2025 Cambridge IAS-Level Psychology (9990) Practice Paper with Answers

During the study, the researchers woke the participants up at one of two intervals: either 5 minutes or 15 minutes after the onset of REM sleep. Upon waking, the participants were required to make a forced-choice estimation of whether they had been dreaming for 5 minutes or 15 minutes. This subjective estimation was then compared to the actual physiological duration of REM sleep recorded by the EEG to assess accuracy.

1 mark: Stating the specific intervals used (5 and 15 minutes of REM sleep).
1 mark: Explaining the forced-choice task given to the participants (deciding between 5 or 15 minutes).
0.375 mark: Stating that these subjective choices were compared with the actual duration of REM sleep to verify accuracy.

In Hassett et al., the plush toys used included Raggedy Ann, Winnie the Pooh, and a plush dog. The wheeled toys included a model wagon, a dump truck, and a police car. To record interactions, the monkeys were observed in an outdoor area where the toys were placed, and their behaviors were recorded on video camera. These recordings were later analyzed and coded by human observers.

1 mark: Correctly identifying one plush toy (e.g., Raggedy Ann, Winnie the Pooh, Teddy bear) AND one wheeled toy (e.g., wagon, truck, police car).
1 mark: Describing that the interactions were video recorded (for subsequent analysis).
0.375 mark: Stating that the recorded behavior was later coded by observers (to measure duration/frequency of interactions).

In the training of the elephants, the secondary reinforcer was a high-pitched whistle blow, and the primary reinforcer was food (such as chopped bananas or sugarcane). When the elephant performed the correct target action (e.g., raising a foot), the trainer blew the whistle immediately. This sound was immediately followed by offering the food reward to the elephant, reinforcing the association.

1 mark: Identifying the secondary reinforcer (whistle) and the primary reinforcer (food, such as bananas or sugarcane).
1 mark: Describing that the whistle was blown immediately upon the performance of the correct behavior.
0.375 mark: Describing that the food reward immediately followed the whistle blow to complete the classical conditioning pairing.

The revised version of the Eyes Test introduced several improvements over the original: 1) The number of response choices was increased from two to four (one target and three foils) to reduce the effect of guessing. 2) The target words were changed to ensure they tested complex mental states (e.g., 'insisting') rather than simple emotional states (e.g., 'happy' or 'sad'), and a glossary of terms was provided to ensure participants understood all definitions.

1 mark: Identifying one modification (e.g., changing from 2 to 4 response choices, or increasing the number of items from 25 to 36).
1 mark: Identifying a second modification (e.g., removing basic emotions in favor of complex mental states, or providing a glossary of definitions, or balancing the number of male and female eyes).
0.375 mark: Providing the psychological rationale for one of these modifications (e.g., to reduce the chance of guessing, or to avoid ceiling effects).

In Pozzulo et al., the target-present line-up contained the actual target (the culprit from the video clip) alongside three or five foils. In contrast, the target-absent line-up did not contain the actual target; instead, the target was replaced by a brand-new foil who matched the general physical description. Participants were instructed that the person might not be in the line-up and were explicitly given the choice to state that the culprit was 'not there' or they 'don't know'.

1 mark: Stating that the target-present line-up includes the actual culprit while the target-absent line-up replaces the culprit with a foil.
1 mark: Stating that participants were instructed the target may or may not be present in the line-up.
0.375 mark: Stating that participants were provided with a clear rejection option (e.g., choosing 'not there' or 'don't know').

In the 'ill' victim condition, the victim carried a black cane and acted as if they had collapsed due to illness. In the 'drunk' victim condition, the victim smelled of liquor, carried a bottle wrapped in a brown paper bag, and did not carry a cane. In both conditions, the victims were dressed identically in casual clothing (Eisenhower jackets, old trousers, and no tie) to ensure a controlled comparison.

1 mark: Describing the 'ill' victim condition details (carrying a black cane, appearing sober/ill).
1 mark: Describing the 'drunk' victim condition details (smelling of alcohol, carrying a bottle in a brown paper bag, lacking a cane).
0.375 mark: Mentioning that both victims wore identical casual clothes (e.g., Eisenhower jackets and old trousers) as a control.

