Designing Research » Review and Practice - Research Design

What you'll learn this session

Study time: 30 minutes

How to identify and evaluate different research designs in psychology
The strengths and limitations of experimental, correlational and observational methods
How to select appropriate research designs for different psychological questions
Practical considerations when designing psychological research
How to apply your knowledge to exam-style questions

Understanding Research Design in Psychology

Research design is like the blueprint for a psychological study. It's the plan that outlines how you'll collect and analyse data to answer your research question. Choosing the right design is crucial - it's a bit like picking the right tool for a job!

Key Definitions:

Research design: The overall plan and structure of an investigation used to answer a research question.
Variables: Factors or characteristics that can be measured and can change or vary.
Validity: The extent to which a study measures what it claims to measure.
Reliability: The consistency of a measure - whether it produces the same results when repeated.

🔬 Experimental Designs

Experiments involve manipulating variables to establish cause and effect relationships. The researcher changes one variable (independent variable) and measures its effect on another (dependent variable).

Types:

Laboratory experiments: Conducted in controlled settings
Field experiments: Conducted in real-world settings
Natural experiments: When the IV occurs naturally

📊 Non-Experimental Designs

These designs don't manipulate variables but observe relationships or behaviours as they naturally occur.

Types:

Correlational studies: Measure relationship between variables
Observational studies: Record behaviour without intervention
Case studies: In-depth investigation of an individual or group

Experimental Methods in Detail

Experiments are the gold standard in psychology because they allow researchers to establish cause and effect. Let's look at the different experimental designs:

👥 Independent Groups

Different participants in each condition

Strengths: No order effects

Limitations: Individual differences between groups

👤 Repeated Measures

Same participants in all conditions

Strengths: Controls individual differences

Limitations: Order effects possible

👪 Matched Pairs

Participants matched on key characteristics

Strengths: Controls individual differences and order effects

Limitations: Difficult to match perfectly

Case Study Focus: Loftus and Palmer (1974)

This famous experiment investigated how language can affect memory. Participants watched videos of car accidents and were asked questions using different verbs (e.g., "How fast were the cars going when they smashed/hit/contacted each other?"). The verb used affected participants' speed estimates, showing how memory can be influenced by post-event information.

Research design: Laboratory experiment with independent groups design

IV: The verb used in the question

DV: Estimated speed of the cars

Correlational Research

Correlational studies look at relationships between variables without manipulating them. They tell us if variables are related but not if one causes the other.

👍 Strengths

Can study variables that can't be manipulated ethically
Can identify relationships that warrant further investigation
Often uses naturally occurring data
Can study multiple variables at once

👎 Limitations

Cannot establish cause and effect
Correlation doesn't equal causation
May be affected by third variables
Doesn't explain why variables are related

Remember: Correlation coefficients range from -1 to +1:

+1 = Perfect positive correlation
0 = No correlation
-1 = Perfect negative correlation

Observational Methods

Observational studies involve watching and recording behaviour without intervening. They're useful for studying behaviour in natural settings.

👀 Types of Observation

Naturalistic: Observing in natural settings
Controlled: Observing in controlled environments
Participant: Observer takes part in the activity
Non-participant: Observer watches but doesn't participate
Covert: Participants don't know they're being observed
Overt: Participants know they're being observed

📝 Recording Methods

Event sampling: Recording each occurrence of a specific behaviour
Time sampling: Recording behaviour at set time intervals
Behavioural categories: Using a checklist of predefined behaviours
Rating scales: Assessing behaviour on a numerical scale

Ethical Considerations in Research Design

All psychological research must follow ethical guidelines. Key principles include:

Informed consent: Participants must understand what they're agreeing to
Right to withdraw: Participants can leave the study at any time
Protection from harm: Physical and psychological wellbeing must be protected
Confidentiality: Participant data must be kept private
Deception: Should be avoided or justified and followed by debriefing

Choosing the Right Research Design

When planning research, you need to consider several factors to choose the most appropriate design:

❓ Research Question

What are you trying to find out?

Cause-effect questions → Experiments

Relationship questions → Correlational

Behaviour in context → Observational

💼 Practical Issues

What resources do you have?

Time constraints

Available participants

Equipment and funding

Access to settings

⚖ Ethical Considerations

Can you study this ethically?

Potential for harm

Need for deception

Vulnerable populations

Privacy concerns

Applying Your Knowledge: Evaluation Skills

In exams, you'll need to evaluate research designs. Use these points to help structure your answers:

Validity: Does the design measure what it claims to measure?
Reliability: Would the results be consistent if repeated?
Generalisability: Can the findings be applied to other people/settings?
Ethics: Does the design respect participants' rights and wellbeing?
Practicality: Is the design feasible in terms of time, cost and resources?

Exam Tip: PEEL Paragraphs

When evaluating research designs in exam answers, use the PEEL structure:

Point: State your evaluation point clearly
Evidence: Support with evidence or examples
Explain: Explain why this is a strength or limitation
Link: Connect back to the question

Example: "Laboratory experiments have high control over variables (P). For instance, researchers can standardise instructions and control extraneous variables (E). This increases internal validity, meaning we can be more confident that changes in the DV are caused by the IV (E). This makes lab experiments appropriate for investigating cause and effect relationships in psychology (L)."

Practice Application

Think about which research design would be most appropriate for these research questions:

Does listening to music affect memory performance?
Is there a relationship between hours spent on social media and self-esteem?
How do children interact with peers in playground settings?
Does cognitive behavioural therapy reduce symptoms of anxiety?

Remember: There's no perfect research design - each has strengths and limitations. The best design depends on your specific research question, practical constraints and ethical considerations.

🧠 Test Your Knowledge!