We know that most of what we learn we forget. This is especially true if we do not retrieve newly learned information shortly after learning it. However, it is common for teachers to move to the next unit after a test and shelve the knowledge on which students were just tested.
Proponents of final exams sometimes point to this reality as a reason to give finals. Finals force students to look back at what they were taught and remember or relearn it. But isn't this just "wash, rinse and repeat"? Isn't the knowledge going to be forgotten yet again within short order?
A useful shift for all of us in the teaching business is to ask students to know how insteading of asking them to know what. I'll be the first to admit that this dichotomy I pose is in some ways false. I had supervisor I respected who argued the what didn't really matter. I disagreed. Knowing how sometimes requires knowing what. In teaching students to write a proper paragraph, we have to to teach them what to do. This supervisor would have said, "Of course, that is a skill." In the humanities, however, there are ways of knowing where the what must come first. Before my students can analyze international events from the competing international relations' theories of realism, liberalism, constructivism, and neo-conservatism, they need to know these paradigms.
This caveat aside, there still is an important distinction to make. Consider, what do your tests look like? Do they ask students what questions or how questions? Do your tests ask for recall or comprehension, Or better yet, do your questions promote the higher order thinking skills application, evaluation and analysis?
Consider these two questions from +Michael Gorman