rating scales

Rating Scales

Research ScholarZainab Saleem

Scaling Defined

• The term scaling refers to procedures for attempting to determine quantitative measures of subjective and sometimes abstract concepts.

• It is defined as a procedure for the assignment of numbers to a property of objects in order to impart some of the characteristics of numbers to the properties in question.

Rating Scale

Measurement scales that allow a respondent to register the degree (or amount) of a characteristic or attribute possessed by

an object directly on the scale.

Attitude rating scales

Attitude:An enduring disposition to

consistently respond to various aspect of the world, including persons, events and objects

Typically seen as having three components:

Cognitive

Affective

Behavioral

i. Affective

• The feelings or emotions toward an object

ii. Cognitive

• Knowledge and beliefs

iii. Behavioral

Predisposition to action

Intentions

Behavioral expectations

Unidimensional Scaling

Multidimensional Scaling

Procedures designed to

measure only one attribute of a respondent or

object

Procedures designed to measure several dimensions of a respondent or

object

Six main types of rating scales:1. Category scale

2. Semantic differential scale

3. Stapel scale

4. Likert scale (Summated ratings scale)

5. Constant sum scale

6. Graphic scale

1. Category Scale

• A rating scale which the response options provided for a closed-ended question are labeled with specific verbal descriptions.

Example:

Please rate car model A on each of the following dimensions:

Poor Fair Good V.good Excellent

a) Durability [ ] [ ] [ ] [ ] [ ]

(b) Fuel consumption [ ] [ ] [ ] [ ] [ ]

Characteristics

• Response options are still verbal descriptions.

• Response categories are usually ordered according to a particular descriptive or evaluative dimension.

• Therefore scale has ordinal properties.

• However, researchers often assume that it possesses interval properties but this is only an assumption.** One special version is the Simple category scale.

Simple Category Scale • A category scale with only two response

categories (or scale points) both of which are labeled.

Example: Please rate brand A on each of the following dimensions:

poor excellent(a) Durability [ ] [ ]

(b) Fuel consumption [ ] [ ]

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 durable

Low fuel consumption ---:---:---:---:---:-X-:--- High fuel consumption

Characteristics

1. The scale has properties of an interval scale.

2. Sometimes descriptive phrases are used instead of bipolar adjectives, especially when it is difficult to get adjectives that are exact opposites

3. It is often used to construct an image profile.

3. Stapel Scale A simplified version of the semantic differential scale

in which a single adjective or descriptive phrase is used instead of bipolar adjectives.

Example:

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

Characteristics

1. The scale measures both the direction and intensity of the attribute simultaneously.

2. It has properties similar to the semantic differential.

4. 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

Durable 1 2 3 4 5 6 7 Not durable

Numerical Scale• Any rating scale in which numbers rather than semantic

space or verbal descriptions are used as response options.

Examples: Poor Excellent

Durability 1 2 3 4 5 6 7

5. Graphic Ratings Scales

• Rating scales in which respondents rate an object on a graphic continuum, usually a straight line.

• Modified versions are the ladder scale and happy face scale.

Characteristics

1. The straight line scale has ratio level properties.

2. The ladder and happy face scales have properties depending on the labeling option chosen – whether all response categories are labeled (ordinal properties) or only the scale end-points are labeled (interval properties).

6. The Likert 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

Characteristics • The following procedure is used to analyze

data from Likert scales:

1. First, weights are assigned to the responses options, e.g. Totally agree=1, Agree=2, etc

2. Then negatively-worded statements are reverse-coded (or reverse scored). E.g. a score of 2 for a negatively-worded statement with a 5-point response options is equivalent to a score of 4 on an equivalent positive statement.

1. Next, scores are summed across statements to arrive at a total (or summated) score.

2. Each respondent’s score can then be compared with the mean score or the scores of other respondents to determine his level of attitude, loyalty, or other construct that is being measured

• Note that the response for each individual statement is expressed on a category scale.

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

Issues In Selecting A Measurement Scale

1. Whether to use single or index measure.

2. Whether to use a ranking, sorting, choice, or rating scale.

3. Whether to use monadic or comparative scale.• Monadic rating scale is one in which

respondents evaluate an object in isolation• Comparative scale is one in which the object

is evaluated in relation to other objects• Construction and labeling is different for

monadic and comparative scales

4. Whether to use category labels or not.

5. If the decision is to use category labels, what labels to use.

6. Number of response options (scale categories) to use, i.e. whether to use 2, 3, 4, 5, etc response categories• In general, the larger the number of categories

the more sensitive the scale is; but also the more difficult it is for respondents to answer

7. Whether to use balanced or unbalanced scale.• A balanced scale has an equal number of

points to the left and right of a mid-point. An unbalanced scale has more response options on one side than the other

8. Whether the scale should force choice among the response categories, i.e. should the scale contain a “neutral” or “don’t know” category.