The researchers used high-resolution magnetic resonance imaging (MRI) to acquire structural brain scans of the participants. Scans were conducted at two distinct time points: immediately before and immediately after the 8-week mindfulness-based stress reduction (MBSR) program. To calculate changes in brain structure, the researchers utilized voxel-based morphometry (VBM) to perform quantitative analyses of gray matter concentration in specified regions of interest, such as the hippocampus.

1 mark: Explaining that high-resolution MRI scans were taken at two points: before and after the 8-week intervention.
1 mark: Stating that voxel-based morphometry (VBM) was the specific analytical software/technique used to measure gray matter density.
0.375 mark: Identifying a specific region of interest that was measured (e.g., hippocampus, temporoparietal junction, or posterior cingulate cortex).

To instigate mild aggression arousal, the researchers took each child to an anteroom containing highly attractive toys, such as a fire engine, a jet fighter, and a colorful doll set. The child was allowed to play with these toys for about 2 minutes. The experimenter then interrupted the play and told the child that they could no longer play with these toys because they were her very best toys, and that she had decided to reserve them for other children. The child was then told they could play with the toys in the next room instead.

1 mark: Stating that children were first allowed to play with highly attractive/exciting toys (e.g., fire engine, doll set) for a brief period (2 minutes).
1 mark: Describing the experimenter's intervention (stopping the play, stating the toys are 'best' and reserved for other children).
0.375 mark: Explaining that this was done to ensure a uniform level of frustration and to provoke aggressive tendencies before the final observation.

The study by Dement and Kleitman investigated four specific patterns of rapid eye movements (REMs) to see if they corresponded with the content of the dream. These patterns were: mainly vertical, mainly horizontal, mixed (both vertical and horizontal), and little or no movement.

1.1875 marks for each correct pattern identified, up to a maximum of 2.375 marks.
- Accept: mainly vertical / vertical
- Accept: mainly horizontal / horizontal
- Accept: mixed / both vertical and horizontal
- Accept: little or no movement / inactive

In Hassett et al., behavior was coded as either interactive or non-interactive. "Holding" was one of the interactive behaviors and required physical contact (via hands, mouth, or other body parts) while the monkey was not moving (stationary).

1.1875 marks for identifying the physical contact methods (hands, mouth, or body contact).
1.1875 marks for specifying that the animal must be stationary during this contact.

The training targets were medical and husbandry behaviors. The "trunk-up" behavior allowed handlers to check the elephant's oral health. Handlers used positive reinforcement, offering food rewards (primary reinforcers) paired with a whistle (secondary reinforcer/bridge) immediately when the correct response was shown.

1.1875 marks for stating the clinical purpose (to inspect the mouth/throat/teeth).
1.1875 marks for describing the positive reinforcement mechanism (primary/secondary reward, e.g., food combined with a whistle).

Participants in Group 1 were selected based on having a clinical diagnosis from recognized psychiatric manuals (DSM-IV or ICD-10) and were verified to have normal cognitive development and IQ (measured via WAIS-R subtests, showing normal ranges above 85).

1.1875 marks for mentioning formal diagnosis according to diagnostic manuals (DSM-IV or ICD-10).
1.1875 marks for mentioning normal IQ / cognitive functioning (specifically IQ score > 85 or equivalent).

To prevent biased lineups, Pozzulo et al. chose foils that met the general physical description of the targets (e.g., similar hair, face shape). Independent raters evaluated these foils to confirm that they looked sufficiently similar to the target to ensure fair testing conditions.

1.1875 marks for describing physical matching (e.g., hair color, gender, age, basic description).
1.1875 marks for mentioning the use of independent raters or judges to assess/confirm the similarity.

Hölzel et al. carefully screened participants to control for confounding variables. To be included, participants had to be physically and mentally healthy (no psychiatric conditions, no medications), have no prior experience with meditation, and be eligible for safe MRI scanning (no metal implants).

1.1875 marks for each correct exclusion criterion identified, up to a maximum of 2.375 marks.
- Accept: No psychiatric/medical illness
- Accept: No psychotropic/medical drugs
- Accept: No prior meditation/mindfulness experience
- Accept: No contraindications to MRI (e.g., metal implants, claustrophobia)

Milgram created high experimental realism. The generator was built in an instrument laboratory and featured realistic components: 30 toggle switches, 15-volt increments up to 450 volts, printed verbal warnings, mechanical buzzers, and a label plate, convincing participants it was a genuine electrical device.

