2022 Oct/Nov · Paper 22 · Q1 (a, b)2 marksAims and hypotheses
2022 Oct/Nov · Paper 22 · Q8 (a(i))2 marksOperationalising variables
2022 Oct/Nov · Paper 22 · Q9 (c, d)4 marksParticipant and situational variables
2022 May/June · Paper 22 · Q3 (a, b(i))4 marksParticipant and situational variables
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school. “Paper 42” means Paper 4, variant 2.
Practice questions
Original questions written by HomiLabs in the style of the exam, with answers and mark schemes. They are not
Cambridge past paper questions and have not been reviewed by Cambridge. Try each one before opening the answer.
Q1Operationalising variables · Core · Paper 2 style · 4 marks
(a)Explain what is meant by 'operationalising' a variable.[2]
(b)A hypothetical field experiment at a bus station in Lahore tests whether people are more helpful when the person asking is smiling. Suggest how 'helpfulness' could be operationalised.[2]
Show answer
(a) Defining a variable precisely in terms of how it will be manipulated or measured, so that it can be tested and the study repeated.
(b) Whether the passer-by stops and gives directions to the bus stand within 10 seconds of being asked (recorded as helped / did not help).
1 mark for a measurable behaviour; 1 mark for precise detail (time limit / what counts).
Q2Operationalising variables · Core · Paper 2 style · 4 marks
(a)A hypothetical study asks students how anxious they feel before a mathematics test. Write a rating scale question to measure anxiety. Your scale must have labelled anchors.[2]
(b)Give one weakness of measuring anxiety in this way.[2]
Show answer
(a) 'How anxious do you feel right now about the test? Circle one number: 1 = not at all anxious, 2, 3, 4, 5 = extremely anxious.'
1 mark for a question with a numbered scale; 1 mark for labelled anchors at both ends.
(b) Students may give socially desirable answers (e.g. boys under-reporting anxiety), so the score may not reflect their real anxiety.
1 mark weakness; 1 mark explanation in context.
Q3Operationalising variables · Core · Paper 2 style · 4 marks
(a)In a hypothetical experiment, students in Nairobi either listen to music or work in silence while learning a list of 30 words. Suggest how the dependent variable 'memory' could be operationalised.[2]
(b)Suggest how the independent variable could be operationalised.[2]
Show answer
(a) The number of words (out of 30) correctly written down in 3 minutes of free recall immediately after the learning period.
1 mark: number of words recalled; 1 mark: detail (out of 30 / time limit / spelling rule).
(b) Music condition: an instrumental piece played through headphones at the same volume for the 5-minute learning period; silence condition: the same headphones worn with no sound.
1 mark for each condition clearly defined.
Q4Operationalising variables · Core · Paper 2 style · 4 marks
(a)A hypothetical study states: 'The dependent variable is how happy people feel after exercising.' Explain why this variable has not been operationalised.[2]
(b)Rewrite the dependent variable so that it is operationalised.[2]
Show answer
(a) It does not say how happiness will be measured (no scale, score or behaviour), so another researcher could not repeat the measurement in the same way.
(b) The score from 1 (very unhappy) to 7 (very happy) that each participant circles on a mood scale 5 minutes after finishing a 20-minute walk.
1 mark measure; 1 mark timing / anchors.
Q5Operationalising variables · Standard · Paper 2 style · 6 marks
(a)A researcher plans a hypothetical observation of aggression among children in a school playground in Rawalpindi. Suggest two behavioural categories for 'physical aggression' and two for 'verbal aggression'.[4]
(b)Explain why the categories need to be operationalised before the observation starts.[2]
Show answer
(a) Physical: pushing another child with one or both hands; kicking another child. Verbal: calling another child a rude name; shouting a threat such as 'I'll hit you'.
1 mark for each clearly observable, operationalised category (vague terms such as 'being mean' get 0).
(b) So that every observer records the same behaviours in the same way, which improves inter-observer reliability and makes the data objective.
1 mark: consistency between observers; 1 mark: reliability / objectivity.
Q6Operationalising variables · Standard · Paper 2 style · 4 marks
(a)A hypothetical study investigates sleep quality among night-shift nurses in Karachi. Describe one objective and one subjective way of operationalising 'sleep quality'.[4]
Show answer
(a) Objective: a wrist activity monitor records the number of minutes of sleep and the number of awakenings each night for a week. Subjective: each morning nurses rate 'How well did you sleep?' on a scale from 1 (very badly) to 10 (very well).
