Paired, discrete hypothesis testing I am facing the following situation. I asked my class of 19 students to rate their interest about a certain topic on a 1-5 (discrete) scale. I then spent some time teaching them about this topic for a few hours after which I asked them to answer the same question. I now have two sets of 19 values and also know the pairing between them.
What would be the proper way of testing whether or not my teaching sparked their interest?
I was gonna do a dependent t-test for paired samples, but I'm concerned that the data does not follow a normal distribution. First of all it is discrete, but I was told that it is not an issue as long as it passes the SPSS normality tests. Unfortunately my distributions don't pass those tests.
Can I still do the t-test? What would be the analogous test for discrete (but still ordered) data?

The sign test or the Wilcoxon sign-rank test present alternatives to a permutation test.
The former has really low power, but a reasonably comprehensible null and alternative hypothesis:
$\text{H}_{0}\text{: }P(X_{\text{before}} > X_{\text{after}}) = 0.5$ , with
$\text{H}_{\text{A}}\text{: }P(X_{\text{before}} > X_{\text{after}}) \ne 0.5$
In plain words, the null hypothesis of the sign test is that a randomly selected student is equally likely to have a before measurement that is larger than their after measurement.
The sign-rank test has much more power, but the null and alternate are less intuitive:
$\text{H}_{0}\text{: The distribution of } X \text{ is symmetrical and centered on 0,}$ with
$\text{H}_{\text{A}}\text{: The distribution of } X \text{ is either asymmetrical, or not centered on 0, or both.}$
