Caroline makes some very good points. Questionnaire design is complex and there are hundreds of articles debating the use of mid-points, the meaning of a mid-point, and other topics like how the order of questions influences answers. For many surveys, a Don't Know, Don't Care, or I Don't want to Answer (say to salary surveys or personal information) are all items that should be considered. If you are writing a questionnaire for a survey on a topic that you don't know well, doing some research beforehand to create the response categories is quite important so you don't have a lot of answers to your "Other" response category.
There are several excellent books that delve into the issues of bias and the many design issue that you need to consider. I would recommend: Robson, C. (2002). Real-world research (Second edition). Malden, MA: Blackwell Publishing. This book describes many methods for gathering data including an excellent section on scale and questionnaire design. The book has a short, but excellent description, for example about how to develop Likert items. Sudman, S., Bradburn, N. M., & Schwarz, N. (1996). Thinking about answers: The application of cognitive processes to survey methodology. San Francisco, CA: Jossey-Bass. Thinking About Answers explores cognitive issues associated with survey methods. These issues include: context effects in surveys, order effects, event dating, counting and estimation, and autobiographical memory. The final chapter summarizes implications of cognitive research for survey design, administration, and interpretation. Dillman, D. A. (2007). Mail and internet surveys: The tailored design method 2007 update with new internet, visual, and mixed-mode guide. New York, NY: Wiley. This book is the third by Dillman who has written the most general book of survey guidelines. Aiken, L. R. (2002). Attitudes and Related Psychosocial Constructs: Theories, assessment, and research. Thousands Oaks, CA: Sage Publications. There are many books in social psychology that get into scale development. It is worth getting a book like Aiken or another book to understand the issues with Likert scaling, Semantic Differential scales, odd versus even scales, whether to label each scale point or only the end points. Chauncey > No. I think the phrase 'force them to choose' shows exactly why this is a bad > idea. > > You ought to allow users to have the opinions that they have - even if those > opinions include 'don't know' or 'don't care' (or> both). > > The answer options you offer should depend solely on the answers that your > users want to give - not upon how many users there are. > > If you don't know what answers your users want to give, then interview them > to find out before running your survey. And by the way - > you should do that anyway (i.e., interview some users first) if you want > anything like good results from your survey. > > There's a longer version of my views at: > http://www.usabilitynews.com/news/article1269.asp > > Best > Caroline Jarrett > [EMAIL PROTECTED] > > > ________________________________________________________________ > Welcome to the Interaction Design Association (IxDA)! > To post to this list ....... [EMAIL PROTECTED] > Unsubscribe ................ http://www.ixda.org/unsubscribe > List Guidelines ............ http://www.ixda.org/guidelines > List Help .................. http://www.ixda.org/help > ________________________________________________________________ Welcome to the Interaction Design Association (IxDA)! To post to this list ....... [EMAIL PROTECTED] Unsubscribe ................ http://www.ixda.org/unsubscribe List Guidelines ............ http://www.ixda.org/guidelines List Help .................. http://www.ixda.org/help
