hello! I have a problem. Im a soil scientist. Im trying to make an optimization about my thesis results. My PhD thesis was " Effects of some soil conditioners on soil physical properties" Its a field experiment. I applied 7 different materials to soil during 3 years. Also, I collected 2 soil samples for each year. I investigated 7 soil physical properties (Bulk density, SSI, field capacity, etc...) How could I desing it for optimization? How many factors and levels I have? How could I make it by Minitab? Thanks for helping advance.