Our target article (Robinson-Cimpian, Lubienski, Ganley, & Copur-Gencturk, 2014) used nationally representative data to examine the development of gender gaps in math achievement. We found that when boys and girls demonstrate equivalent math test performance and are perceived by their teachers to be equally well behaved and engaged with the material, teachers tend to rate girls as less proficient in math than boys (Study 1). Moreover, this underrating of girls’ proficiency appeared to contribute substantially to a widening gender gap in early elementary school (Study 2). In this response, we use the thoughtful comments of Card (2014) and Penner (2014) as a springboard for discussing the methodologies and assumptions of some of the most recent research using nationally representative data to explore gender inequities. In the process, we shed light on how recent works using the same data reach different conclusions. We also make recommendations regarding the use of such data for understanding the development of the gender gap and for designing effective interventions.