Hi, everyone.
I want some advice on using the Likert scale. I have some questions that need your help in answering.

Is neutral choice (middle point) necessary on the Likert scale? Why? Because I found that some researchers used odd points while the others used even points on the Likert scale.

I know that the Likert scale has variations in response categories from 2-point to 10-point scales. What is the optimal number of response categories that is preferable to use? Why?

From a general statistics standpoint, the more the better. I likek using slider buttons on web forms that provide a continuous output (actually internally coded as 0-100 but the users don’t see the numbers).

Came across this interesting paper on this very topic. I’m not so confident Rasch analysis can produce a metric scale from ordinal data, but it provides a decent introduction to the theory behind it.

I’m not sure that their Rasch analysis is the right basis for favoring simple scales with low resolution. I would base the decision on the ability of point-in-time scales to predict ultimate outcomes, and on statistical power.