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Many universities and colleges have instituted supplemental

instruction (SI) programs, in which a student facilitator meets regularly with a small group of students enrolled in the course to promote discussion of course material and enhance subject mastery. Suppose that students in a large statistics course (what else?) are randomly divided into a control group that will not participate in SI and a treatment group that will participate. At the end of the term, each student鈥檚 total score in the course is determined.

a. Are the scores from the SI group a sample from an existing population? If so, what is it? If not, what is the relevant conceptual population?

b. What do you think is the advantage of randomly dividing the students into the two groups rather than letting each student choose which group to join?

c. Why didn鈥檛 the investigators put all students in the treatment group? [Note:The article 鈥淪upplemental Instruction: An Effective Component of Student Affairs Programming鈥 (J. of College Student Devel., 1997: 577鈥586) discusses the analysis of data from several SI programs.]

Short Answer

Expert verified

a. No, All the students taking a large statistics course who participate in an SI program.

b. The randomization eliminates any biases and ensures that the students in the SI group are as similar as possible to the students in the control group.

c. The comparison of the SI scores cannot be done if all the students are put in the treatment group.

Step by step solution

01

Given information

It is given that the students in a large statistics course are divided into the control group that will not participate in the supplemental instruction (SI)program and a treatment group that will participate in SI.

02

Check whether the scores from the SI group a sample from an existing population

a.

The scores from the SI group are not a sample from an existing population because the population is divided into control and treatment group.

The relevant conceptual population is,

All the students taking a large statistics course who participate in an SI program.

03

State the advantage of dividing the students into two groups.

b.

The advantage of randomly dividing the students into two groups rather than letting each student choose which group to join is that the randomization eliminates any biases and ensures that the students in the SI group are as similar as possible to the students in the control group.

04

Explain why all the students cannot be in the treatment group.

c.

All students cannot be put in the treatment group because there will be no criteria for assessing the effectiveness of the SI.

Therefore, the comparison of the SI scores can not be done if all the students are put in the treatment group.

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Most popular questions from this chapter

a. If a constant cis added to each \({x_i}\)in a sample, yielding \({y_i} = {x_i} + c\), how do the sample mean and median of the \({y_i}'s\)relate to the mean and median of the\({x_i}'s\)? Verify your conjectures.

b. If each \({x_i}\)is multiplied by a constant c,yielding \({y_i} = c{x_i}\), answer the question of part (a). Again, verify your conjectures.

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