Welcome to the

Presentation on

Scales

Prepared By:Protim MondolId#13262005

▪Scaling:- Assigning numbers to

items

Two things to remember- Choosing proper items - Assigning weights to the

items

Types of Scale:

I. Likert ScaleII. Thurstone ScaleIII.Guttman Scale

Likert Scale

▪ Created by Rensis Likert▪ Interval level variables▪ At least 20 statements▪ Five categories of responses▪ A number is assigned to each type of responses▪ Subjects responses are summed up

Strongly Agree

(5)

Agree

(4)

Undecided

(3)

Disagree

(2)

Strongly

Disagree

(1)It is fun to useIt is simple to useIt is very user friendlyIt does not interrupt other programsIt is not costly

Likert Scale (Cont…)

A software company may construct Likert Scale to find out users attitude towards its software

Likert Scale (Cont…)

▪ Discriminatory Power:-The ability to categorize response

based on categories

Measuring Discriminatory Power:- Calculate mean score of responses of two groups of people given extreme responses

- T-test- Correlation Matrix

Likert Scale (Cont…)

Issues with Likert Scale:

- Uni-dimensional

- Response may be influenced by

previous question

Thurstone Scale

▪ Created by Louis Thurstone▪ Interval level variable▪ 50-300 judges▪ Eleven categories of response▪ Items are retained on the basis

of agreement among judges▪ Use of Inter Quartile Range

1 2 3 4 5 6 7 8 9 10 11 Retain

Statement 01

9 10 15 10 6 0 0 0 0 0 0 Yes

Statement 02

5 7 6 0 3 7 2 4 5 8 3 No

Statement 03

0 0 0 0 0 0 3 7 13 16 11 Yes

Statement 04

3 5 12 13 8 9 0 0 0 0 0 Yes

Statement 05

0 0 3 5 7 8 2 5 9 7 4 No1-8 = Favorable Response9-11= Unfavorable Response

Thurstone Scale (Cont…)

Thurstone Scale (Cont…)

Issues with Thurstone Scale:

- May portray popular beliefs

- Responses may not be objective

Guttman Scale

Created by Louis Guttman▪ Ordinal level variable▪ Statements ordered from general

to specific▪ Dichotomous response

categories▪ Keep items which have a

scalable pattern

Guttman Scale (Cont…)

 Q1) Exercise is good for health.(i) Agree (ii) Disagree

Q2) Regular exercise is good for health.(i) Agree (ii) Disagree

Q3) Having balanced exercise is good for health.

(i) Agree (ii) DisagreeQ4) Swimming & walking are good forms of exercise.

(i) Agree (ii) Disagree

Guttman Scale (Cont…)

Response

Pattern

Structure No. of Responde

nts RetainQ1 Q2 Q3 Q4

A + + + + 31 YesB - + + + 36 YesC - - + + 27 YesD - - - + 23 YesE - - - - 21 YesF + - + + 06 NoG + + - + 04 N0H - - + + 03 No

Guttman Scale (Cont…)

Issues with Guttman Scale:

- Analytical complexity

- No guarantee that items will cover a narrow universe of content.

Thank You