In her research for the second shift, arlie hochschild interviewed married couples to find out how they dealt with changing family roles as more women entered the workforce. what advantages came from her decision to use interviews as a research method

I believe the answer is: It allowed her to gather direct quotations and construct an intimate portrait of married couples.

Couples are much more likely to say positive things about their partner if they they are both communicating directly with a third party. This would increase the amount of direct quotations that is build on the foudation to praise each other and create an intimate portrait of those couples.