Comparative Rating Scale

COMPARATIVE RATING SCALE A type of scale, which requires the respondents to make their ratings as a series of relative judgments or comparisons with a benchmark—perhaps another similar concept such as a comparative brand— explicitly used as a frame of reference. In many cases the comparative rating scale presents “the ideal situation” as a reference point for comparison with the actual situation. For example, please indicate amount of space in your present car that compares with the amount of space you feel should be in an ideal car. First type of comparative scaling is paired comparison scale. Paired Comparison Scale A paired comparative scale is a technique in which respondent is presented with two objects at a time in the pair and asked to select one according to some criterion. It is like an ordinal scale in which two objects are ranked. Let us see the example. We are presenting you with ten pairs of shampoo brands. Please indicate which one you like for your use.

In the above table, we see that figure 1 in the box means that column brand is preferred to corresponding brand in row and a zero in the box means that brand in row is preferred to the corresponding column. Rank Order Scale: This scale is also comparative in nature. It involves asking the respondents to rank various brands/objects with regard to some criterion. For example a respondent may be asked to rank five print ads on the basis of awareness, it provides, liking of the respondent or intention to buy. Look at the following data. An Example of Rank-Order Scale Please rank the following brands of fruit juices in order of preference from 1 to 7.rate your most preferred brand as 1 and least preferred brand 7; all others are in between No. 2 brands will receive the same rating. There is no right or wrong answer: it is just matter of preference. Brand A B C

Preference order 2 6 4

D E F G

1 7 5 3

This technique is frequently used in marketing research. Advantages of rank-order scaling include that it is simple concept, easy to administer and less time consuming to administer than other comparative scale such as paired comparison. The instructions for ranking objects are easy to comprehend. It is also said that the ranking made by the respondent is closer to his/her real purchase situation. The major disadvantage of rank order scale is that it produces only ordinal data. It does not mean that first preference in the set is the most liked. It may be “least disliked” in the set. Constant-Sum Scale: In constant-sum scale respondents are required to allocate a fixed number of rating point (usually 100) among several objects. It is widely used to measure the relative importance of various attributes of the object. See the following example. Please divide 100 points among the following characteristics of a tooth paste that reflects the relative importance of each characteristic to you in the selection of toothpaste. It an attribute is unimportant to you, assign zero.

Taste _____________8_________ Fragrance _____________7_________ Tube _____________5_________ Cleanliness of teeth _____________35________ Prevention of tooth decay ____________25________ Price _____________2_________ Quality _____________8_________ Shining of the teeth _____________10________ Total 100 _______

The relative importance of the attributes is determined by the counting the points assigned by all respondents and dividing by the number of respondents. The main merit of the constant sum scale is that it permits fine distinction of attributes of an object without much time. However it may be difficult to allocate points to several categories. The main disadvantage of this scale is that respondents may allocate points that exceeds or are short of the required total say 103o or 97o instead of 100.