A survey might ask a question using a ranking scale such as :
Please rate the following products from 1 (most preferred) to 5 (least preferred).
Next, the researcher uses a data reduction technique like factor analysis to obtain aggregate scores. To convert these aggregate rankings into purchase probabilities, each category (in this case, each product) will be weighted with a translation coefficient. These weights are predefined.
A typical weighting scheme is:
first choice = 75%
second choice = 17%
third choice = 6%
fourth choice = 2%
fifth choice = 0%
The weighting schemes vary depending on the variables being measured.
The following chart illustrates the procedure:
score | rank | weight | probability | |
product A | 6.4 | 2nd | .17 | 1.1 |
product B | 5.1 | 4th | .02 | .1 |
product C | 8.7 | 1st | .75 | 6.5 |
product D | 4.3 | 5th | 0 | 0 |
product E | 5.5 | 3rd | .06 | .3 |
Other purchase intention/rating translations include logit analysis and the intent scale translation.
See also : marketing research, New Product Development, marketing, preference regression, quantitative marketing research