The problem of summer reading loss among low-income children has been amply documented by researchers. Over time, income-based disparities in reading achievement appear to grow more rapidly during the summer months than the academic school year. This paper describes two experiments in which teachers scaffold summer book reading with two different approaches to improving comprehension through end of school year lessons. Because teachers implemented different comprehension lessons in the two studies, the instructional activities varied across the two studies. Both studies used the same norm-referenced reading comprehension test (Iowa Test of Basic Skills), enabling a comparison of impacts on a similar measure across two studies. The purpose of this study is to capitalize on the lessons from the two experiments. Results from the 2006 experiment, which focused on comprehension strategy instruction, improved children's performance on comprehension tasks that required inference and interpretation (d = 0.15). Results from the 2011 experiment suggest that content-oriented comprehension instruction improved children's performance on tasks that required analysis and generalization (d = 0.11) compared to strategy-oriented instruction. In study 1, strategy lessons appeared to benefit Grade 4 children's ability to make inferences and interpretation. In study 2, content lessons appeared to benefit Grade 3 children's ability to make analyses and generalizations. Tables are appended.