1.1875 marks for detailing the mechanical/physical features (30 switches, 15V-450V range, buzzers, flashing lights).
1.1875 marks for detailing the specific verbal labels/designations (e.g., "Slight Shock", "Danger: Severe Shock", or "XXX").

To prevent individual differences in aggression from confounding the results, Bandura et al. pre-assessed the children. An experimenter and a teacher who knew the children rated them on four aggressive behaviors on 5-point scales. Children with similar total ratings were grouped into triplets, with one child from each triplet randomly assigned to one of the experimental conditions or the control group.

1.1875 marks for explaining the rating system (using 5-point scales rated by a teacher and experimenter on four specific dimensions of aggression).
1.1875 marks for explaining the matching process (grouping children into triplets of equal scores and randomly assigning one to each condition).

Similarities: 1. Use of Objective Physiological Measurements: Both studies employed highly scientific and objective physiological measurements to investigate psychological phenomena. Dement and Kleitman utilized electroencephalography (EEG) to measure brain wave patterns and electrooculography (EOG) to record rapid eye movements during sleep. Similarly, Hölzel et al. used magnetic resonance imaging (MRI) to obtain high-resolution anatomical scans measuring grey matter concentration. This reliance on biological technology minimized participant and researcher bias. 2. Highly Controlled Environments: Both studies took place in controlled, lab-based environments to rule out extraneous variables. Dement and Kleitman conducted their research in a quiet, dark sleep laboratory and controlled for participant diet by restricting caffeine and alcohol. Hölzel et al. kept scanning parameters identical across pre- and post-tests and utilized a standardized 8-week Mindfulness-Based Stress Reduction (MBSR) course. Differences: 1. Research Design and Intervention: Hölzel et al. used a pre-test/post-test longitudinal design with a treatment and control group to observe structural brain changes over an 8-week period. Dement and Kleitman did not administer a long-term therapeutic intervention, instead focusing on immediate, overnight sleep cycles and immediate dream recall within a correlational/experimental framework. 2. Sample Size and Generalizability: Dement and Kleitman used an extremely small sample of 9 participants (7 males and 2 females), with only 5 studied in intensive detail, reducing the external validity. Hölzel et al. utilized a larger sample of 33 participants (16 in the mindfulness group, 17 in the control group), allowing for a more statistically robust analysis of brain changes across groups.

Level 4 (10-12 marks): Candidate provides a detailed and balanced comparison of both studies, clearly outlining at least one similarity and one difference. The points are thoroughly explained with precise details from both Dement & Kleitman and Hölzel et al. Psychological terminology is used accurately throughout. Level 3 (7-9 marks): Candidate provides a clear comparison. Both similarities and differences are discussed, but one may be significantly more detailed than the other, or there may be minor inaccuracies in the details of the studies. Level 2 (4-6 marks): Candidate discusses only similarities or only differences, or provides a shallow discussion of both with limited study details. Level 1 (1-3 marks): Candidate describes the studies individually with little to no explicit comparison, or makes very basic, unsupported comparative assertions. Level 0 (0 marks): Response is completely irrelevant or not present.

STRENGTHS: 1. Use of Quantitative Data (Required Issue): The study collected objective, numerical data in the form of voxel-based morphometry (VBM) gray matter concentration values and scores from the Five Facet Mindfulness Questionnaire (FFMQ). This quantitative approach allows for direct statistical comparisons between the MBSR and control groups, and pre- vs. post-intervention changes, entirely avoiding subjective interpretation. 2. Standardisation and Control: The research utilized highly standardized procedures. Every participant underwent the same scanning sequence parameters on the same type of MRI scanner, and those in the experimental group received a highly structured 8-week mindfulness-based stress reduction program with identical audio guides. This high level of control increases internal validity by minimizing confounding variables and ensures the study can be easily replicated to test reliability. WEAKNESSES: 1. Sample Biases and Generalisability: The sample consisted of a small group of participants (16 experimental, 17 controls) who were self-selected (recruited via orientation sessions for stress reduction courses). These individuals were already highly motivated to practice mindfulness, meaning they may not represent the general population who might display different neurological changes or lower adherence. 2. Low Ecological Validity of the Scanner: Getting scanned in an MRI machine is a highly unnatural, noisy, and claustrophobic experience. This artificial setting could cause stress or discomfort, which may temporarily affect brain activity or alter normal physiological responses, reducing how well the biological findings represent natural, daily-life states of mindfulness.

