12 Threats to Internal Validity and Research Concepts

A set of vocabulary flashcards covering key concepts related to internal validity threats and research methodologies.

Basic Research

Research driven by curiosity to expand knowledge, without a practical goal or product in mind.

Practical Research

Research that investigates real-world issues with implications for everyday problems.

Construct Validity

Extent to which a test or instrument accurately measures the conceptual variable.

Internal Validity

Extent to which a research study can confidently claim that changes in the dependent variable were caused by the independent variable.

Design Confound

A second variable that unintentionally varies systematically with the IV.

Selection Effect

Differences between groups may be due to who is in each group from the start.

Order Effect

When the order of tasks or treatments affects the outcomes.

Maturation

Changes in participants over time that affect results.

Attrition

Participants dropping out of the study, which can bias results.

Testing

Taking a test once changes how participants perform later.

Instrumentation

Changes in measurement tools, observer, or procedures during the study.

Demand Characteristics

Participants guessing the study's purpose and responding in a way that confirms the researcher’s expectations.

Placebo Effect

Participants improve simply because they expect treatment to work, even if it has no real effect.

External Validity

How well the results of the study can apply to contexts outside of the study.

Reliability

How consistent a measurement is.

Validity

How accurate a measurement is; it measures what it is supposed to.

Descriptive Research

Research designed to answer questions about the current state of affairs.

Correlational Research

Research that assesses the relationship or association between two or more variables.

Experimental Research

Research that actively creates or manipulates a situation to assess causality.

Type I Error

False positive; rejecting a true null hypothesis.

Type II Error

False negative; failing to reject a false null hypothesis.

Power

The likelihood of detecting a real difference; higher sample size and stronger effect increases it.

Between Subject Design

Different people in each condition to avoid practice/fatigue effect.

Within Subject Design

The same people in all conditions to increase sensitivity.

Mixed Design

Combines between-subject and within-subject designs to efficiently test complex questions.