I am designing a CBC study in Lighthouse Studio where respondents may show strong loyalty to their current smartphone brand. To properly capture both cross-brand choices and within-brand trade-offs, I am planning a hybrid design where each respondent completes two CBC exercises in a single survey:
A standard CBC block where Brand varies (Apple, Samsung, Xiaomi) along with the other attributes (Battery, Camera, Price).
A second CBC block where Brand is fixed to the respondent’s own current brand (I ask about their current brand in demographic questions), so they must make within-brand trade-offs among Battery, Camera, and Price without simply choosing their preferred brand every time.
To implement this, I created three CBC designs, all using the same attributes and levels:
CBC_FullBrand – Brand varies normally
CBC_AppleOnly – Brand fixed at Apple (via manual design import)
CBC_SamsungOnly – Brand fixed at Samsung (via manual design import)
My intended logic is:
If a respondent’s current phone brand = Apple → show CBC_FullBrand (6 tasks)+ CBC_AppleOnly (6 tasks)
If current brand = Samsung → show CBC_FullBrand (6 tasks) + CBC_SamsungOnly (6 tasks)
Otherwise → show CBC_FullBrand (6 tasks)+ CBC_FullBrand_2 (6 tasks)(a second version of the full CBC to keep all respondents exposed to an equal number of tasks)
My questions are:
In my version of Lighthouse Studio, I cannot find a “Show Question If” option directly on CBC questions. What is the recommended way to conditionally show specific CBC exercises based on respondents’ answers?
Because all three CBCs share identical attributes and levels, but Brand is fixed in some designs, I would like to aggregate all tasks across all CBC blocks and estimate one combined HB model and one combined Latent Class model, not three separate models. But I cannot find this option in the analysis part of Lighthouse Studio.