Edexcel GCSE Psychology (1PS0) · Topic 11 · Research methods
Mini-Lesson
Research Methods
This mini-lesson covers Edexcel Research Methods: writing hypotheses and identifying variables, research designs and sampling, ethics, types of data, and how to calculate the mean, median, mode and range.
Work through each screen, answer the questions as you go and collect ⭐ stars. Every fact here is anchored to a named study or theory on the Edexcel GCSE Psychology (1PS0) Research Methods content. Press Start when you're ready.
Research methods · variables
Hypotheses & variables
A hypothesis is a clear, testable prediction.
Independent variable (IV) — what the researcher changes.
Dependent variable (DV) — what the researcher measures.
Extraneous variables — other factors that must be controlled.
A null hypothesis predicts no difference; an alternative hypothesis predicts there will be one.
Quick check
Spot the IV
?A study tests whether caffeine affects reaction time by giving one group caffeine and another water. What is the independent variable?
Research methods · design
Experimental designs & sampling
Designs decide how participants are used:
Independent groups — different people in each condition.
Repeated measures — the same people in every condition.
Matched pairs — different people paired on key traits.
Sampling selects participants: random, opportunity, systematic and stratified are common methods.
Quick check
Which design?
?Different, unrelated groups of people each experience only one condition of an experiment. Which design is this?
Research methods · ethics
Ethical issues
Researchers must protect participants. Key ethical issues include:
Informed consent and the right to withdraw.
Avoiding or justifying deception, followed by a debrief.
Protection from harm and confidentiality.
Sort it
Sort the research terms
Tap a term, then tap the group it belongs to.
⚖️ Ethical issue
🧪 Experimental design
🎯 Sampling method
Calculate
Calculate the mean
#Six reaction times (in seconds) are: 2, 4, 3, 5, 4, 6. Calculate the mean.
s
Hint: add them (2+4+3+5+4+6 = 24) then divide by 6.
Calculate
Find the mode
#A data set is: 5, 3, 5, 8, 5, 2. What is the mode (most frequent value)?
Hint: which value appears most often?
Calculate
Calculate the range
#The highest score is 27 and the lowest is 9. Calculate the range.
Hint: range = highest − lowest = 27 − 9.
Calculate
Work out a percentage
#In a sample, 9 out of 30 participants obeyed. What percentage obeyed?
%
Hint: (9 ÷ 30) × 100.
Match it
Match the method term
Tap a description on the left, then its matching term on the right.
Statement
Answer
Quick check
Types of data
?A researcher writes down participants' descriptions of how they felt, in their own words. This is best described as:
Quick check
Central tendency
?Which measure of central tendency is the middle value when data are put in order?
Recap
The big ideas to know
Variables: IV (changed) · DV (measured) · extraneous (controlled)
Hypotheses: null (no effect) vs alternative
Designs: independent groups · repeated measures · matched pairs
Sampling: random · opportunity · systematic · stratified