No matter how experienced you are in developing questionnaires or how "routine" the survey might be considered, it is always important to pretest your instrument before it is printed and fielded. Start by reading it aloud – the flow of words should sound conversational/read smoothly and communicate clearly. Instructions should not leave any doubt about what the respondent is supposed to do. Check each question carefully to ensure that it will indeed provide the information you need, and that the meaning of every word is clear. Go back and revise your survey!

Next, give the questionnaire to a small group of people, who preferably know little or nothing about the research itself. Ask them to read the questionnaire to see if they, too, can clearly understand what is required and whether the flow makes sense to them. Go back and revise your survey!

And finally, select a small number of people from your sampling frame, if at all possible, and test your questionnaire with them (even if your questionnaire turns out to be "pretty good", you should not include these respondents in your final sample). Look at the frequency distribution: if there are too many "neutral", "don’t know" or "don’t remember" responses, you need to revise the questions themselves. If the questions that require a written response look too "squished", provide more generous spacing.

You should ask the respondents to also comment on the questionnaire itself, and on whether you should perhaps be asking some additional questions relevant to the research problem as stated in the introduction. Since people are often reluctant to admit that they might have difficulty responding, ask them whether they believe other people would have difficulty and which questions in particular might pose problems? You will elicit many useful comments, so: Go back and revise your survey!

And remember that you will have to go through the same steps for each language used for the survey, and that you will need to check for cultural and regional differences as well in these cases.

Pamela Narins, the Market Research Manager for SPSS, has provided "13 important tips to help you pretest your surveys" that you should definitely check out!