Variables
What is a dependent variable (DV)?
The variable that is measured to see the effect of the independent variable.
What does “validity” mean?
Whether a study measures what it intends to measure.
What does “reliability” mean?
Consistency of results when repeated.
Differentiate between quantitative and qualitative data.
Quantitative = numbers; Qualitative = words/descriptions.
What are open and closed questions in questionnaires?
Open = free response; Closed = fixed options.
Identify the IV and DV: “Does listening to music affect concentration?”
IV: music or no music; DV: concentration (e.g., number of correct answers).
Define ecological validity.
The extent to which results apply to real-life settings.
What is test-retest reliability?
When the same test gives similar results on two occasions.
Describe opportunity sampling.
Selecting whoever is available at the time.
Name one advantage and one disadvantage of lab experiments.
Adv: High control → reliability; Disadv: Low ecological validity.
What does “standardisation” mean?
Keeping procedures identical for all participants.
A psychologist conducts an experiment on memory in a classroom but uses nonsense words instead of real ones.
Question: Which type of validity might be low, and why?
Ecological validity may be low because remembering nonsense words is not a realistic everyday memory task.
Why does using a standardised procedure improve reliability?
Ensures all participants experience the same conditions = consistency
State one strength and one weakness of volunteer sampling.
Strength: Time efficient; Weakness: May be biased sample.
Why is random allocation important?
It helps reduce participant variable effects.
Give an operational definition for one variable from this study: “Does exercise improve mood?”
Example: Exercise = 30 minutes of jogging; Mood = score on a 10-point happiness scale.
What are demand characteristics?
Cues that lead participants to guess the study’s aim and change behaviour.
Two observers record how many times children share toys during free play. One observer counts 15 sharing acts, while the other counts only 8.
Question: What reliability problem does this study have?
Low inter-rater reliability
A psychologist interviews students about exam stress. One student’s heart rate is recorded, and another student rates how stressed they feel on a scale of 1–10.
Question: Identify which type of data each is and why.
Heart rate = objective & quantitative data (measurable, independent of opinion).
Self-rating = subjective & quantitative data (based on personal perception or opinion).
Give one strength and one weakness of using self-report methods.
Strength: Insight into thoughts/feelings; Weakness: Social desirability bias.
Why is operationalising variables important for reliability and validity?
It ensures other researchers can replicate and accurately measure the same thing.
Suggest one way to improve ecological validity in a lab experiment.
Make the setting or tasks more realistic.
Suggest one way to improve reliability in an experiment.
Use a standardised procedure so all participants experience the experiment in exactly the same way — for example, giving identical instructions and using the same equipment or materials.
A researcher wants to study stress levels of teachers at one local school by sending out an online sign-up form.
Question: What sampling technique is being used?
Sampling technique: Volunteer (self-selecting) sampling.
What is counterbalancing and why is it used?
Alternating condition order to control order effects.