When the conditions of a study resemble or approximate only the conditions of interest, questions may be raised about the ''blank'' of the study.

Question

A external validity
B internal validity
C standardization
D randomization

This question is very difficult for me. I can't find exactly the right answer in my text book. I believe is A but I'm not at all sure.

Answer 1

I think you're right.

http://www.gifted.uconn.edu/siegle/research/Samples/externalvalidity.html