Besides the mention of the original Ruby project you might want to put a link somewhere to the project (maybe in the README.md).

I think I have written something like scientist4j accidentally several times but just using JUnit + Guava Stopwatch + logger + java random. If its critical cpu path I use JMH. I never thought to package it up as a library. scientist4j is basically a benchmarking tool + unit test right? I think though I might be missing something?

How can I provide parameters to the experiment function?

Pass it a lambda.

Very cool, thanks for porting this.