Limitations: Discuss factors that affect the results. Hillock conducted a study using three treatments: observational or data collecting activities prior to writing, use of revisions or absence of same, and either brief or lengthy teacher comments to identify effective methods of teaching composition to seventh and eighth graders.
Members of the evaluation section of Harvard project physics describe what is said to be the first attempt to select a national random sample of teachers, and list 6 steps to do so. Participants might have changed between the pretest and the posttest in ways that they were going to anyway because they are growing and learning.
Curriculum Inquiry, 26, The study was not a case study, but it provided insights into the attitudes and feelings of small clusters of student writers.
Types of Experimental Design There are two basic types of research design: True experiments Quasi-experiments The purpose of both is to examine the cause of certain phenomena.
Journal of Reading, 27, If there had been only one measurement of absences before the treatment at Week 7 and one afterward at Week 8, then it would have looked as though the treatment were responsible for the reduction.
Imagine, for example, that students in one school are given a pretest on their attitudes toward drugs, then are exposed to an antidrug program, and finally are given a posttest.
The author discusses both non-experimental and experimental research and the need for using random assignment. You must ensure that you use the same plant; that both groups are put in the same kind of soil; that they receive equal amounts of water and sun; that they receive the same amount of exposure to carbon-dioxide-exhaling researchers, and so on.
Research regarding research: an investigation of the effects on the outcome of an experiment in which information about the experiment had been leaked to subjects. Reading and skimming from computer screens and books: The paperless office revisited?