I plan on building 3 holdout choice tasks on top of my CVA scenarios.
I have three questions.
First, in terms of a better design of holdout sets, would ratings-based holdout questions identical to other CVA scenarios be better than holdout choice tasks in grid type with three columns? Or is it purely a preference of a researcher?
Second, upon reading the technical papers and other postings about holdout sets, it stated that "Attribute level not repeated within a task".
I have two attributes, both only have two levels.
In building three columns/choices within a holdout set, is it better to include two predicted to be preferred levels and one less preferred level?
Third, if I understood correct, the good holdout sets may be built with some kind of idea of respondents' preferences.
Does this imply that the relevant academic literature along with the news articles can be the reference point in building the holdout tasks? Or, possibly using the simulation results by collecting 50 samples (similar to the example provided in the technical paper) and combine the ranked products possible with 50/30/20% shares?
Thanks for your answers in advance.