In Exercises 9 and 10, determine whether the study is an observational study or an experiment. Explain.


To study the effect of using digital devices in the classroom on exam performance, researchers divided 726 undergraduate students into three groups, including a group that was allowed to use digital devices, a group that had restricted access to tablets, and a control group that was “technologyfree.” (Source: Massachusetts Institute of Technology)

Verified step by step guidance

1. Step 1: Understand the difference between an observational study and an experiment. An observational study involves observing subjects without manipulating variables, while an experiment involves actively manipulating one or more variables to observe their effects on outcomes.
2. Step 2: Identify the key elements of the study described in the problem. Researchers divided 726 undergraduate students into three groups: one group allowed to use digital devices, one group with restricted access to tablets, and a control group that was technology-free.
3. Step 3: Determine whether the researchers manipulated variables. In this case, the researchers actively assigned students to specific groups with varying levels of access to digital devices, which indicates manipulation of the independent variable (use of digital devices).
4. Step 4: Recognize that the manipulation of variables and the division of participants into groups are hallmarks of an experimental study. This setup allows researchers to observe the effect of digital device usage on exam performance.
5. Step 5: Conclude that this study is an experiment because the researchers controlled and manipulated the conditions under which the participants operated, rather than simply observing them in their natural settings.

Key Concepts

Observational Study

An observational study is a research method where the researcher observes and records behavior or outcomes without manipulating any variables. In this type of study, the researcher does not intervene or assign treatments; instead, they simply collect data on subjects in their natural settings. This approach is useful for identifying correlations but cannot establish causation.

Experiment

An experiment is a research design in which the researcher actively manipulates one or more independent variables to observe the effect on a dependent variable. This method typically involves random assignment of participants to different treatment groups, allowing for control over confounding variables. Experiments are essential for establishing causal relationships between variables.

Control Group

A control group is a baseline group in an experiment that does not receive the treatment or intervention being tested. This group is essential for comparison, as it helps researchers determine the effect of the treatment by providing a standard against which the experimental groups can be measured. The presence of a control group enhances the validity of the study's findings.