Key Concepts in Experimental Design and Ethics

Flashcards covering key concepts in experimental design, ethics, validity, and internal validity.

Experiment

A study conducted to answer a question about the causal relationship between two variables.

Control Variable

A variable that is kept constant between groups in an experiment.

Control Group

The group that does not receive the independent variable, used for comparison.

Random Assignment

A method of assigning participants that increases the chance the groups are equal and eliminates systematic differences.

One Way Design

An experimental design where only one independent variable (IV) is manipulated.

Between Subjects Design

An experimental design that compares different people against each other.

Posttest Only Design

A design where participants undergo manipulation and then complete the measures once.

Pretest-Posttest Design

A design where participants complete measures before and after manipulation.

Within Subject Design

An experimental design that compares the same participants against themselves.

Order Effects

Effects that occur when the sequence of conditions affects participant responses.

Counter Balance

A technique used to mitigate the effects of order by varying the order of conditions.

Pseudoscience

Ineffective or harmful treatments that have been disproven by science but are still used.

Manipulation Check

A check to determine the effectiveness of a manipulation in an experiment.

Floor Effect

A situation where all scores cluster at the low end of a measure.

Ceiling Effect

A situation where all scores cluster at the high end of a measure.

Debriefing Participants

The process of explaining the true purpose of the study to participants after its conclusion.

Ethics

Moral principles that govern a person's behavior or conduct of an activity.

Informed Consent

The process of ensuring that participants are fully aware of the nature of the study and its potential risks.

Nuremberg Code

A set of ethical principles for human experimentation developed after World War II.

IRBs (Institutional Review Boards)

Committees that review research proposals to ensure ethical research standards are met.

Face Validity

The degree to which a measure appears to assess what it is supposed to measure.

Content Validity

The extent to which a measure includes all relevant components of the construct being measured.

Concurrent Validity

The degree to which a measure correlates with a well-established standard measure.

Predictive Validity

The extent to which a measure can predict future behavior or outcomes.

Convergent Validity

The degree to which a measure correlates with other measures of the same or similar constructs.

Discriminant Validity

The extent to which a measure does not correlate with measures it should not relate to.

Internal Validity

The ability to rule out alternative explanations for a causal relationship in a study.

Single Blinded Experiment

An experiment where participants do not know which condition they are in.

Double Blind Experiment

An experiment where both the observer and the participant do not know which condition participants are in.

Placebo Effect

A phenomenon where participants experience effects from a treatment they believe to be effective, despite it having no actual therapeutic value.

Attrition

The loss of participants from a study, which can affect the study's results.

Regression to the Mean

The phenomenon where extreme scores tend to move closer to the average on subsequent measurements.

IV + DV quantitative

correlation test

IV categorical (2 groups) + DV quantitative

independent samples t-test

IV categorical (2+ groups) + DV quantitative

ANOVA

IV + DV categorical

chi-squared test

type 1 error

false positive - study says it works, doesnt actually work

type 2 error

false negative - study shows it doesnt work when it actually does

Fatigue Effects

A type of order effect in which performance declines over time due to participants becoming tired or bored from repeated tasks.

Practice Effects

A type of order effect in which performance improves over time due to participants gaining experience or familiarity with a task.

Carryover Effects

A type of order effect in which the impact of a previous experimental condition or treatment continues to influence a participant's response in subsequent conditions.

Straightforward Manipulation

Manipulating an independent variable by presenting different instructions or stimulus materials to participants.

Staged Manipulation

Manipulating an independent variable by creating a specific situation or series of events (a 'stage') to illicit a particular psychological state or behavior from participants, often involving confederates.

Moral Principles (in research ethics)

Fundamental guidelines that govern ethical research conduct, including weighing risks against benefits, acting responsibly and with integrity, seeking justice, and respecting people's rights and dignity.

Weighing Risks Against Benefits (Moral Principle)

An ethical principle requiring researchers to ensure that the potential benefits of a study outweigh the potential risks to participants.

Acting Responsibly and with Integrity (Moral Principle)

An ethical principle that emphasizes researchers' obligation to be truthful, transparent, and accountable for their professional conduct and research findings.

Seeking Justice (Moral Principle)

An ethical principle requiring fair treatment and distribution of both the benefits and burdens of research across different groups of people.

Respecting People's Rights and Dignity (Moral Principle)

An ethical principle that underscores the importance of autonomy, informed consent, privacy, and protecting vulnerable populations in research.

Belmont Report

A foundational document outlining basic ethical principles and guidelines for research involving human subjects, including respect for persons, beneficence, and justice.

Threats to Internal Validity

Alternative explanations for an observed effect that make it difficult to conclude that the independent variable caused the change in the dependent variable.

Maturation (Threat to Internal Validity)

Changes in participants over time due to natural development or spontaneous improvement/decline, rather than the experimental manipulation.

History (Threat to Internal Validity)

External events that occur during the course of a study and affect participants in one condition differently than those in another condition.

Demand Characteristics (Threat to Internal Validity)

Cues in an experiment that inadvertently communicate to participants how the researcher expects them to behave, leading them to alter their responses.

Design Confounds (Threat to Internal Validity)

When an experimenter's mistake in designing the independent variable causes a second variable to covary systematically with the independent variable, providing an alternative explanation for results.

Instrumentation (Threat to Internal Validity)

When the measurement tool or procedures change over time, affecting how the dependent variable is recorded or interpreted.