I think I did something really simple concerning water preservation of apple slices and then testing it with different amounts of salt. It sounds really stupid, the experiment was easy (and took a lot of time actually) but I put a lot of scientific research into my discussion and explanations. Plus my experiment was unique, no one did it in the grade, so it wasn't seen as simple, I guess.
I don't even know, I got full marks for the SRP, if I find it, I can attach it or something.
alright alright ~90% darkness? maybe. But do keep in mind that different colours have different luminosity levels and the type of ink affected it too. i.e. laser printer vs inkjet, laser wins! (due to higher luminosity - hard to explain and I'm not going into IST terms like my teacher did..)
The teacher isn't marking the difficulty of the experiment or how "hard" or "easy" it is. She's marking the way you write up your report. Choose something easy and write up an extremely detailed report. You'll ace it!