2 marks each: 1 for the method, 1 for precise measurement detail.
Q7Operationalising variables · Standard · Paper 2 style · 6 marks
A hypothetical experiment tests whether background traffic noise affects concentration. Each participant proofreads a page of text containing 40 planted spelling errors, once in a quiet room and once with recorded traffic noise. They have 10 minutes for each page.
(a)Explain how the researcher has operationalised 'concentration'.[2]
(b)One participant found 34 errors in the quiet condition and 26 in the noisy condition. Calculate the percentage of errors found in each condition.[2]
(c)Suggest one problem with this way of measuring concentration.[2]
Show answer
(a) Concentration is measured as the number of planted errors (out of 40) correctly found in the 10-minute proofreading task.
1 mark: number of errors found; 1 mark: out of 40 / in 10 minutes.
(b) Quiet: 85%; noisy: 65%.
34 ÷ 40 × 100 = 85% (1); 26 ÷ 40 × 100 = 65% (1).
(c) Finding errors also depends on reading and spelling ability, not only concentration, so it may lack validity (or participants may remember error positions if the same passage is reused).
1 mark problem; 1 mark explanation.
Q8Operationalising variables · Standard · Paper 2 style · 6 marks
(a)A hypothetical study tests whether a breathing exercise reduces stress before a driving test in Dubai. Suggest how stress could be operationalised physiologically and by self-report.[4]
(b)Explain one advantage of using both measures.[2]
Show answer
(a) Physiological: heart rate in beats per minute measured with a finger pulse monitor for one minute just before the test. Self-report: 'How stressed do you feel?' on a 0–10 scale where 0 = completely calm and 10 = extremely stressed.
2 marks each: method + unit/scale detail.
(b) If both measures show the same pattern, the researcher can be more confident the result is valid (triangulation); the self-report also shows how the person feels, which heart rate cannot.
1 mark advantage; 1 mark explanation.
Q9Operationalising variables · Standard · Paper 2 style · 6 marks
(a)A researcher in Singapore wants to measure how long teenagers spend on social media each day. Describe two ways of operationalising this variable.[4]
(b)Explain which way is more likely to be reliable.[2]
Show answer
(a) 1) Read the phone's screen-time report for social media apps, recorded in minutes per day averaged over 7 days. 2) Ask the teenager: 'On a normal school day, about how many minutes do you spend on social media?' recorded as a number of minutes.
2 marks each: method + unit/time period.
(b) The screen-time report, because it is recorded automatically and the same each time it is checked, whereas teenagers' estimates may change from one occasion to the next and depend on memory.
1 choice; 1 reason.
Q10Operationalising variables · Standard · Paper 2 style · 4 marks
(a)A hypothetical observation at a farm in Punjab investigates play in young goats. Suggest two operationalised behaviour categories for 'play'.[2]
(b)Describe how the researcher could use time sampling to record these behaviours.[2]
Show answer
(a) Jumping with all four feet leaving the ground at once; head-butting another kid gently without injury (no chasing away afterwards).
1 mark each clearly observable category.
(b) Every 30 seconds for 20 minutes, the observer looks at a focal goat and records which category (if any) it is showing at that moment, giving 40 observations per goat.
1 mark: record at fixed intervals; 1 mark: detail of interval and duration.
Q11Operationalising variables · Challenge · Paper 2 style · 6 marks
(a)A hypothetical study investigates whether volunteers at a charity in Manchester have higher empathy than non-volunteers. Describe how 'empathy' could be operationalised in two different ways.[4]
(b)Explain which of your two ways would give more valid data.[2]
Show answer
(a) 1) Self-report: a questionnaire of 10 statements (e.g. 'I feel upset when I see someone in pain') each rated 1–5 from 'strongly disagree' to 'strongly agree', giving a total score out of 50. 2) Behavioural/task: the number of correct emotions identified when shown 20 photographs of faces, or whether the participant offers help when a researcher 'accidentally' drops a pile of papers.
2 marks each: method + precise scoring.
(b) The behavioural measure may be more valid because it records what people actually do and is less affected by social desirability, which is likely to be strong for a quality such as empathy in charity volunteers.
1 mark choice; 1 mark justification (accept the reverse with a good reason).
