Hierarchical Questions Enable Respondents To Choose from Thousands of Choices
Posted by Jeffrey Henning on Wed, Mar 18, 2009
When writing a questionnaire, sometimes you have thousands of choices that you want a respondent to choose from: the make and model of a car, the brand and name of a specific product, the state and county a respondent lives in. Showing the respondent a list of all the choices would be impractical. You could provide the respondent an open-ended question, but then you would have hundreds, thousands or even tens of thousands of responses to read through and categorize. (For my first job in market research, I would sometimes get called on to code such lists of responses: as time-consuming and tedious a task as you can imagine.)
A better alternative is to present the user a hierarchical question (click image for a working demo):

The choices are arranged in an outline, but the respondent only sees the first-level choices, and then only the second-level choices of the chosen first level. (This can be repeated for three levels: for instance, make, model and year of car.)
While creating and maintaining the outline of possible choices becomes an ongoing chore, it takes less effort than building such an outline from respondents' choices. And it makes for a much better experience for respondents.