Scales in Survey Questionnaires
Scales are commonly used to rate the satisfaction or importance of products, services and attributes. They are also used to determine the level of agreement with statements. Scales can either be numeric, for example “How important to you are each of the following on a scale of 1 to 10, where 10 means extremely important and 1 means not at all important?” or labeled, for example “Was our service excellent, good, fair or poor?”
Any survey questionnaire software will let you ask scale questions as a series of multiple-choice questions. Most software will also let you ask for ratings or agreement with a series of related items in a grid or matrix format. Some software, such as The Survey System, also offers the option of using sliders for ratings.
Which format works best often depends on the details of the questions and on the devices people will use to answer your questions. Questions with labeled choices are often presented as a grid for web surveys and telephone interviewing, but grids are often too wide for people taking surveys on smartphones. Survey questionnaire software that uses responsive web design may be able to show scale questions as grids on PCs and as a series of multiple-choice questions on smartphones and/or tablets. If you are asking for ratings of or agreement with concepts that take more than a sentence to describe, you should almost always use a series of multiple-choice questions.
Answers to numeric scales can also be collected in grids or multiple-choice questions, as well as a couple of other ways. Sliders can be an engaging way to get numeric ratings, but might not work on smartphones, because the phones may interpret attempts to drag the slider as attempts to scroll the window. Another choice for numeric scales is a text box next to each item in which people enter their chosen number.
The results of scale questions can be presented in a variety of ways, depending on the types of analysis desired. These will be the subject of a future blog post.