Welcome to the "How-To" of Psychology!
Ever wondered how psychologists actually find out why we do the things we do? They don't just guess! They use Research Methods. Think of this chapter as the "Psychologist’s Toolbox." You are going to learn about the different tools researchers use to collect data, how they choose who to study, and how they make sure they are being fair and scientific.
Don’t worry if some of the terms seem a bit "science-y" at first—we will break them down step-by-step with plenty of examples!
1. Self-Reporting: Asking the Right Questions
Self-report is exactly what it sounds like: asking people to tell you about their own thoughts, feelings, or behaviors. The two main tools here are Questionnaires and Interviews.
Questionnaires
These are sets of written questions. They are great because you can send them to hundreds of people at once!
Questions can be:
1. Open Questions: The participant can write whatever they want (e.g., "How do you feel today?"). This gives qualitative data (words).
2. Closed Questions: The participant must choose from set answers (e.g., "Yes/No").
3. Ranked Scale Questions: Participants give a rating (e.g., "On a scale of 1-5, how happy are you?"). This gives quantitative data (numbers).
Interviews
Interviews are face-to-face (or over the phone). There are three main types:
• Structured: You have a list of set questions and you don't deviate. It’s like a spoken questionnaire.
• Unstructured: Like a natural conversation. You have a topic, but the questions change based on what the person says.
• Semi-structured: A mix of both. You have some set questions but can ask follow-up questions if something interesting comes up.
Watch out for: Researcher Effects
This is when the person asking the questions accidentally influences the answer. For example, if an interviewer looks shocked when you admit something, you might change your next answer to sound "nicer."
Key Takeaway
Self-reports are great for finding out what people think, but remember: people might lie to look better (this is called social desirability)!
2. Choosing Your Group: Sampling Techniques
Psychologists usually want to know about a Target Population (like "all teenagers in the UK"), but they can't study everyone! Instead, they pick a smaller Sample.
Common Sampling Methods:
• Random Sampling: Everyone in the population has an equal chance of being picked (like pulling names out of a hat).
• Stratified Sampling: Making sure the sample has the same proportions as the population (e.g., if the population is 60% girls, the sample is 60% girls).
• Volunteer (Self-Selected) Sampling: You put up an ad and people come to you.
• Opportunity Sampling: You just ask whoever is available at the time (e.g., standing in a hallway and asking people walking past).
Memory Aid: The "R-S-V-P" of Sampling
Think Random, Stratified, Volunteer, and Opportunity (Okay, it's RSVO, but close enough to RSVP!).
Quick Review
• Random = Fair but hard to do.
• Opportunity = Easy but might be biased.
• Volunteer = Gets motivated people, but they might be "different" from the average person.
3. The Experiment: Finding Cause and Effect
If you want to prove that one thing causes another, you need an Experiment.
• Independent Variable (IV): The thing the researcher changes (The Cause).
• Dependent Variable (DV): The thing the researcher measures (The Effect).
Types of Experiments
• Laboratory Experiment: Done in a controlled environment. Strength: Very accurate. Weakness: It's an artificial setting, so people might act weirdly.
• Field Experiment: Done in a real-world setting (like a school or street). Strength: Natural behavior. Weakness: Hard to control extraneous variables (distractions like noise or weather).
Experimental Designs (How you group your people)
1. Independent Groups: Group A does Condition 1, Group B does Condition 2.
2. Repeated Measures: Everyone does both conditions. (Watch out for Order Effects—people might get tired or better with practice!).
3. Matched Pairs: You pair up two similar people (same age/IQ) and put one in Group A and one in Group B.
Analogy: The Light Switch
The IV is the light switch (you control it). The DV is the light bulb (it reacts to what you did). Extraneous variables are things like a power cut or a broken bulb that mess up your experiment!
Key Takeaway
Experiments are the only way to say "A caused B." To keep them fair, researchers use Randomisation (picking things by chance) and Counterbalancing (changing the order of tasks) to avoid mistakes.
4. Correlations: Looking for Links
Sometimes you can't do an experiment because it’s unethical or impossible. Instead, you look for a Correlation—a relationship between two "co-variables."
• Positive Correlation: As one goes up, the other goes up (e.g., Revision time and Exam grades).
• Negative Correlation: As one goes up, the other goes down (e.g., Absences from school and Exam grades).
• Zero Correlation: No link at all (e.g., Height and how much you like cheese).
Important Rule: Correlation is NOT Causation!
Just because two things are linked doesn't mean one caused the other. For example, ice cream sales and shark attacks both go up in summer. Does ice cream cause shark attacks? No! The "other variable" is the hot weather.
5. Observations: Watching Behavior
Instead of asking, you just watch. But there are different ways to do it:
• Naturalistic: Watching people in their own environment.
• Structured: Using a "tally" sheet to count specific behaviors.
• Overt: They know you are watching.
• Covert: You are "undercover" or hidden.
• Participant: The researcher joins in with the group.
• Non-participant: The researcher stays on the sidelines.
Quick Tip: Tallying
In Event Sampling, you tick a box every time a behavior happens. In Time Sampling, you only tick a box at set intervals (e.g., every 30 seconds).
6. Ethics: Doing the Right Thing
Psychology is about people (and animals), so we have to be kind. The British Psychological Society (BPS) has rules:
1. Informed Consent: Participants should know what they are signing up for.
2. Deception: You shouldn't lie to people unless absolutely necessary.
3. Right to Withdraw: They can leave whenever they want.
4. Protection from Harm: They shouldn't be stressed or hurt.
5. Confidentiality: Keep their names secret.
Animal Research
When using animals, researchers must follow the Scientific Procedures Act (1986). They must use the smallest number of animals possible and ensure they don't suffer unnecessarily.
7. Data Analysis: Making Sense of the Numbers
Once you have your data, you need to describe it using Descriptive Statistics.
Measures of Central Tendency (Averages)
• Mean: Add them all up and divide by how many there are.
• Median: The middle score when they are in order.
• Mode: The most common score.
Measures of Dispersion (The Spread)
• Range: The difference between the highest and lowest score.
• Standard Deviation: A fancy way of saying "how much do the scores differ from the average?"
The formula for Standard Deviation is: \( \sqrt{\frac{\sum (x - \bar{x})^2}{n - 1}} \)
Inferential Statistics (The "Deep Dive")
Psychologists use math to see if their results happened by chance or if they are significant. You need to know when to use these tests:
• Spearman’s Rho: Used for correlations.
• Mann-Whitney U: Used for experiments with independent groups.
• Wilcoxon: Used for experiments with repeated measures.
• Chi-Squared: Used when looking at frequencies (how many people in a category).
Formula for Chi-Squared: \( \chi^2 = \sum \frac{(o - e)^2}{e} \)
Did you know?
Psychologists usually use a significance level of \( p \leq 0.05 \). This means they are 95% sure the results aren't just a lucky fluke!
8. Is Psychology a Science?
To be a science, research must be:
• Replicable: Can someone else do it again and get the same result?
• Objective: Is it free from personal opinion?
• Reliable: Are the findings consistent?
• Valid: Does it measure what it claims to measure? (e.g., Ecological Validity means "is it like real life?").
• Falsifiable: Can you prove the theory wrong?
Final Encouragement
Research Methods might feel like a lot of definitions, but once you start applying them to the studies (like Milgram or Sherif), it all starts to click! Keep this guide handy and use it to "check off" the methods used in every study you read. You've got this!