IB Psychology HL Paper 3: Research Credibility, Validity, Bias, and Methodology

Credibility

The trustworthiness and believability of a study's findings.

Member Checking

Asking participants to verify the researcher's interpretations of their data.

Pros of Member Checking

Corrects researcher misinterpretations; improves validity.

Cons of Member Checking

Participants might disagree; can be hard to organize.

Triangulation

Cross-checking findings using multiple methods, sources, or researchers.

Data Triangulation

Using different data sources (e.g., interviewing a student, parent, and teacher).

Method Triangulation

Using different research methods (e.g., interviews and observations).

Researcher Triangulation

Using multiple researchers to analyze data.

Theory Triangulation

Using multiple theoretical perspectives to interpret data.

Credibility of the Researcher

The researcher's own trustworthiness. Established by experience, training, and preparation.

Generalizability (Quantitative)

Applying findings to a broader population.

Transferability (Qualitative)

Applying findings to a different context or group.

Target Population

The specific group a study aims to understand (not the 'general population').

External Validity

The extent to which experimental results apply to real-world settings.

Factors Affecting External Validity

Sample Size: Larger samples are often more representative.

Sampling Technique

Random and stratified samples are best for generalizing; opportunity and volunteer samples are weak.

Ecological Validity

How realistic the study's setting and task are. Low validity limits generalization.

Temporal Validity

Whether the findings are still true for a different time period.

Researcher Bias

When a researcher's expectations or beliefs influence the results.

Double-Blind Study

Both researcher and participants don't know the group assignments. The gold standard for avoiding bias.

Single-Blind Study

Only the researcher or the participants are unaware of group assignments.

P-hacking

Unethically manipulating data to get a statistically significant result.

Pre-registration

A modern solution where researchers publicly post their hypothesis and research plan before collecting data to prevent p-hacking.

Participant Bias

When participants act in ways that are not natural due to being in a study.

Demand Characteristics

Cues in a study that hint at its purpose.

Expectancy Effect

Participants act in a way to help the researcher.

Screw-You Effect

Participants act in a way to sabotage the study.

Reactivity

Changing behavior simply because one is being watched.

Social Desirability Bias

Participants give 'socially acceptable' answers to look good.

Placebo Effect

A participant experiences a real change from a fake treatment due to their belief in it.

Order Effects

The order of conditions affects a participant's performance.

Types of Order Effects: Fatigue Effects

Participants get tired or bored.

Types of Order Effects: Interference Effect

A previous task affects performance on the next one.

Types of Order Effects: Practice Effect

Participants improve on a task from repetition.

How to Control Order Effects: Counterbalancing

Varying the order of conditions for different groups of participants.

How to Control Order Effects: Filler Task

A distractor task between conditions to clear short-term memory.

Interviewer Effects

When an interviewer's characteristics (age, gender) or behavior (nodding, tone) influence participant responses.

Acquiescence Bias

A participant's tendency to agree with the interviewer.

How to Control Interviewer Effects:: Standardization

Use a structured interview script.

How to Control Interviewer Effects: Training

Train interviewers to be neutral.

How to Control Interviewer Effects: Matching

Match the interviewer to the participant on key traits (e.g., gender, language).

Types of Demand Characteristics

Expectancy Effect

Screw You Effect

Ractivity

Factors Affecting External Validity:

Sample Size

Sample Technique

Ecological Validity

Temporal Validity

What type of research does "generalizability" apply to?

Quantitative

What type of research does "transferability" apply to?

Qualitative