An employment test for men is used by a police department to find successful candidates. A woman who was denied employment with the police department based on her test scores sues the police chief. She claims in her suit that the test cannot be used to predict her job performance since it has been used only with men. This claim raises a question of:

Cross-population generalization                

Explanation:

In simple terms, the generalizability of cross population means the ability to generalise through one category, community to other communities or groups.  Such method is used to define a process that if ti fits properly to all the inputs so that measurement of output can be done without any bias.

This method is commonly used in the field of farming biology where different seeds are studies cross sectional to study the implications of resulting output.