What issues should I consider when writing vignettes?

  1. Vignettes should be written so that people in different cultures understand them as similarly as possible. Translation is of course essential, as is cognitive debriefing during pretests.
  2. We find that concrete vignettes that describe specific people and situations are best able to provide constant anchors, although this will not always apply.
  3. Each set of vignettes corresponding to a single self-assessment question should tap a single unidimensional concept. The process of writing vignettes is like the process of testing a theory, in that data (or the examples in the vignettes) tend to focus the mind. As such, the process of writing vignettes tends to have important effects on the concepts themselves. New dimensions are discovered, and the features corresponding to them peeled off, making the original set of vignettes more concrete. And of course sometimes new vignettes and a new self-assessment question are added to measure the new dimension.
  4. Be careful of the details. Sex, age, and other variables can enter the vignettes by something as simple as the name used or other references. Ask whether these other variables are providing the needed contextual detail for the respondent, in which case they should be retained, or whether they are adding additional unintended dimensions that could confuse the respondent or the analyst.
  5. Ideally, only information that is an integral part of the concept being measured should be part of the vignette description. Everything else should be kept implicitly the same as the respondent (so that DIF remains the same for the self-assessment and the vignette questions).