If you are in class and the teacher says that you have a test the next day, what are you going to do? The most common thing to do is study for the test. But why? Isn't a test supposed to measure what we have learned so far? If we encouraged students to study right before the test, we are measuring their ability to study.
When I took an astronomy class in college, there was no need to study. The class was held in a planetarium where we gazed upon the stars in pitch darkness. The professor had a laser pointer and pointed at different parts of the sky while he told stories. He told the story of Orion and Taurus with the Pleiades. Spoke about the illusory distance between the stars on Orion belt. Introduced us to parsecs as unit of measurements.
On clear nights, we would go out and look at the sky through telescopes made by students in a different class.
When it was time to take a test, we already knew everything. When you have looked through the lens with your own eyes, it's easy to differentiate a reflective telescope vs a refractive one. When the story is interesting, you remember the names. When the dates are major events you can relate to, you memorize them effortlessly. The test only reveals what you understood and what you didn't.
Even a Math class can be taught in an interesting way. Very few students can thrive when the professor regurgitate dry, yeastless factuality. The Pythagorean theorem stuck in my head because we used it to measure earth's radius. And with that information, I was able to measure its circumference. I knew how long I would have to drive non-stop to go around the world. How cool is that for a kid? You'd never have to study for it before the test.
Tell stories students can relate to and your tests will be a more accurate measure of knowledge.