I am running a quasi-experiment with English proficiency as a factor (native speakers=9, ESL speakers=10)
I just completed a pilot and fully plan to conduct the intervention as closely to the pilot's procedures as possible--I am measuring the same DVs. I was hoping I could use the pilot as a "control group" of sorts to talk about the characteristics of the groups before intervention.
However, I have to change a few things in the procedure. For example, a lot of the ESL students did not understand my instructions, so I plan to display the instructions using graphics instead.
So my question is: can I still use the pilot results to compare with post-intervention results, even if the procedures are not identical?