ACA Pairs Questions (Question Text Tab)
The Pairs section elicits the conjoint tradeoffs. According to the number of pairs questions (n) you specified to include under Specify ACA Interview Parameters screen, Exercise_Pair1 through Exercise_Pairn are included in your questionnaire.
In each case the respondent is shown two product concepts. The respondent is asked which is preferred, and also to indicate strength of preference. The example below presents concepts differing on only two attributes. Although concepts may be specified on up to five attributes, simple concepts like these present an easy task for the respondent, and are a useful way to begin this section of the interview.
(The rating scale can be defined from 2 to 9 points. We suggest using at least 7 scale points.)
Or Text: You can add a space between the product concepts that is just blank, or a word (such as "OR") if you would like. By default, the text " " is specified, which is a reserved series of letters that tells your browser to print a space character. But you can delete this and type a word such as "OR" instead. If you delete the text altogether from the "Or Text" field, the separating cell is deleted.
Every time the respondent completes a page of pairs question(s), the estimate of the respondent's part-worths is updated. Updating the part-worths improves the quality of subsequent pairs questions. We strongly encourage you to place page breaks often throughout the pairs questions. If you can count on fast load times (respondents will be using fast web connections), we suggest page breaks after each pairs question.
Alternating Colors to Improve Readability
Every other product concept can be given an alternating background color. You do this by specifying ACA Alternating Colors under the ACA Settings dialog.
