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Chapter 2: Problem 37

The Institute of Psychiatry at Kings College London found that dealing with "infomania" has a temporary, but significant derogatory effect on IQ (Discover, November 2005\()\). In this experiment, researchers divided volunteers into two groups. Each subject took an IQ test. One group had to check e-mail and respond to instant messages while taking the test, and the second group took the test without any distraction. The distracted group had an average score that was 10 points lower than the average for the control group. Explain why it is important that the researchers created the two experimental groups in this study by using random assignment.

Short Answer

Expert verified
Random assignment was crucial in this experiment because it ensured that all participants had an equal chance of being in either group, reducing potential bias. This brought an even distribution of any potential confounding variables across the two groups, thus, enhancing the validity of the study's outcomes: the differences in IQ scores can be attributed to the effects of distraction rather than other factors.

Step by step solution

01

Understand the experiment

Firstly, we need to comprehend the experiment. It's about comparing two groups of volunteers. The first group takes an IQ test while checking e-mail and responding to instant messages; this group is called the distracted group. The second group takes the IQ test without any distractions; this group is referred to as the control group. The results show that the distracted group scores 10 points lower on average than the control group.
02

Define random assignment

Random assignment is a fundamental aspect of experimental design. It is the process of assigning subjects randomly to the control or experimental group. This is done to ensure the research study's validity, as it can help counteract the confounding variables that may impact the study鈥檚 results. Confounding variables are factors besides the independent variable that may cause or contribute to the effect.
03

Apply the defined concept to the experiment

In the context of this study, random assignment was important to ensure that each participant had an equal chance of being in either group, eliminating bias. This helps divide any potential confounding variables evenly between the two groups, improving the reliability of the outcomes. By doing so, any difference in the IQ test scores can be confidently attributed to the impact of the experiment's conditions (i.e., distraction vs no distraction).

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Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Random Assignment
Random assignment plays a crucial role in ensuring the fairness and reliability of an experiment. It involves randomly distributing participants into different groups, such as the experimental and control groups. This randomness helps ensure each participant has an equal chance of being in any group, which eliminates bias and helps distribute characteristics evenly.

By doing so, researchers can confidently attribute any differences between groups to the experimental conditions rather than other factors. In the "infomania" study, random assignment ensured that both the distracted and control groups could be reliably compared without influences from hidden variables.
Control Group
A control group is essential in experimental research as it serves as a baseline or reference point. This group is kept under normal or unchanged conditions to compare with the experimental group, which receives some form of intervention or treatment.

In the "infomania" study, the control group took the IQ test without distractions. This allowed researchers to compare the results of the distracted group to a "standard" scenario. By having this baseline, the study could effectively measure the impact of infomania on IQ scores. Without a control group, it would be challenging to determine the actual effect of distractions.
Confounding Variables
Confounding variables are factors that can potentially interfere with the outcome of an experiment. They are not the variables being studied but can influence the results if not properly controlled. By introducing random assignment and a control group, researchers can minimize the impact of these confounders.

For the "infomania" study, confounding variables could include pre-existing differences in IQ, stress levels, or familiarity with the testing procedure. The random assignment reduces these issues, as participants' characteristics are expected to be evenly distributed across groups. This ensures any observed effect on IQ scores is likely due to the experiment's manipulation, such as being distracted or not.

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Most popular questions from this chapter

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