rm

Laboratory Experiment

A controlled experiment where the IV is manipulated to observe effects on the DV

Strengths of Laboratory Experiment

High control, replicable, eliminates extraneous variables, reliable

Weaknesses of Laboratory Experiment

Low ecological validity, demand characteristics

Field Experiment

Experiment where the IV is manipulated in a natural setting

Strengths of Field Experiment

High ecological validity, fewer demand characteristics

Weaknesses of Field Experiment

Less control, ethical issues (e.g. no consent, deception)

Quasi Experiment

Experiment where the IV already exists and is not directly manipulated

Strengths of Quasi Experiment

Enables study of unethical/impractical variables, high ecological validity

Weaknesses of Quasi Experiment

Hard to control variables, low replicability

Structured Observation

Uses pre-defined behavioural categories to record data

Strengths of Structured Observation

Reliable, repeatable, can be re-analysed with video

Weaknesses of Structured Observation

Low validity, limits behaviour categories

Unstructured Observation

Observer records all behaviour without predefined categories

Strengths of Unstructured Observation

Rich detail, flexible data collection

Weaknesses of Unstructured Observation

Subjective, inconsistent, time-consuming

Self-Report

Any method involving participants reporting their own feelings, attitudes, or beliefs

Questionnaire

Written method using open/closed questions, Likert scales, and rating scales

Strengths of Questionnaires

Quick, cost-effective, standardised, quantitative/qualitative data

Weaknesses of Questionnaires

Lacks validity, social desirability bias, may be misunderstood

Interview

Spoken method where interviewer asks participant questions

Open Questions

Participants give their own answers without pre-set options

Closed Questions

Participants select from pre-determined options

Rating Scales

Participants rate an item on a numeric scale

Likert Scales

Measure attitudes with agree/disagree responses

Semantic Differentials

Participants rate between two opposite adjectives

Structured Interview

Standardised questions asked in the same order

Unstructured Interview

Free-flowing conversation with flexible questions

Semi-Structured Interview

Some set questions, with flexibility to explore answers

Opportunity Sampling

Using participants who are readily available

Random Sampling

All members of target population have equal chance of selection

Volunteer Sampling

Participants self-select to be involved

Snowball Sampling

Participants recruit others for the study

Correlation

Measures relationship between two variables without manipulating them

Positive Correlation

Both variables increase together

Negative Correlation

One variable increases while the other decreases

Zero Correlation

No relationship between the variables

Nominal Data

Data in categories, e.g., colours or names

Ordinal Data

Data ordered but not equally spaced, e.g., race positions

Interval Data

Data with equal intervals but no true zero, e.g., temperature

Ratio Data

Data with equal intervals and a true zero, e.g., height, weight

Internal Validity

The degree to which the results are due to the IV and not other factors

External Validity

Extent to which results can be generalised to other situations

Reliability

Consistency of results across time, observers, or items

Test-Retest Reliability

Consistency of results over time

Independent Measures Design

Different participants are used in each condition of the experiment

Strengths of Independent Measures

No order effects, less demand characteristics

Weaknesses of Independent Measures

Participant variables differ, less economical

Repeated Measures Design

Same participants used in all conditions of the experiment

Strengths of Repeated Measures

Controls participant variables, more economical

Weaknesses of Repeated Measures

Order effects, demand characteristics

Matched Pairs Design

Different but similar participants are used in each condition

Strengths of Matched Pairs

Reduces participant variables and order effects

Weaknesses of Matched Pairs

Hard to match participants, less economical

Counterbalancing

Alternating the order of conditions to control for order effects

Null Hypothesis

Predicts no effect or relationship between variables

Experimental Hypothesis

Predicts an effect or difference caused by the IV

Correlational Hypothesis

Predicts a relationship between variables

One-Tailed Hypothesis

Predicts the direction of the effect

Two-Tailed Hypothesis

Predicts an effect without specifying the direction

Type I Error

Rejecting a true null hypothesis (false positive)

Type II Error

Accepting a false null hypothesis (false negative)

Chi-Square Test

Used for nominal data and independent measures

Mann Whitney U Test

Used for ordinal data, independent groups

Wilcoxon Test

Used for ordinal data, repeated measures

Sign Test

Used for nominal data and repeated measures

Spearman's Rho

Used to find correlation between ordinal variables

Pearson's Correlation

Used to find correlation between interval/ratio variables

Bar Chart

Used for categorical data, bars do not touch

Pie Chart

Circular graph representing proportions

Histogram

Used for continuous data, bars touch

Line Graph

Used to show trends over time or frequencies

Scatter Graph

Used to show correlation between two variables

Abstract

Summary of the whole study including aim, method, and findings

Introduction

Explains background theory and states the hypothesis

Method

Detailed procedure so the study can be replicated

Results

Presents descriptive and inferential statistics

Discussion

Explains findings, compares to previous research, mentions limitations

Conclusion

Summarises findings and links back to the aim

References

List of all sources cited using Harvard referencing

Appendices

Includes raw data, consent forms, calculations, etc.

Peer Review

Evaluation of research by experts before publication

Problems of Peer Review

Bias, plagiarism, falsification, fabrication

Falsifiability

Ability to prove a hypothesis false

Replicability

Ability to repeat the study with consistent results

Objectivity

Research is unbiased and based on facts

Cause and Effect

Demonstrates that changes in IV cause changes in DV

Induction

Drawing general theories from observations

Deduction

Testing theories by collecting evidence

Standardisation

Keeping procedures the same for all participants

Quantifiable Methods

Using numerical data to analyse results

Informed Consent

Participants must be fully informed before agreeing to take part

Right to Withdraw

Participants can leave the study at any time

Confidentiality

Participant data must be kept private

Protection from Harm

Participants should not be put at risk

Debrief

Participants are fully informed about the study afterwards

Deception

Participants should not be misled without justification