tests in their summary, out of 54 studies he identified that might have been used. In 10 of the studies used by NRP, SSR students performed the same as other students, and in 4 studies, SSR students did better. However, some argue the NRP is not impartial at all. The NRP only included studies that were verifiable and with scientifically credible designs. The NRP had rigorous guidelines for the studies it would include. For example, the NRP did not include studies without control groups. The fact that the NRP only analyzed 14 SSR studies, shows that the other studies were not scientifically credible. In the full group of 54 studies, SSR students performed better in 25, worse in 3, and the same in 24. SSR students scored worse only in short-term studies of less than seven months. In studies that lasted one year or longer, SSR students did better in 8 of 10, and there was no difference in the other two. The NRP found that most of the SSR studies were not valid or verifiable. Many studies were simply correlational. Thus, only 14 studies followed guidelines that could make them statistically significant. Of these studies, SSR was found ineffective. "Where do these negative SSR feelings come from?" Trelease asks. "Perhaps from the wonderful folks who make all those workbooks, textbooks, and score sheets that wouldn't be bought and used in class during the time students were lounging around reading books, magazines, and newspapers and getting so good at reading they might need even fewer of those sheets next year." There is some support for this charge: A blog titled "Why Sustained Silent Reading (SSR) Doesn't Work" is posted by the publisher of four workbooks that sell for $89.99 each. Sustained silent reading practices A range of practices have been associated with SSR, and some advocates suggest that teacher models of reading behavior (i.e., teachers read while the students read), a long-term commitment to SSR, availability of multiple level, high-interest texts, and a sense of reading community are particularly relevant. Free voluntary reading Free voluntary reading (FVR) or recreation reading, related to the comprehension hypothesis, is an educational theory that says many student gains in reading can be encouraged by giving them time to read what they want without too many evaluative measures. Sustained silent reading is a method of implementing recreational and FVR theory. Other names for SSR Uninterrupted