Likert-scale questionnaires/tests tend to include the following options:
- Strongly agree
- Neither agree nor disagree (sometimes included)
- Strongly disagree
I have been looking for a rigorous definition of what it means to "strongly" agree or disagree with a statement as opposed to simply agreeing or disagreeing with it. What is "strongly" intended to mean in theory when it comes to Likert questions? Clearly, some type of qualitative judgment is countenanced, but what is the actual construct that is theoretically supposed to be measured?
- Does it represent the intensity of emotion felt by the test-taker when considering the truth or falsity of the statement?
- Does it represent the test-taker's intellectual confidence level in the truth or falsity of the statement (e.g. someone who believes that there is a 55% likelihood that the statement is true should respond agree while someone who is 95% confident should respond strongly agree)?
- Does it represent whether the test-taker accepts the truth or falsity of the statement based on evidence or whether they take it on faith (e.g. "I strongly agree with the proposition P because I have done research in that area and have found extensive evidence of its truth. I only agree with proposition Q. I have not done research in the area or even read much of the research, but my cultural group accepts Q on faith and that's good enough for me.")?
- Does it represent the importance of the truth or falsity of the statement to the test-taker's identity, world view, or goals?