Types of scales

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Types of Scales

• Likert/Summated Rating Scales• Semantic Differential Scales• Magnitude Scaling• Thruston Scales• Guttman Scales

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Likert Scales

• A very popular rating scale• Measures the feelings/degree of agreement of

the respondents• Ideally, 4 to 7 points• Examples of 5-point surveys

– Agreement SD D ND/NA A SA– Satisfaction SD D ND/NS S SS– Quality VP P Average G VG

The Likert Scale (Summated Ratings Scale)

A multiple item rating scale in which the degree of an attribute possessed by an object is determined by asking respondents to agree or disagree with a

series of positive and/or negative statements describing the object.

Example:

Totally disagree Disagree Neutral Agree

Totally agree

a) Shopping takes much longer on the Internet [ ] [ ] [ ] [ ] [ ]b) It is a good thing that Saudi consumers have the opportunity to buy products through the [ ] [ ] [ ] [ ] [ ]c) Buying products over the Internet is not a sensible thing to do [ ] [ ] [ ] [ ] [ ]

Attitude toward buying from the Internet

Likert

Strongly Agree

Agree

Neither Agree or Disagree

Disagree

Strongly Disagree

1 2 3 4 5 6 7

Circle the number that best represents your agreement or disagreement with this statement

I always recycle paper, plastic, glass items.

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Summative Ratings

• A number of items collectively measure one construct (Job Satisfaction)

• A number of items collectively measure a dimension of a construct and a collection of dimensions will measure the construct (Self-esteem)

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Summative Likert Scales

• Must contain multiple items• Each individual item must measure something

that has an underlying, quantitative measurement continuum

• There can be no right/wrong answers as opposed to multiple-choice questions

• Items must be statements to which the respondent assigns a rating

• Cannot be used to measure knowledge or ability, but familiarity

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Semantic Differential Scales

• Uses a set of scale anchored by their extreme responses using words of opposite meaning.

• Example:Dark ___ ___ ___ ___ ___ LightShort ___ ___ ___ ___ ___ TallEvil ___ ___ ___ ___ ___ Good

• Four to seven categories are ideal

Semantic Differential Scale

• A rating scale in which bipolar adjectives are placed at both ends (or poles) of the scale, and response options are expressed as “semantic” space.

Example: Please rate car model A on each of the following dimensions:Durable ---:-X-:---:---:---:---:--- Not durableLow fuel consumption ---:---:---:---:---:-X-:--- High fuel consumption

Semantic Differential

Boring

My responsibility

Necessary for thepreservation of earth

Does little to helpthe environment

Exciting

Not myresponsibility

Not necessary for the preservation of earth

Does a great deal to help the environment

Recycling is ...

Please check the blank that best describes the phrase below. The closer you believe the word or word phrase relates, the you would place your check nearer to the word/word phrase.

Noncomparative Rating Scales

Overall, how would you rate your level of recycling? Please check the appropriate response.

Exceptionally ExceptionallyPoor Good

Noncomparative Rating Scales

Overall, how would your level of recycling. Please place a check mark along the line that best represents your rating.

Exceptionally ExceptionallyPoor Good

Non Comparative Rating Scales

Overall, how would you rate your level of recycling? Please circle the appropriate response.

Exceptionally Exceptionally

Poor Good 1 2 3 4 5 6 7

Comparative Rating Scales

Overall, how would you rate your level of recycling compared to other college students? Please circle the appropriate response.

Exceptionally Exceptionally Poor Good

1 2 3 4 5 6 7

Stapel Scale • A simplified version of the semantic differential scale in which a single

adjective or descriptive phrase is used instead of bipolar adjectives.

Characteristics1. The scale measures both the direction and intensity of the attribute

simultaneously.2. It has properties similar to the semantic differential.

Example:

Model A-3 -2 -1 Durable Car 1 2 3-3 -2 -1 Good Fuel Conaumption 1 2 3

Constant-Sum Scale • A rating scale in which respondents divide a constant sum among

different attributes of an object (usually to indicate the relative importance of each attribute).

• Assumed to have ratio level properties.

Example: Divide 100 points among the following dimensions to indicate their level of importance to you when you purchase a car:

Durability Fuel Consumption Total 100

Thurstone scale

• Thurstone's Law of Comparative Judgment is presented as an alternative means to derive metric values for subjective health outcomes. The appeal of Thurstone's scaling model is that it can transform subjective individual rank order data or comparative preference data to a single group composite interval scale.

steps

• Generate large no: of statements, relating to the attitude to be measured

• Statements are given to group of judges to classify them

• 11 piles to made by the judges• Study the frequency distribution of rating for each

statement• Eliminate those statement have widely scattered ratings• Select 1 or 23 statement from each pile, list them in

random order to form the scale

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Thurston Scales

• Thurston Scales– Items are formed– Panel of experts assigns values from 1 to 11 to

each item– Mean or median scores are calculated for each

item– Select statements evenly spread across the scale

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Thurston Scales

• Example:Please check the item that best describes your level

of willingness to try new tasks– I seldom feel willing to take on new tasks (1.7)– I will occasionally try new tasks (3.6)– I look forward to new tasks (6.9)– I am excited to try new tasks (9.8)

Hard to attach a verbal explanation to response

Visual impact, easy for poor readers

Choose a visual picture 8. Graphic scale-picture response

No standard answers Visual impact, unlimited scale points

Choose a point on a continuum

7. Graphic scale

Endpoints are numerical, not verbal.

Easier to construct than semantic differential

Choose point on scale with 1 center adjective

6. Stapel scale

Difficult for respondents with low education levels

Scale approximates an interval measure

Divide a construct sum among response alternatives

5. Constant sum scale

Bipolar adjectives must be found, data may be ordinal, not interval

Easy to construct, norms exist for comparison, e.g. profile analysis

Choose points between bipolar adjectives on relative dimensions

4. Semantic differential and numerical scales

Hard to judge what a single score means

Easiest scale to construct Evaluate statements on a 5-point scale

3. Likert scale

Ambiguous items, few categories, only gross distinction.

Flexible, easy to respond Indicate a response category

2.Category scale

1. Simple attitude scaling

Disadvantages Advantages Subject must:Rating Scale

Characteristics Different Types of Rating Scales