Editor’s note: David Ashley is a market research specialist at the U.S. Small Business Administration, Washington, D.C.

“It is a capital mistake to theorize in advance of the facts.” Easy for Sherlock Holmes to say, but then, he never administered a questionnaire. Although writing a good questionnaire takes time, following some guidelines can make the process easier and more productive.

Given that survey rules are seemingly numerous, how can you make sense out of writing an effective questionnaire? Remember, a questionnaire is best developed by first dovetailing your secondary research with primary research. Primary research might include a focus group or interviews. After you have laid the foundation, begin drafting the questions - all the while keeping true to your research design and research objectives set forth at the beginning.

Reviewing the four types of data will position you to maximize the effectiveness of your questions. The proper use of these data types will greatly enhance your analysis and final product. Use nominal (the least sophisticated data), ordinal, interval, and ratio (the most sophisticated data) questions throughout the survey. A cross-section of the four types of data will maximize your data analysis options. Remember that more sophisticated data can be revised down to lower-level level data during the analysis phase - but the reverse is not advisable. The hint here is to use as much higher-end data as appropriate.

Scaling is also an important component of creating an effective questionnaire. When possible you should use similar scaling throughout the questionnaire lest you risk confusing the respondent. Similar scaling facilitates data analysis and makes it easier for the respondent - which in turn generally increases the respondents’ willingness to complete the questionnaire. Although they are useful, be aware that odd-numbered scales might result in a...