Q12Operationalising variables · Challenge · Paper 2 style · 4 marks
(a)A hypothetical field experiment tests whether pupils obey a teacher more when the teacher wears a formal suit than casual clothes. The teacher asks each pupil to pick up a piece of litter. Operationalise 'obedience' so that it could be recorded reliably.[3]
(b)Explain one way the operationalisation of the IV could be standardised.[1]
Show answer
(a) Obedience = the pupil picks up the litter and puts it in the bin within 15 seconds of the instruction, without the instruction being repeated. Recorded as obeyed / did not obey.
1 mark: specific behaviour; 1 mark: time limit; 1 mark: clear rule for what does not count (repeated request, partial compliance).
(b) The same teacher wears the same dark suit and tie (formal) or the same jeans and T-shirt (casual) on every trial.
1 mark.
Q13Operationalising variables · Challenge · Paper 2 style · 4 marks
A hypothetical experiment tests whether caffeine improves reaction time. The IV is operationalised as either 3 mg of caffeine per kilogram of body mass, dissolved in a fruit drink, or the same fruit drink with no caffeine.
(a)Calculate the caffeine dose a participant of mass 72 kg would receive.[1]
(b)A drink contains 80 mg of caffeine per can. Calculate how many cans' worth of caffeine the 72 kg participant receives. Give your answer to 1 decimal place.[1]
(c)Explain why the researcher operationalised the IV as a dose per kilogram rather than giving everyone the same amount.[2]
Show answer
(a) 216 mg
3 × 72 = 216 mg.
(b) 2.7 cans
216 ÷ 80 = 2.7.
(c) The same amount would have a stronger effect on lighter people than heavier people, which would be a participant variable; a dose per kilogram makes the effect more equal across participants, so differences in the DV are more likely due to caffeine itself.
1 mark: body mass affects the effect; 1 mark: controls a participant variable / improves validity.
Q14Participant and situational variables · Core · Paper 2 style · 3 marks
(a)Explain what is meant by a 'participant variable'.[1]
(b)A hypothetical experiment compares two methods of teaching reading to children in Hyderabad, using two different groups. Give two participant variables that could affect the results.[2]
Show answer
(a) A characteristic of an individual participant, such as age, intelligence or personality, that could affect the DV.
1 mark.
(b) Children's existing reading ability; their age / how much English is spoken at home.
1 mark each, must be plausible for reading.
Q15Participant and situational variables · Core · Paper 2 style · 4 marks
(a)A hypothetical laboratory experiment tests whether noise affects mental arithmetic. Identify two situational variables that should be controlled.[2]
(b)Explain how one of these could be controlled.[2]
Show answer
(a) Room temperature; time of day the test is taken (also accept lighting, instructions, the experimenter).
1 mark each.
(b) Test all participants in the same room with the air conditioner set to 22 °C so temperature cannot explain differences in arithmetic scores.
1 mark method; 1 mark explanation.
Q16Participant and situational variables · Core · Paper 2 style · 4 marks
(a)For each of the following, state whether it is a participant variable or a situational variable:(i) a participant's handedness(ii) the brightness of the lighting in the testing room(iii) the friendliness of the experimenter(iv) how tired the participant was before arriving[4]
Show answer
(a) (i) participant (ii) situational (iii) situational (iv) participant
1 mark each.
Q17Participant and situational variables · Standard · Paper 2 style · 4 marks
(a)Explain why participant variables are a particular problem in an independent measures design.[2]
(b)Describe how random allocation could reduce this problem.[2]
Show answer
(a) Different people are in each condition, so a difference in the DV could be caused by differences between the groups (e.g. one group being more able) rather than by the IV.
1 mark: different people in each condition; 1 mark: confounds the result.
(b) Put each participant's name on a slip, mix the slips in a box and draw them out, putting alternate names in condition A and B, so every participant has an equal chance of being in either group and participant variables should be spread evenly.
1 mark method; 1 mark how it helps.
Q18Participant and situational variables · Standard · Paper 2 style · 4 marks
(a)A hypothetical field experiment in a market in Karachi tests whether shoppers are more likely to take a free leaflet from a smiling or a neutral-faced researcher. Explain two situational variables that would be hard to control.[4]
Show answer
(a) 1) Crowding – on busy days shoppers may hurry past and take fewer leaflets regardless of facial expression. 2) Weather – heat or rain may change how willing shoppers are to stop. These could vary between the conditions and confound the results.
2 marks each: variable + effect in context.
