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Treat two levels of attribute as one level

Dear team,

we are to set up a CBC with 6 attributes where respondents should choose among different commercial transaction partners which are described by a set of different attributes. One attribute (which we label "photo included") should contain two levels:

1. No photo included (here a silhouette of a profile picture is shown)
2. Photo included

We plan to have a CBC with 10 choice tasks showing 3 choice options each. Now we face the following problem:

If we choose one photo for level 2 (Photo included), in some choice tasks, the same photo of the person is shown twice, but then in combination with other levels. This might confuse people, when one photo of a person is shown with the information that this person e.g. lives 5 km away, whereas the same photo is shown with the information that this person lives 20 km away.

We wonder whether one solution to prevent this situation would be to generate three levels of the attribute ("photo included"):

1. No photo included (here a silhouette of a profile picture is shown)
2. Photo included (Version 1)
3. Photo included (Version 2)

We would try to find two pictures of women that are rated similar in terms of attractiveness, etc.

Would it be possible to treat attribute level 2 (version 1) and 3 (version 2) than as the same attribute level. We were thinking to change the design file of the CBC ex-post (by treating level 3 as level 2) and use this altered design file for the HB analysis then.

Do you think that approach could be feasible?
asked Feb 10 by Stefanie

1 Answer

0 votes
Yes, you can recode the two levels to be the same level during estimation and subsequent market simulations.  Feasible and seems appropriate.
answered Feb 10 by Bryan Orme Platinum Sawtooth Software, Inc. (129,940 points)
Recoding 2-levels into 1-level (for ACA)
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