From the given description, Chip is using an experimental design called (A) matching.
Matching <u>is a type of experimental design where the researcher divide his or her samples into two groups of treatment conditions, which serves to ensure that before the treatment, both groups have the samples with the same characteristics, thus ensuring that the results of the experiment would not be influenced by any confounding variables that the samples have.</u>
Chip is doing this to ensure that samples that have been influenced by other variables which determine their decision to hire are distributed evenly in both the experimental and control group.
