In trying to determine how to adapt a Likert-style survey for quantitative data analysis, I found a research study from 1971 that stated it was the first of its kind to measure how many response options impact validity and reliability. The article is in the Journal of Marketing Research and written by Jacob Jacoby and Michael S. Matell. The title? “Three-Point Likert Scales Are Good Enough.” So great, there is my answer! I referenced this article, as have 167 others, and kept on going. To be sure, I double-checked on the authors. Jacob Jacoby has a Ph.D. in Social Psychology and teaches Research Methods at NYU. He wrote many books, articles, chapters, and appears to be a subject matter expert. I didn’t check on Michael S. Matell at that time, but since then have not found the same level of output. This study showed that the relationships of validity and reliability to number of alternatives in a survey, display a lack of significant difference between a multi-stepped, dichotomous, or trichotomous questionnaire format.
The following year (1972), the same journal asks “Are Three Point Likert Scales Always Good Enough?” This title is suggesting to me, “No.” The author, Donald Lehmann, a professor at Columbia University, is just as distinguished and impressive as three point Jacob Jacoby. You may agree, have no opinion, or disagree.
In Google Scholar alone, there are 234, 000 hits on “how many points on a Likert scale.” Consider culture, even vs. odd, the midpoint, and a Monte Carlo Approach. The Monte Carlo approach is a mathematical model that determines a way around the acknowledged (thank you!) contradictions and confusion about the optimal number of points for reliability. I did not read this article, but the title is encouraging.
One of the best things I can do here for now is to get out of the 1970s and adjust my research options to at least the past four or five years. It brings me down to only 15,430 hits. It should keep me busy, and I will let you know what I end up with.
Even better, would anyone mind letting me know? How many points do you strongly agree should be on the Likert scale? Also, could you include a reference?