100 questions would be a lot, yes, unless you had very large samples, which isn't unheard of in today's age. I suspect it would work better to combine the item

100 questions would be a lot, yes, unless you had very large samples, which isn't unheard of in today's age. I suspect it would work better to combine the items somehow. Alternatively, you might be able to somehow use a subset of the 100 as a kind of anchor, to see how distorted a differently designed sample was, and possibly reweight things. For example, if you were really serious, you might be able to identify, say, 5-10 items with a lot of variance in the population, and ask about them using list randomization, and also maybe directly to determine how people endorse the items differently if asked indirectly versus directly. Depending on what you did with that, you could then use those items as weighting variables for the other 90-95 items in another sample. In the very least you'd be able to compare the samples to see how different the distributions are on the anchor items.