Level 4 (8-10 marks): Evaluation is comprehensive and balanced, containing two well-explained strengths (including the compulsory issue of quantitative data) and two weaknesses. The points are thoroughly applied to the Hölzel et al. study using accurate psychological terminology. Level 3 (5-7 marks): Evaluation is detailed but may be slightly unbalanced (e.g., three strong points or lacking some elaboration on one point). The compulsory issue is addressed. Good application to the core study. Level 2 (3-4 marks): Evaluation is basic. Points are identified but lack depth, development, or specific application to the details of Hölzel et al. The compulsory issue may be missed or poorly explained. Level 1 (1-2 marks): Superficial evaluation showing very limited understanding. Only one or two brief points are made, with little or no application to the study. Level 0 (0 marks): No creditworthy response.

Event sampling involves defining specific behavioral categories of interest (e.g., sharing, comforting, cooperating) and recording every single occurrence of these behaviors throughout the observation session. Contrastingly, time sampling only records whether a behavior occurs within specific time intervals (e.g., every 30 seconds). An advantage of event sampling here is that prosocial actions can be infrequent or occur in quick bursts; time sampling might miss these events if they occur outside the observation windows, whereas event sampling ensures every occurrence is counted, providing a more complete tally of the target behaviors.

Max 3.83 marks total: - Up to 2 marks for describing how event sampling would be used: 1 mark: Defining behavioral categories (e.g., sharing, helping). 1 mark: Explaining that every instance of these behaviors is recorded continuously during the observation period. - Up to 1.83 marks for explaining the advantage over time sampling: 1 mark: Identifies an advantage (e.g., does not miss infrequent/brief behaviors). 0.83 marks: Contextualizes the advantage to the scenario of children's prosocial behavior during recess.

Quantitative data is numerical, allowing for objective statistical analysis. In Dement and Kleitman's study, the forced-choice option (5 or 15 minutes) provides a binary numeric outcome that can be compared against the actual duration of REM sleep (measured in minutes). However, a key disadvantage of relying strictly on quantitative data in dream research is the loss of rich, subjective detail. While a participant might correctly identify a dream as lasting 15 minutes, the number itself fails to capture the vividness, emotional intensity, or narrative structure of the dream, which could provide deeper insights into sleep physiology.

Max 3.83 marks total: - Up to 1.83 marks for explaining why it is quantitative: 1 mark: Identifies that it involves numbers/numerical values (5 vs 15 minutes) that can be analyzed statistically. 0.83 marks: Links to the specific measurement (forced-choice estimation of duration). - Up to 2 marks for explaining a disadvantage: 1 mark: Explains that quantitative data lacks descriptive depth/meaning. 1 mark: Contextualizes this to the Dement and Kleitman study (e.g., misses the qualitative content/experience of the dream itself).

To operationalize variables means to turn them into measurable forms. 1. Disgust: The researcher could adapt the 'Feelings Thermometer' used by Saavedra and Silverman. The participant would rate their disgust on a 0-8 scale when handling balloons of different textures or colors. 2. Fear: The researcher could operationalize fear by measuring behavioral avoidance (e.g., the distance in meters the participant stands from an inflated balloon) or physiological responses (such as recording changes in heart rate using a pulse monitor when a balloon is inflated in the room).

Max 3.83 marks total: - Up to 1.91 marks for operationalizing disgust: 1 mark: Clear, measurable indicator (e.g., 0-8 rating scale, verbal disgust statements). 0.91 marks: Linked clearly to the balloon phobia context. - Up to 1.92 marks for operationalizing fear: 1 mark: Clear, measurable indicator (e.g., heart rate, distance of avoidance, fear rating scale). 0.92 marks: Linked clearly to the balloon phobia context.

