Hi Guswin,

I suggest you take a look at an article in The American Psychologist that compares the findings in a variety of psychosocial research to findings in what are often thought to be the "hard sciences" like biology and medicine. I think you might be surprised to find that there is little difference in power of the findings.

Meyers et al (2001). Psychological testing and psychological assessment. 56(2) 128-165.

 Thank you so much for the direction provided by both of you. Could be very helpful