Q19Participant and situational variables · Standard · Paper 2 style · 6 marks
(a)Describe participant variables and situational variables, using any examples.[6]
Show answer
(a) Participant variables are characteristics of the people taking part that might affect the DV, e.g. age, IQ, gender, mood, prior experience. They matter mainly in independent measures designs and are controlled by random allocation, matched pairs or repeated measures. Situational variables are features of the environment or procedure, e.g. noise, temperature, time of day, instructions, experimenter's behaviour. They are controlled by standardisation – keeping these features the same for every participant.
Up to 3 marks each: definition (1), example (1), how controlled / why a problem (1).
Q20Participant and situational variables · Standard · Paper 2 style · 4 marks
(a)In a hypothetical experiment, a male researcher tested participants in the morning and a female researcher tested participants in the afternoon. Explain why this is a problem.[2]
(b)Suggest how this could be avoided.[2]
Show answer
(a) The researcher is a situational variable that changes with the condition/time, so any difference could be caused by the researcher (or the time of day) rather than the IV – it is a confounding variable.
(b) Use one researcher for all participants, testing at the same time of day, or have each researcher test equal numbers in each condition and read from the same script.
1 mark suggestion; 1 mark detail.
Q21Participant and situational variables · Standard · Paper 2 style · 6 marks
(a)A hypothetical online experiment lets participants in Pakistan and Canada complete a memory task at home at any time. Explain two situational variables that the researcher cannot control.[4]
(b)Suggest one way to reduce the effect of one of these variables.[2]
Show answer
(a) 1) Time of day – some do it late at night when tired, others in the morning, which affects memory. 2) Distractions – family noise, television or phone notifications may interrupt some participants, lowering their scores.
2 marks each: variable + effect.
(b) Ask participants to complete the task between 9 am and 12 noon local time, in a quiet room with their phone switched off, and record the time from the website.
1 mark suggestion; 1 mark detail.
Q22Participant and situational variables · Challenge · Paper 2 style · 5 marks
A hypothetical experiment with 40 students in a college in Kuala Lumpur compares two revision techniques (flashcards and re-reading) on a French vocabulary test.
(a)Explain how a matched pairs design could be used to control participant variables in this study.[3]
(b)State how many participants would be in each condition.[1]
(c)Suggest one participant variable that matching on the pre-test would not control.[1]
Show answer
(a) Give all 40 students a vocabulary pre-test; rank them by score; pair the top two, the next two and so on; then randomly put one member of each pair into the flashcard group and the other into the re-reading group. The groups then have similar starting ability.
1 mark pre-test on a relevant variable; 1 mark pairing; 1 mark random allocation within pairs.
(b) 20
40 ÷ 2 = 20.
(c) Motivation to revise / amount of revision done at home.
1 mark.
Q23Participant and situational variables · Challenge · Paper 2 style · 6 marks
A hypothetical study compares memory scores of people using a memory-training app with people using a paper workbook. Participants chose which method to use. Their ages (years) were:App group: 19, 21, 23, 20, 28Paper group: 35, 41, 30, 38, 40
(a)Calculate the mean age of each group. Give your answers to 1 decimal place.[2]
(b)Using your answers, explain why the researcher cannot conclude that the app caused better memory scores.[3]
(c)Suggest how the design could be improved.[1]
Show answer
(a) App group: 22.2 years; paper group: 36.8 years.
(b) The app group was about 14.6 years younger on average; age is a participant variable that is linked to memory and familiarity with apps, so it is a confounding variable – the younger age, not the app, may explain the better scores.
1 mark: groups differ in age (with numbers); 1 mark: age could affect memory/app use; 1 mark: confounding variable so cause unclear.
(c) Randomly allocate participants to conditions, or match pairs on age.
1 mark.
Q24Aims and hypotheses · Core · Paper 2 style · 4 marks
(a)A hypothetical experiment tests whether students in Peshawar who sleep for at least 8 hours remember more facts than students who sleep for less than 5 hours. Write a directional (one-tailed) hypothesis for this study.[2]
(b)Write a null hypothesis for this study.[2]
Show answer
(a) Students who sleep for at least 8 hours will recall more facts (out of 20) the next morning than students who sleep for less than 5 hours.
1 mark: direction stated; 1 mark: both IV levels and operationalised DV.
(b) There will be no difference in the number of facts recalled the next morning by students who sleep at least 8 hours and those who sleep less than 5 hours; any difference will be due to chance.
1 mark: no difference; 1 mark: IV and DV included.
Q25Aims and hypotheses · Standard · Paper 2 style · 4 marks
A hypothetical field experiment in Cairo records whether drivers stop at a zebra crossing for a pedestrian who is either a child or an elderly person.
