Implementation Measures
We tested whether calls from research assistants were successful in prompting parents to engage with the handbook. This dichotomous measure was coded as 0 for no contact and 1 for contact with parents. In the fall data collection, we assessed parent engagement by asking how many hours they spent reading the handbook and how many hours they spent actually doing handbook activities with their student (both items rated on a 9-point ordinal scale ranging from “none, I did not read any of the handbook/do any of the activities” to “more than 10 h”). We also asked parents how useful and how engaged they thought their student was with the activities (both items rated on a 4-point response scale ranging from “not at all” to “extremely”). Students reported whether they remembered their parents reading the handbook and whether they did any of the activities together (responses of “yes” and “no”).