Hypotheses, Variables & Research Procedures (AQA GCSE Psychology): Flashcards

The null hypothesis predicts no difference between conditions (or no relationship between co-variables), and is written alongside the alternative hypothesis to allow for the possibility that the IV has no effect on the DV.

The null hypothesis must be the direct opposite of the alternative hypothesis: the same conditions, and the same operationalised DV.

‘There will be no difference in the number of words recalled when memorising with loud music playing compared with memorising in silence.’

‘There will be no relationship between the number of hours of sleep the night before a test and the number of marks scored on the test.’

False.

If there is a difference, the null hypothesis is rejected and the alternative hypothesis is accepted. If there is no difference, the null hypothesis is accepted.

‘There will be no difference in the number of imitative acts of aggression performed by children who observe an aggressive adult model and those who observe a non-aggressive adult model.’

The independent variable is the factor which is changed or manipulated in order to observe the effect it has on the dependent variable.

Whether participants learn a list of 20 words in silence or with loud rock music playing; or whether they complete a jigsaw after 30 minutes of exercise or after none.

Each version of the IV is called a condition.

A condition that acts as a baseline for comparison with the other conditions — such as silence, no exercise, or no model.

False.

In a lab experiment the IV must be manipulated by the researcher. It cannot be naturally occurring.

True.

For example, gender, age, or an event such as a school closing.

The dependent variable is the factor which is measured in the study, to assess the effect of the IV.

The number of items recalled from a list of 20; the time taken in seconds to complete a jigsaw puzzle; or the number of imitative acts of aggression in a 20-minute observation.

The DV must directly measure the effect of that specific IV — if the IV is music vs silence, the DV should be ‘the number of words recalled’, not just ‘memory’.

False.

It is impossible. The DV must be measurable, so it is always recorded as quantitative (numerical) data.

An extraneous variable is any variable other than the IV that could affect the DV.

If they are not controlled, the researcher cannot be sure that the IV caused the change in the DV.

Time of day — some participants are ‘morning people’; temperature — too warm or cold affects performance on the task; and mood.

Psychologists study how human behaviour is affected by various factors, which are called variables.

Whether participants are told that most people lie in police interviews, or are not told anything at all.

Standardisation means keeping the procedure identical for every participant and every condition, apart from the IV itself.

The instructions; the right to withdraw; the briefing and debriefing; the setting; the timings; and the materials.

So that what is said does not act as an extraneous variable — for example, telling one participant to ‘do their best’ but not telling another.

False.

It also includes telling participants about their right to withdraw at any time.

Participants should be tested in the same environment. This is easier to control in a laboratory than, for example, testing people in different coffee shops.

They should be identical, or equivalent in difficulty where the design requires different versions — such as two word lists matched for difficulty, so participants don’t benefit from seeing the same list twice.

Randomisation means using chance to decide key aspects of the design, rather than the researcher deciding, as this reduces bias.

Randomly allocating participants to conditions, such as drawing names from a hat; and deciding the order of items in a word list randomly, so easy or related words don’t cluster together and unfairly help recall.

Chance can still produce unbalanced outcomes — such as one condition ending up mostly female, or a word list with several words starting with the same letter.

False.

Participants experience all conditions, so random allocation is not possible. Researchers use counterbalancing instead.

Counterbalancing is where half the participants complete the conditions in one order — A then B — and the other half in the opposite order — B then A.

Order effects, such as practice and fatigue.

By keeping them constant across all conditions, so they affect every participant equally and cannot explain any difference in the DV — such as running conditions at the same time of day, a constant temperature, and treating participants in the same friendly, neutral way.

When it varies systematically with the IV — for example, all Condition A participants tested in the morning and all Condition B tested in the evening, when time of day is not the IV.

A confounding variable means the researcher can no longer tell whether it was the IV or the confound that caused the change in the DV, so the study can no longer demonstrate cause and effect.

It increases confidence that the IV caused the change in the DV — internal validity.

They allow the study to be replicated; similar results across repeats show the findings are reliable, and let other researchers keep testing the theory — as with Asch’s conformity study, replicated many times in different countries.

Where there is high control there tends to be low validity, particularly ecological validity. The artificial context and tasks can also give rise to demand characteristics.