational research.
1. Dichotomous scale2. Category scale3. Likert scale4. Numerical scale
![Page 34: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/34.jpg)
34
Rating Scales5. Semantic differential scale6. Itemized rating scale7. Fixed or constant sum rating scale8. Stapel scale9. Graphic rating scale10. Consensus scale
![Page 35: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/35.jpg)
35
Dichotomous Scale Is used to elicit a Yes or No
answer. (Note that a nominal scale is
used to elicit the response) Example 4 Do you own a car? Yes No
![Page 36: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/36.jpg)
36
Category Scale It uses multiple items to elicit a single
response. Example 5 Where in Jordan do you reside? Amman Mafraq Irbid Zarqa Other
![Page 37: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/37.jpg)
37
Likert Scale Is designed to examine how strongly
subjects agree or disagree with statements on a 5-point scale as following:
_________________________________Strongly Neither Agree StronglyDisagree Disagree Nor Disagree Agree Agree 1 2 3 4 5______________________________________________________
![Page 38: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/38.jpg)
38
Likert Scale This is an Interval scale and the
differences in responses between any two points on the scale remain the same.
![Page 39: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/39.jpg)
39
Semantic Differential Scale We use this scale when several
attributes are identified at the extremes of the scale. For instance, the scale would employ such terms as: Good – Bad
Strong – Weak Hot – Cold
![Page 40: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/40.jpg)
40
Semantic Differential Scale This scale is treated as an Interval
scale. Example 6
What is your opinion on your supervisor? Responsive--------------Unresponsive Beautiful-----------------Ugly Courageous-------------Timid
![Page 41: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/41.jpg)
41
Numerical Scale Is similar to the semantic differential
scale, with the difference that numbers on a 5- points or 7-points scale are provided, as illustrated in the following example:
How pleased are you with your new job? Extremely Extremlely pleased 5 4 3 2 1 displeased
![Page 42: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/42.jpg)
42
Itemized Rating Scale A 5-point or 7-point scale is provided for each
item and the respondent states the appropriate number on the side of each item. This uses an Interval Scale.
Example 7(i) Respond to each item using the scale below, and indicate
your response number on the line by each item. 1 2 3 4 5Very unlikely unlikely neither likely very likely unlikely nor likely-------------------------------------------------------------------------------- I will be changing my job in the near future. --------
![Page 43: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/43.jpg)
43
Itemized Rating Scale Note that the above is balanced
rating with a neutral point. The unbalance rating scale
which does not have a neutral point, will be presented in the following example.
![Page 44: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/44.jpg)
44
Itemized Rating Scale Example 7(ii) Circle the number that is closest to how
you feel for the item below: Not at all Somewhat Moderately Very much interested interested interested interested 1 2 3 4--------------------------------------------------------------------------------How would you rate your interest 1 2 3 4In changing current organizational Policies?
![Page 45: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/45.jpg)
45
Fixed or Constant Sum Scale The respondents are asked to distribute a
given number of points across various items.
Example : In choosing a toilet soap, indicate the importance you attach to each of the following five aspects by allotting points for each to total 100 in all.
Fragrance ----- Color ----- Shape ----- Size ----- _________ Total points 100This is more in the nature of an ordinal scale.
![Page 46: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/46.jpg)
46
Stapel Scale This scale simultaneously measures
both the direction and intensity of the attitude toward the items under study. The characteristic of interest to the study is placed at the center and a numerical scale ranging, say from +3 to – 3, on either side of the item as illustrated in the following example:
![Page 47: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/47.jpg)
47
Example 8: Stapel Scale State how you would rate your supervisor’s abilities with
respect to each of the characteristics mentioned below, by circling the appropriate number.
+3 +3 +3 +2 +2 +2 +1 +1 +1 Adopting modern Product Interpersonal Technology Innovation Skills - 1 - 1 - 1 - 2 - 2 - 2 - 3 - 3 - 3
![Page 48: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/48.jpg)
48
Graphic Rating Scale A graphical representation helps
the respondents to indicate on this scale their answers to a particular question by placing a mark at the appropriate point on the line, as in the following example:
![Page 49: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/49.jpg)
49
Graphic Rating Scale Example 9 On a scale of 1 to 10, how would
you rate your supervisor?
5
1
10
![Page 50: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/50.jpg)
50
Ranking Scales Are used to tap preferences
between two or among more objects or items (ordinal in nature). However, such ranking may not give definitive clues to some of the answers sought.
![Page 51: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/51.jpg)
51
Ranking Scales Example 10 There are 4 product lines, the manager seeks
information that would help decide which product line should get the most attention.
Assume: 35% of respondents choose the 1st product.
25% of respondents choose the 2nd product. 20% of respondents choose the 3rd product. 20% of respondents choose the 4th product. 100%
![Page 52: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/52.jpg)
52
Ranking Scales The manager cannot conclude that the
first product is the most preferred. Why? Because 65% of respondents did not
choose that product. We have to use alternative methods like Forced Choice, Paired Comparisons, and the Comparative Scale.
We will describe the Forced Choice as an example.
![Page 53: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/53.jpg)
53
Forced Choice The forced choice enables
respondents to rank objects relative to one another, among the alternative provided. This is easier for the respondents, particularly if the number of choice to be ranked is limited in number.
![Page 54: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/54.jpg)
54
Forced Choice Example 11 Rank the following newspapers that you
would like to subscribe to in the order of preference, assigning 1 for the most preferred choice and 5 for the least preferred.
