What? We psychologists analyze a lot of sum-score data. Even though it’s not the best, we usually use the Gaussian likelihood1 for these analyses. I was recently in a situation were I wanted to model sum-scores from a new questionnaire and there was no good prior research on the distribution of the sum-scores. Like, there wasn’t a single published paper reporting the sample statistics. Crazy, I know… Anyway, I spent some time trying to reason through how I would set a justifiable prior ...
