To compare the results of your pages with and without Personal Merchandising, you can set up an A/B test.
The A/B Testing module in Tweakwise allows you to compare the performance of two different configurations (for example, two different sorting orders, builder templates, or filter templates). You use A/B tests to determine in a data-driven way which adjustments in your Tweakwise setup yield the best results, such as a higher conversion rate or more revenue. You test a control version (A) against a variant (B) to see which performs better.
Here you can read how to set up an A/B test!