What is the best place in a course to first take advantage of Courselets' ability to individualize where each student needs to focus?

• problem: one of the biggest root causes of disparities in STEM course outcomes is the simple fact that on any given prerequisite skill, up to 50% of students entering a course may have a significant misconception or blindspot, producing huge disparities before the class even begins.
• best practice: before the course starts, give your students a quick courselet that identifies their individual misconceptions immediately (within 60 seconds of their first attempt, for 90% of students), and then provides resolution lessons that fix those specific misconceptions. Such an online courselet of quick pre-requisite exercises will take little time for a student who has those skills. But any pre-requisite that a student lacks will redirect her to additional steps that help her with that specific skill, as much or as little as she needs.
• For students, such a prereq survey has immediate urgency ("what am I going to need to get a good grade in this class?") and immediate reward ("uh oh, looks like I have some worrying gaps... oh great, that really helped fix my understanding!").
• The Courselets data show that these blindspots are crucial "missing data" in STEM education: even very common blindspots (blocking up to 40% of students) are not addressed in the textbook. Hence in practice blocked students have nowhere to turn. So direct intervention via a platform designed to resolve blindspots is the clear way to solve this.
• This gap between what's uniform in a class (its assignments) vs. what's not (the student's differing backgrounds) is arguably the most valuable place for Courselets' automatically individualized exercise. Within the class the instructor provides a uniform experience, but everything that came before the class is both out of their control and actually not uniform across the students!
• Adding such a pre-requisites courselet as an online exercise has little effect on the class' existing assignments and syllabus. The instructor doesn't have to change anything in the class, to take full advantage of this individualized approach.