Workers who survive a layoff of other employees at their...

Workers who survive a layoff of other employees at their location may suffer from “survivor guilt.” A study of survivor guilt and its effects used as subjects 120 students who were offered an opportunity to earn extra course credit by doing proofreading. Each subject worked in the same cubicle as another student, who was an accomplice of the experimenters. At a break midway through the work, one of three things happened: Treatment 1: The accomplice was told to leave; it was explained that this was because she performed poorly. Treatment 2: It was explained that unforeseen circumstances meant there was only enough work for one person. By “chance,” the accomplice was chosen to be laid off. Treatment 3: Both students continued to work after the break. The subjects’ work performance after the break was compared with performance before the break.$^{34}$ Describe how you would randomly assign the subjects to the treatments (a) using slips of paper. (b) using Table D. (c) using technology.

Workers who survive a layoff of other employees at their location may suffer from “survivor guilt.” A study of survivor guilt and its effects used as subjects 120 students who were offered an opportunity to earn extra course credit by doing proofreading. Each subject worked in the same cubicle as another student, who was an accomplice of the experimenters. At a break midway through the work, one of three things happened:

Treatment 1: The accomplice was told to leave; it was explained that this was because she performed poorly.
Treatment 2: It was explained that unforeseen circumstances meant there was only enough work for one person. By “chance,” the accomplice was chosen to be laid off.
Treatment 3: Both students continued to work after the break.

The subjects’ work performance after the break was compared with performance before the break.$^{34}$ Describe how you would randomly assign the subjects to the treatments

(a) using slips of paper.
(b) using Table D.
(c) using technology.

Key Concepts

Experimental Design

Experimental design is an overall framework that outlines how experiments are conducted, particularly how treatments are administered and how subjects are allocated into groups. A good experimental design incorporates proper random assignment procedures to ensure that differences in outcomes can be attributed to the manipulation of the independent variable rather than to other confounding factors.

Randomization Methods

Randomization methods are the various procedures and tools used to implement random assignment. These include manual methods like drawing slips of paper, utilizing random number tables, and employing computer-generated random sequences. Each method serves the same purpose—to eliminate systematic biases in the allocation of participants across experimental conditions.

Random Assignment

Random assignment is the process by which participants are placed into different groups using chance procedures, ensuring that each participant has an equal likelihood of being assigned to any group. This helps strengthen causal inferences by minimizing potential preexisting differences among groups and reducing selection bias.