HB analysis for Express Max Diff

Question

I'm conducting a max diff study using SSI Web to generate the max diff design. I will collect data via an external programming/hosting vendor (so I will not be using SSI Web for survey adminstration and data collection). I'm considering using Express Max Diff (described in Wirth and Wolfrath's 2012 paper from the Sawtooth Software Conference) - which for my study will involve about 20 design blocks (each block will consist of about 30 items out of 100 or so total items to be tested) - with each deign block corresponding to a seperate max diff design containing only the the 30 items in the block. I will need to use the paper and pencil method to read the max diff response data back into SSI Web and perform HB estimation.

Is there a resource providng a step-by-step description of how to read the Express Max Diff data into SSI Web (via the paper and pencil data interface) and perform HB analysis to obtain respondent-level max diff scores - where a max diff scores for all 100 items is obtained for each respondent even though they only completed max diff for 30 of the 100 items?

Answer 1

No such luck to get SSI Web to automatically manage this custom type of data as suggested by Wirth.  You'll want to follow Ralph's recommendations, and also look at the paper by Horne also in the 2012 Proceedings for ideas regarding the coding.  Then, you'll want to directly prepare your data in the .csv format and submit it directly to CBC/HB for parameter estimation.  This will require knowledge of how to dummy-code design matrices.

If you get stuck with all this, we do have a consulting group (Sawtooth Analytics) that is willing to do such efforts for a fee.