(a)Write a non-directional (two-tailed) hypothesis for this study.[2]
(b)Suggest why the researcher might choose a non-directional hypothesis.[2]
Show answer
(a) There will be a difference in the number of cars that stop (out of 100) for a pedestrian waiting at the crossing depending on whether the pedestrian is a child or an elderly person.
1 mark: difference without direction; 1 mark: IV and DV clear.
(b) Previous research does not clearly predict which pedestrian will receive more help – drivers might stop more for a child (seen as vulnerable) or for an elderly person – so the direction cannot be predicted.
1 mark: no clear previous research / contradictory findings; 1 mark: linked to context.
Q26Aims and hypotheses · Standard · Paper 2 style · 5 marks
(a)Explain the difference between an aim and a hypothesis.[2]
(b)A hypothetical study investigates whether players of fast action video games have quicker reaction times than non-players. Write an aim for this study.[1]
(c)Write a directional hypothesis for the same study.[2]
Show answer
(a) An aim is a general statement of what the study intends to investigate; a hypothesis is a precise, testable prediction about the expected result.
1 mark each.
(b) To investigate whether playing fast action video games is related to reaction time.
1 mark.
(c) People who play fast action video games for at least 5 hours a week will have faster mean reaction times (in milliseconds, on a computer test) than people who never play.
1 direction; 1 operationalised variables.
Q27Aims and hypotheses · Challenge · Paper 2 style · 6 marks
A hypothetical study with office workers in Lahore investigates whether longer commuting time is related to lower job satisfaction.
(a)Write a directional hypothesis for this correlational study.[2]
(b)Write a null hypothesis for this study.[2]
(c)Explain why the researcher cannot conclude that commuting causes low job satisfaction.[2]
Show answer
(a) There will be a negative correlation between the number of hours per week employees spend commuting and their job satisfaction score (out of 50).
1 mark: correlation and direction; 1 mark: both co-variables operationalised. Do not credit wording about difference or cause.
(b) There will be no correlation between hours per week spent commuting and job satisfaction score; any relationship found will be due to chance.
1 mark: no correlation; 1 mark: co-variables.
(c) A correlation does not show cause and effect: a third variable (e.g. lower pay meaning people live further away and are also less satisfied) could explain both.
1 mark: correlation not causation; 1 mark: example of a third variable or reverse direction.
Q28Identifying variables · Core · Paper 2 style · 2 marks
A hypothetical experiment in Toronto: one group chews mint gum while learning 25 words; another group does not. Both groups write down as many words as they can remember 10 minutes later.
(a)Identify the independent variable.[1]
(b)Identify the dependent variable.[1]
Show answer
(a) Whether participants chewed gum or not while learning.
1 mark.
(b) The number of words (out of 25) recalled after 10 minutes.
1 mark (must be operationalised for credit).
Q29Identifying variables · Standard · Paper 2 style · 5 marks
A hypothetical experiment in a sports centre in Islamabad allocates participants to sit still, walk slowly or jog, each for 15 minutes. Afterwards each person rates their mood on a scale from 1 (very low) to 10 (very good).
(a)Identify the three levels of the independent variable.[1]
(b)Identify the dependent variable and state how it was measured.[2]
(c)Identify one variable that should be controlled and explain why.[2]
Show answer
(a) Sitting still for 15 minutes, walking slowly for 15 minutes, jogging for 15 minutes.
1 mark for all three.
(b) Mood, measured by the score circled on a 1–10 mood scale (1 = very low, 10 = very good) after the activity.
1 mark DV; 1 mark measurement.
(c) Time of day / temperature – it could affect mood independently of the activity, so it must be kept the same for all conditions.
1 mark variable; 1 mark reason.
Q30Identifying variables · Challenge · Paper 2 style · 4 marks
A hypothetical study collects data from 60 secondary-school pupils in Mumbai on the hours of homework they do per week and their score on the end-of-term science test.
(a)Identify the two co-variables in this study.[2]
(b)Explain why these are called co-variables rather than an independent and dependent variable.[2]
Show answer
(a) Hours of homework per week; score (%) on the end-of-term science test.
1 mark each.
(b) Neither variable is manipulated by the researcher; both are simply measured as they occur, to see whether they change together, so neither can be said to be the cause.
1 mark not manipulated / measured naturally; 1 mark no cause and effect.
Similar questions
Questions that test the same subtopic in different years, grouped so you can work on one skill at a time.
References only: find each question in its paper (official link where available, otherwise through your school).
