If you are using normalized gains, be sure to cite Hake in the methods chapter when describing normalized gains. 

Like this in methodology:

The normalized gain was calculated to determine differences in student knowledge. Normalized gains of

less than 0.3 percent were considered low, gains 0.3 to 0.7 were considered a medium gain and normalized 

gains greater than 0.7 were considered high (Hake, 1998).


In the analysis chapter, refer to the low, medium, high gains Hake has identified.

The normalized analysis of the Jones Pre/Post-inquiry Test showed a gain of .45, considered a medium gain (Hake, 1998).  

Use this in the reference section:

Hake, R. R. (1998). Interactive-engagement versus traditional methods: A six-thousand-
student survey of mechanics test data for introductory physics courses. American Journal of Physics, 66(1), 64-74.