Lauer Chapter 8

I'll focus on O'Hare's 1973 experiment on grammar instruction in Urbana, IL. The participants in this study were 83 seventh-graders, randomly assigned. There were two treatment and two control groups. A shortened version of the English curriculum was presented to the treatment groups, and the other group had sentence-combining exercises, though without formal grammar instruction. The research questions centered around the different sentences (syntactically) that students might write, based on the two groups. Also, he wanted to know if the treatment group would write better compositions. He hypothesized that the experimental group would write much better compositions than the control group. These differences would be significantly superior, according to O'Hare. The context of the study seems to be the typical role of researcher studying writing ability, in this case with a randomized experiment. O'Hare's results included post-test means and the standard deviation (p. 163 has the full list) for six criterion variables. The conclusion is that sentence combining did produce major effect sizes.
O'Hare was intelligent enough to include a composition pretest. Since some students dropped out, this allowed him to determine how these dropouts influenced the data.
After analysis, O'Hare concluded that sentence-combining was the cause of the changes he noted, based on the hypothesis questions.
I would have expected more students to drop out from the study, given that 83 participated. If that happened, the results would perhaps be more difficult to determine, even with the pretest. Keeping participants in a study that they have signed up for is difficult, as I know from having been a participant in various studies. I would also expect that external variables would affect the study, though in this case it's difficult to say just how much they would do so. It wasn't clear how these 7th graders differed. Sentence-combing seems dated today, at least to the extent that I do not often hear of it being taught.