The Advanced Level Certification for Usability Testing (CPUX-UT) has now been in existence for over eight years. The curriculum has been refined over the years. Based on more than 100 usability tests conducted during the practical examination, Rolf Molich, Bernard Rummel and Susanne Waßerroth have now summarized their findings as examiners and published them in an article in UXPA Magazine.
You can read all the results at:
https://uxpamagazine.org/improve-your-usability-tests-learnings-from-evaluating-100-plus-usability-tests/