I am working on a student's dissertation and have come across a use of Likert survey questions to establish groups to analyze for differences. What the student has done is use a series of questions to break the respondents into groups....those with higher than average responses on a series of questions and those with lower than average responses. He has used the middle of the likert survey scale (in this case 1,2,3,4,5) with 3 being the average or middle. If a respondent has answered 1 or 2 he is segregated into a "lower" category. If a respondent has answered 3, 4 or 5 he is segregated into a higher category. By this means the researcher has built two groups (lets call them lower and higher) and then looked for differences in other question groups on the survey. I have never seen this done in social research before and wondered if this was an acceptable means to build groups other than using demographic data? Any and all feedback would be appreciated.

ballengerb1

So the pretest was like establishing a baseline of existing knowledge, then knowledge gained from seminar and finally long term retention of that knowledge, along those lines?? I can picture how this could be valueable to a presenter to determine his effectiveness but I need to stop here, Elvis's brain has left the store.

kingkarl

Exactly, this is classic pretest/post test and uses the paired t-Test to analyze for difference between the pretest knowledge and the posttest knowledge. This experimental design is classically used to evaluate a new teaching method, but is also used to evaluate diet programs (weigh, diet, weigh), blood pressure medicine effectiveness (blood pressure test, medicine for 6 months, then blood pressure testing again). A most effective, but slightly different way to analyze for difference in a common variable before and after a treatment.