Designing Research » Strengths and Weaknesses of Methods

What you'll learn this session

Study time: 30 minutes

The strengths and weaknesses of different research methods in psychology
How to evaluate laboratory experiments, field experiments and natural experiments
The advantages and limitations of observations, self-reports and correlations
How to choose appropriate research methods for different psychological investigations
How to apply critical thinking to psychological research methods

Introduction to Research Methods in Psychology

Psychologists use different research methods to study human behaviour and mental processes. Each method has its own strengths and weaknesses that make it suitable for different research questions. Understanding these strengths and weaknesses helps researchers choose the most appropriate method for their study.

Key Definitions:

Research method: A technique for collecting data and information to answer a research question or test a hypothesis.
Validity: The extent to which a research method measures what it claims to measure.
Reliability: The consistency of a research method - whether it produces the same results when repeated.
Ethics: The moral principles and standards that guide research with human participants.

Experimental Methods

Experiments involve manipulating variables to establish cause and effect relationships. There are three main types of experiments in psychology.

🔬 Laboratory Experiments

Strengths:

High control over variables - researchers can isolate the variable being tested
Easy to replicate - procedures can be repeated exactly
Establishes cause and effect relationships
Precise measurements can be taken

Weaknesses:

Artificial environment may lead to low ecological validity
Participants might show demand characteristics (changing behaviour because they know they're being studied)
Experimenter bias may influence results
Limited to what can be studied in a lab setting

🌲 Field Experiments

Strengths:

Higher ecological validity as they take place in real-world settings
Participants may behave more naturally
Can still establish cause and effect
Useful for studying behaviours that can't be recreated in a lab

Weaknesses:

Less control over extraneous variables
More difficult to replicate exactly
Ethical issues with informed consent if participants don't know they're in a study
Practical difficulties in setting up and running the experiment

🌍 Natural Experiments

Natural experiments occur when the independent variable changes naturally without researcher intervention.

Strengths:

Studies variables that would be unethical to manipulate (e.g., trauma, disasters)
High ecological validity as they occur in real life
Can provide insights into rare or unusual events

Weaknesses:

No control over variables
Cannot be planned or replicated
Difficult to establish cause and effect due to confounding variables
May involve studying distressing events, raising ethical concerns

Case Study Focus: Loftus and Palmer (1974)

This laboratory experiment investigated how language affects 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 speed estimates.

Strengths demonstrated: Good control of variables, clear cause-effect relationship established.

Weaknesses demonstrated: Artificial task, possible demand characteristics, questions about real-world application.

Non-Experimental Methods

Non-experimental methods don't manipulate variables but observe or measure existing behaviours or relationships.

👀 Observations

Strengths:

High ecological validity
Studies natural behaviour
Useful for behaviours people can't self-report
Can collect rich, detailed data

Weaknesses:

Observer bias may affect recording
Observer effect if participants know they're being watched
Time-consuming and labour-intensive
Ethical issues with privacy and consent

💬 Self-Reports

Strengths:

Can collect large amounts of data quickly
Access thoughts and feelings not observable
Can be anonymous, encouraging honesty
Relatively cheap and easy to administer

Weaknesses:

Social desirability bias (answering to look good)
Relies on honesty and accurate self-awareness
Question wording may influence responses
Misinterpretation of questions possible

📊 Correlations

Strengths:

Studies relationships between variables
Useful when manipulation is unethical
Can suggest areas for experimental research
Can study naturally occurring relationships

Weaknesses:

Cannot establish cause and effect
Third variables may explain relationships
Direction of relationship unclear
May oversimplify complex relationships

Case Studies and Content Analysis

📄 Case Studies

Strengths:

In-depth information about an individual or small group
Useful for rare conditions or unique situations
Can generate hypotheses for further research
Multiple methods can be used (triangulation)

Weaknesses:

Cannot generalise findings to wider population
Researcher bias may influence interpretation
Difficult to replicate
Ethical issues with anonymity and consent

📰 Content Analysis

Strengths:

Can analyse existing materials (media, documents)
Non-reactive - doesn't affect what's being studied
Can study historical or cultural trends
Both qualitative and quantitative analysis possible

Weaknesses:

Subjective interpretation of content
Coding schemes may miss context or nuance
Limited to available materials
Time-consuming for large amounts of data

Choosing the Right Method

When designing research, psychologists need to consider several factors to choose the most appropriate method:

Research question: What are you trying to find out? Some questions require experiments to establish cause and effect, while others might be better suited to observations or correlations.
Practical considerations: Time, money and resources available will affect method choice.
Ethical considerations: Some methods may raise more ethical concerns than others.
Validity concerns: Which method will give the most valid results for your specific question?

Research in Action: Milgram's Obedience Study

Milgram (1963) used a laboratory experiment to study obedience to authority. Participants were ordered to give electric shocks to another person (actually an actor). 65% of participants delivered the maximum shock when ordered to do so.

Method strengths: Controlled environment, clear procedure, measurable behaviour, established cause-effect.

Method weaknesses: Ethical concerns about deception and psychological harm, artificial situation, potential demand characteristics.

This study shows how the choice of method involves trade-offs between scientific rigour and ethical considerations.

Triangulation: Using Multiple Methods

Many psychologists use triangulation - combining different research methods to overcome the weaknesses of any single method. For example:

Using both observations and self-reports to study anxiety
Following up correlational findings with experiments
Combining qualitative and quantitative methods

Triangulation can increase the validity and reliability of findings by providing different perspectives on the same phenomenon.

Summary: Strengths and Weaknesses of Methods

Every research method has its own strengths and weaknesses:

Experiments are excellent for establishing cause and effect but may lack ecological validity.
Observations have high ecological validity but may suffer from observer bias.
Self-reports can access thoughts and feelings but rely on honest and accurate responses.
Correlations can identify relationships but cannot establish causation.
Case studies provide in-depth information but cannot be generalised.

The best research often combines multiple methods to build a more complete understanding of psychological phenomena.

🧠 Test Your Knowledge!