Activity 13.4:

Random Selection vs. Random Assignment

Described below are four examples of randomization. Write RS if random selection is involved; RA if random assignment is involved; B if both random selection and random assignment are involved; or O if no randomization is involved.

1.Using all fifth-grade classes in the campus demonstration school, a researcher divides the students in each class into two groups by drawing their names from a hat.

2.All students with learning handicaps in a school district are identified and the names of 50 are pulled from a hat. The first 25 are given an experimental treatment, and the remainder are taught as usual.

3.All third-grade students in an elementary school district who are being taught to read by the literature method are identified, as are all students who are being taught with basal readers. The names of all students in each group are placed in a hat and then 50 students from each group are selected.

4.Students in three classes with computer assistance are compared with three classes not using computers.