A cognitive psychologist wants to determine if a new mnemonic training program improves memory recall. A sample of 25 participants is tested on a recall task before training, and then tested on an equivalent task after completing the training. The recall scores (number of items correctly recalled) represent interval-level data, and the distribution of the difference scores is found to be normally distributed with homogeneous variance.

Which inferential statistical test is the most appropriate to analyze whether there is a significant difference between the pre-training and post-training scores?