Hypothesis

Independent Variable

Dependent Variable

Basic Two-Group Experimental Design

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A researcher wants to test if a new public speaking workshop reduces anxiety. They measure the anxiety levels of 50 volunteers before they participate in the workshop. A week after the workshop is completed, the researcher measures their anxiety levels again and finds that the average anxiety level has decreased. The researcher concludes the workshop is effective. What is the most significant flaw in this study's design?

Operational Definition

Simple Random Sampling

Confederate

Confederate in Research

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Advantages of Between-Subjects Experiments

Independent-Samples t-Test

One-Way ANOVA

Within-Subjects Experiment

Matched-Groups Design

Examples of Between-Subjects Experiments

Example of Lack of Context in Between-Subjects Designs

Combining Between-Subjects and Within-Subjects Designs

Equivalent Groups

Nonequivalent Groups

Which of the following best describes a between-subjects experiment?

In a between-subjects experiment, researchers test each participant across every level of the independent variable to directly compare their individual responses.

A researcher is conducting a between-subjects experiment to test if '8 hours of sleep' versus '4 hours of sleep' affects cognitive performance on a memory task. Arrange the steps of this specific study in the correct chronological order.

A researcher investigates whether a new font improves reading speed. They assign 50 participants to read a text in 'Times New Roman' and another 50 participants to read the same text in 'OpenDyslexic'. Match each aspect of this study to the structural logic of a between-subjects experiment.

You are tasked with creating a research protocol to investigate whether a 'Gamified' exercise app increases user motivation more than a 'Standard' exercise app. To avoid 'carryover effects'—where the experience with one version of the app might influence the user's perception or performance with the other—you decide to implement a between-subjects experiment. Which of the following plans should you develop to successfully fulfill this design requirement?

A researcher is evaluating whether to use a within-subjects or a between-subjects design for a study on a permanent educational intervention. They determine that a(n) _____ design is the only valid choice because the intervention results in an irreversible change, making it impossible for the same participants to serve in both the experimental and control conditions.

An experimental design in which each participant is exposed to only a single level of the independent variable is called a(n) _____ experiment.

A clinical researcher measures each participant's stress level at three time points: before a mindfulness program begins (Week 0), after four weeks of training (Week 4), and after eight weeks of training (Week 8). Every participant completes the same single program. The researcher argues that this is a between-subjects design because each participant is assigned to only one program. This argument is correct.

A researcher studies whether type of reward (monetary payment, verbal praise, or no reward) affects how long elementary school children persist on a difficult puzzle. One group receives money after each puzzle attempt, a second group receives verbal praise, and a third receives nothing. No child participates in more than one condition. Match each term to the description that correctly identifies its role in this study.

A research team wants to test whether a new anti-anxiety drug (Drug A), an established drug (Drug B), or a placebo reduces self-reported anxiety in adults with generalized anxiety disorder. They must design the study and analyze the data responsibly. Arrange the following decisions and actions in the order that best reflects sound research practice for a between-subjects experiment.

Placebo

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What is the primary purpose of experimental control in a research study?

Match each component of experimental control with its specific role in a psychological experiment to demonstrate how researchers isolate causal effects.

A cognitive psychologist is studying the effect of word length on memory. To maintain experimental control, the psychologist ensures that all participants see the words on the same computer screen, at the same distance, and for the same duration of time.

A researcher is studying the effect of a new 'Focus App' on student productivity. To ensure that the app is the actual cause of any improvement, the researcher must apply experimental control. Arrange the steps of this process in the correct logical order to demonstrate how control isolates the independent variable.

The primary purpose of experimental control is to prevent extraneous variables from fluctuating across the different conditions of a study.

A researcher investigating a new study technique ensures that all participants take their practice tests in the same quiet room at the same time of day. Which statement best interprets the scientific rationale for this application of experimental control?

A researcher claims that a specific exercise program increases mental clarity, but they fail to hold the participants' daily caffeine intake constant across the different groups. Because the researcher did not maintain experimental control over this outside factor, a scientific evaluator would conclude that the researcher cannot make a valid causal _____ regarding the program's actual effect.

A cognitive psychologist is investigating how different lighting levels affect reading comprehension. Match each element of this study to the correct variable type or control function to show how the researcher isolates the causal effect.

In a study testing a new memory drug, the researcher tests the drug group in the morning and the placebo group in the afternoon. Because time of day was allowed to fluctuate across conditions, the researcher failed to maintain experimental control over this _____, making it difficult to isolate the true effect of the drug.

Arrange the steps in the logical order a researcher must follow to evaluate and establish experimental control in a study testing a new reading application.