Effectiveness of teaching software. The U.S. Department of Education (DOE) conducted a national study of the effectiveness of educational software. In one phase of the study, a sample of 1,516 first-grade students in classrooms that used educational software was compared with a sample of 1,103 first-grade students in classrooms that did not use the technology. In its Report to Congress, the DOE concluded that “(mean) test scores (of students on the SAT reading test) were not significantly higher in classrooms using reading … software products” than in classrooms that did not use educational software.

a. Identify the parameter of interest to the DOE.

The sample size of first-grade students in classrooms that used education software is 1516.

The sample size of first-grade students in classrooms that didn’t use education software is 1103.

If \({\mu _1}\) and \({\mu _2}\) are the two means of a population, and the type of the data is quantitative, then the target parameters of the mean difference can be represented\({\mu _1} - {\mu _2}\).

Let \({\mu _1}\) be the mean test score of the first-grade students on the SAT reading test in classrooms that used educational software and \({\mu _2}\) be the mean test score of the first grade students on the SAT reading test in class rooms that didn’t use the educational software.

Therefore,

The parameter of interest is\({\mu _1} - {\mu _2}\).

i.e., The \({\mu _1} - {\mu _2}\) is the difference between the mean test score of the first grade students on the SAT reading test in classrooms that used educational software and didn’t use the educational software.

Hence, the parameter of interest is\({\mu _1} - {\mu _2}\).