Help me decide which statistical analysis to run for my study, small sample statistics.

Question

For my study, I have a group of 13 participants. Each participant was administered a pre-intervention battery of four psychological measures. The first two measures produce one total score (continuous) each. The last two measures both have a total of 5 scores (also continuous). So these last two measures have five dimensions each.

1. Measure 1 produces one continuous score.

2. Measure 2 produces one continuous score.

3. Measure 3 produces 5 different scores (as the measure is looking at 5 different factors).

4.Measure 4 produces 5 different scores (as the measure is looking at 5 different factors).

Each participant then receives a psychological intervention. A week after they finish the intervention, they take the same battery of measures again.

I know this is a small sample, but I want to analyze the data to see if there are any significant differences between the groups overall in each of the measures, and also, to see whether the participant's showed any differences on an individual level on their pre- and post-intervention measures.

Which statistical analysis would I use if the data met all assumptions?

Which small sample statistic could I use, or non-parametric statistic could I use if the data does not meet assumptions?

Thank you!

Answer 1

You can use regression. You need to make dummy variables properly for the categorical factors. Say, one factor has k categories, you need to make k-1 dummy variables for the k-1 category and one will be referent category and you include the k-1 dummy variables in your regression.