Advances in online survey design and market research in general have allowed us to expand outside the realm of just asking the right questions. In order to ensure participant engagement, and ultimately higher completion rates, we have to consider the question formats we use in addition to how they are written.
In questionnaire creation we have options. One is to select between a drop-down list, a vertical display or a horizontal display. Each format has its advantages. These formats can be applied to both single and multiple select questions with some minor differences.
Drop down boxes, as shown below; offer some key advantages in questionnaire design. Namely they are space savers. If you have several questions that need to be fit on one page this is a good way to accomplish that goal. The categories used can be randomized in order to minimize order bias. However, one drawback with this format is you cannot ask the respondent to specify an ‘other’ response. Other can be a category, but there is no space to allow for written response. You would have to add a sub-question tied to the ‘other’ category.
List questions, either vertical or horizontal, lay all of the response categories out before the eyes of the respondent. If your list is long this may not be a good option. However the advantage, with the vertical or horizontal formats is you can specify multiple columns (or rows) and offer an ‘other’ category where the respondent can reply with a comment. Categories can be randomized.
Ultimately, the choice of question format lies in the hands of the researcher. You have the option of standardizing on a format or allowing yourself the freedom to use different formats based upon the requirements of the survey page.