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Scaling Methods

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Scaling Methods

Two types of scales Comparative Scales

Compare one object with another Non-comparative scales

Evaluate each object independently

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Comparative Scales

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Comparative scales

Shows relative importance between two objects

Relatively small differences are detected

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1. Paired comparison

Respondent is shown a pair of objects He is asked to select one object that he

prefers

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1. Paired comparison – Example 1

Que.: I will show pair of brands. Please tell me which brand do you prefer from each pair

Brand 1 Brand 2 Preferred

LG Samsung

LG Akai

Akai Sony

Samsung Sony

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1. Paired comparison – Example 1

Preferred LG Samsung Akai SonyLG 0.00 0.20 0.75 0.40

Samsung 0.80 0.00 0.90 0.70

Akai 0.25 0.10 0.00 0.35

Sony 0.60 0.30 0.65 0.00

Total 1.65 0.60 2.30 1.45

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1. Paired comparison – Example 2

Que.: Allocate a total of 11 to brands shown in each pair

Brand

1

Brand

2

Score to brand 1

Score to brand 2

LG Samsung

LG Akai

Akai Sony

Samsung Sony

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1. Paired comparison

Easy to administer. Not suitable if number of pairs is large.

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2. Constant sum scale

Respondents are shown all objects to be compared at one time.

He is asked to allocate points to each object out of total points – say 100.

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2. Constant sum scale - Example

Que.: Below are five attributes that you might consider while buying a 4-wheeler. Please allocate a total of 100 points to them. More the points, more important is the attribute to you. You can allocate 0 point if the attribute is not at all important to you.

Attribute Points

Mileage

Seating capacity

Luggage space

Proximity of dealer

Servicing network

TOTAL 100

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2. Constant sum scale

Data gives relative importance. Information on intensity is obtained. Faster than paired comparison. Data is either in interval scale or ratio scale.

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Noncomparative Scales

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1. Continuous rating scale

Respondent is asked to mark (X) anywhere on a line.

Que.: Please indicate your opinion about work of NGOs by placing (X) at the appropriate location on the line shown below

Unfavourable Favourable

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2. Itemised rating scale

Respondent is asked to select one category.

Que.: Please indicate your opinion about work of NGOs by placing (X) in one of the categories shown below.

Unfavourable Favourable

Extremely Quite Slightly Neither Slightly Quite Extremely

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2. Itemised rating scale

No optimal number of categories. Depends on respondent’s ability to

discriminate among categories. Generally 5 to 9 categories are included. 5 points rating scale is popular. Unbalanced categories when responses are

skewed. Separate category for ‘no opinion’ is

desirable.

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2. Itemised rating scale

5 points 7 points 9 points

Definitely Definitely Definitely

Probably Mostly Very likely

Might or might not Probably Likely

Probably not Might or might not Fairly likely

Definitely not Probably not Might or might not

Can not say Mostly not Fairly unlikely

Definitely not Not likely

Can not say Almost not

Definitely not

Can not say

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2. Graphic itemised rating scale

Respondents are shown pictures

Used for children.