I found some MS-DOS TSR program that would flash messages on the screen at specified duration or frequency.

I told my test subjects (other students) I was testing if typing in vocabulary words helps learn them more efficiently.

I made up a set of 50 words and definitions. Each student got a random mix of words and definitions to type in, while other words were flashed on the screen subliminally.

I then gave a test which covered both sets of words.

I think I originally tested three different subliminal message durations, and one of them was showing a slightly-higher average test score.

I then realized I needed a control group, so I tested another batch of students without any subliminal messages at all. The control batch got the highest scores of all.

Don't remember details, but I did actual statistics on the data and failed to reject the Null hypothesis.

Ie - my conclusion was that flashing word/meaning subliminal messages didn't make any difference to testing those same words in a quiz.

It was a fun project, but I realized later it wasn't very scientific. The message duration would actually vary greatly depending on the model of monitor (the old CRT days). And I didn't really have control on how much time the person looked at the screen vs the keyboard.

But it was fun anyway. I was also chosen as one of eight high school kids to present at the local county science symposium too.