الدستور-------•الرأي---------••---- اليوم أخبارالغد-----------• شيحان--------•
![Page 55: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/55.jpg)
55
Goodness of Measures
It is important to make sure that the instrument that we develop to measure a particular concept is accurately measuring the variable, and we are actually measured the concept that we set out to measure.
![Page 56: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/56.jpg)
56
Goodness of Measures We need to assess the goodness
of the measures developed. That is, we need to be reasonably sure that the instruments we use in our research do indeed measure the variables they are supposed to, and that they measure them accurately.
![Page 57: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/57.jpg)
Goodness of Measures
![Page 58: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/58.jpg)
58
Goodness of Measures How can we ensure that the
measures developed are reasonably good?
First an item analysis of the responses to the questions tapping the variable is done.
Then the reliability and validity of the measures are established.
![Page 59: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/59.jpg)
59
Item Analysis Item analysis is done to see if the items in
the instrument belong there or not. Each item is examined for its ability to discriminate between those subjects whose total scores are high, and those with low scores.
In item analysis, the means between the high-score group and the low-score group are tested to detect significant differences through the t-values.
![Page 60: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/60.jpg)
60
Item Analysis The items with a high t-value are
then included in the instrument. Thereafter, tests for the reliability of the instrument are done and the validity of the measure is established.
![Page 61: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/61.jpg)
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).
66
![Page 62: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/62.jpg)
62
Stability
Stability: ability of a measure to remain the same over time, despite uncontrollable testing conditions or the state of the respondents themselves. Test–Retest Reliability: The
reliability coefficient obtained with a repetition of the same measure on a second occasion.
Parallel-Form Reliability: Responses on two comparable sets of measures tapping the same construct are highly correlated.
84
![Page 63: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/63.jpg)
63
Test-Retest Reliability When a questionnaire containing some
items that are supposed to measure a concept is administered to a set of respondents now, and again to the same respondents, say several weeks to 6 months later, then the correlation between the scores obtained is called the test-retest coefficient.
The higher the coefficient is, the better the test-retest reliability, and consequently, the stability of the measure across time.
![Page 64: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/64.jpg)
64
Parallel-Form Reliability When responses on two comparable
sets of measures tapping the same construct are highly correlated, we have parallel-form reliability.
Both forms have similar items and the same response format, the only changes being the wording and the order or sequence of the questions.
![Page 65: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/65.jpg)
65
Parallel-Form Reliability What we try to establish in the parallel-
form is the error variability resulting from wording and ordering of the questions.
If two such comparable forms are highly correlated (say 8 and above), we may be fairly certain that the measures are reasonably reliable, with minimal error variance caused by wording, ordering, or other factors.
![Page 66: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/66.jpg)
72
Internal Consistency
Internal Consistency of Measures is indicative of the homogeneity of the items in the measure that tap the construct. Inter-item Consistency Reliability: This is
a test of the consistency of respondents’ answers to all the items in a measure. The most popular test of inter-item consistency reliability is the Cronbach’s coefficient alpha.
Split-Half Reliability: Split-half reliability reflects the correlations between two halves of an instrument.
![Page 67: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/67.jpg)
67
Validity Validity tests show how well an
instrument that is developed measures the particular concept it is intended to measure. Validity is concerned with whether we measure the right concept.
Several types of validity tests are used to test the goodness of measures: content validity, criterion-related validity, and construct validity.
![Page 68: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/68.jpg)
68
Content Validity Content validity ensures that the measure
includes an adequate and representative set of items that tap the concept.
The more the scale items represent the domain of the concept being measured, the greater the content validity.
In other words, content validity is a function of how well the dimensions and elements of a concept have been delineated.
![Page 69: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/69.jpg)
69
Criterion-Related Validity Criterion-Related Validity is established
when the measure differentiates individuals on a criterion it is expected to predict. This can be done by establishing what is called concurrent validity or predictive validity.
Concurrent validity is established when the scale discriminates individuals who are known to be different; that is, they should score differently on the instrument as in the following example.
![Page 70: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/70.jpg)
70
Criterion-Related Validity Example 12 If a measure of work ethic is
developed and administered to a group of welfare recipients, the scale should differentiate those who are enthusiastic about accepting a job and glad of a opportunity to be off welfare, from those who would not want to work even when offered a job.
![Page 71: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/71.jpg)
71
Example 12 (Cont.) Those with high work ethic values would
not want to be on welfare and would ask for employment. Those who are low on work ethic values, might exploit the opportunity to survive on welfare for as long as possible.
If both types of individuals have the same score on the work ethic scale, then the test would not be a measure of work ethic, but of something else.
![Page 72: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/72.jpg)
72
Construct Validity Construct Validity testifies to how well the results
obtained from the use of the measure fit the theories around which the test is designed. This is assessed through convergent and discriminant validity.
Convergent validity is established when the scores obtained with two different instruments measuring the same concept are highly correlated.
Discriminant validity is established when, based on theory, two variables are predicted to be uncorrelated, and the scores obtained by measuring them are indeed empirically found to be so.
![Page 73: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/73.jpg)
73
Goodness of Measures Goodness of Measures is established
through the different kinds of validity and reliability.
The results of any research can only be as good as the measures that tap the concepts in the theoretical framework.
Table 7.2 summarizes the kinds of validity discussed in the lecture.
![Page 74: 200 chapter 7 measurement :scaling by uma sekaran](https://reader033.vdocuments.site/reader033/viewer/2022061313/58f330951a28abf6488b4607/html5/thumbnails/74.jpg)
74
Validity
.