A directional (one-tailed) hypothesis specifies the expected direction of the effect (e.g., stating which group will perform better or show higher rates of a behavior). A non-directional (two-tailed) hypothesis simply states that a difference/effect will occur, without predicting which group will be higher or lower. In a Milgram-style context: - Directional: 'Participants who are given commands by an experimenter wearing a grey lab coat will obey to a higher voltage level than participants given commands by an experimenter wearing casual clothes.' - Non-directional: 'There will be a significant difference in the maximum voltage of shocks administered by participants who are commanded by an experimenter in a grey lab coat compared to an experimenter in casual clothes.'

Max 3.83 marks total: - Up to 1.83 marks for explaining the conceptual difference: 1 mark: Directional specifies the direction of the expected difference/effect. 0.83 marks: Non-directional predicts a difference/effect but does not state the direction. - Up to 2 marks for the Milgram-related examples: 1 mark: Formulating a valid directional hypothesis in context. 1 mark: Formulating a valid non-directional hypothesis in context.

The qualitative data in Piliavin et al.'s study consisted of spontaneous verbal remarks made by bystanders sitting near the victim (e.g., women saying 'It's a man's job to help' or people saying 'I wish I could help him, but I'm not strong enough'). This qualitative data was essential for explaining the quantitative results (such as the high rates of helping for the cane victim and lower/slower helping for the drunk victim). It revealed the psychological mechanisms behind the behavior—specifically, it showed that passengers were experiencing internal conflict and actively trying to rationalize their lack of intervention or their delay in helping. This supported the cost-benefit model proposed by the researchers to explain why people did or did not help.

Max 3.83 marks total: - 1 mark for identifying the qualitative measure: Verbal comments/remarks made by passengers (or comments made by female passengers specifically). - Up to 2.83 marks for explaining how it helped interpret quantitative findings: 1 mark: Links to a quantitative finding (e.g., helping rates, speed of helping, gender differences in helping). 1 mark: Explains the psychological insight gained (e.g., bystander rationalization, fear, cost-benefit calculation). 0.83 marks: Fully explains the connection between the qualitative comment and the overall cost-benefit model or quantitative pattern.

Self-selected (volunteer) sampling relies on individuals choosing to participate, often in response to an advert. This creates 'volunteer bias'—the participants might share specific traits, such as higher educational background, greater curiosity, more free time, or higher levels of empathy/social interest, which would directly affect their scores on a theory of mind test like the Eyes Test. This makes the sample unrepresentative of the general public. Random sampling, however, selects participants purely by chance from a complete sampling frame of the population. This means individual differences (such as intelligence, social skills, and motivation) are likely to be distributed in the sample in the same way they are in the target population, leading to findings that can be more confidently generalized to all adults.

Max 3.83 marks total: - Up to 1.83 marks for explaining how volunteer sampling limits generalizability (volunteer bias): 1 mark: Volunteer bias (participants are self-selected, e.g., more motivated, higher empathy). 0.83 marks: Contextualizes to theory of mind/eyes test performance (e.g., they might perform better than average). - Up to 2 marks for comparing it to random sampling: 1 mark: Random sampling gives everyone an equal chance of being selected, reducing bias. 1 mark: Leads to a sample that reflects the true distribution of characteristics in the wider population, enhancing generalizability.

In Pozzulo et al.'s study, participants watched a video of a crime/event and then viewed either a target-present or target-absent line-up. 1. Why chosen: If a repeated measures design were used, participants would have to view multiple line-ups or be tested multiple times on the same crime. This would lead to severe order effects (e.g., practicing face-matching, becoming fatigued) and demand characteristics (realizing who the target is or figuring out that the target is absent in one of the line-ups). By using independent measures, each participant only makes one line-up decision, keeping their response natural and unbiased. 2. Drawback: The main drawback is the risk of participant variables (individual differences). Some children or adults may naturally have much better facial recognition skills or visual memory than others. Because different participants are in different groups, these individual differences could act as confounding variables, making it harder to establish a clear cause-and-effect relationship between the independent variable (target presence/absence) and the dependent variable (identification accuracy).

Max 3.83 marks total: - Up to 1.91 marks for explaining why independent measures was chosen: 1 mark: To prevent demand characteristics, order effects, or practice effects. 0.91 marks: Contextualizes to the line-up task (e.g., identifying the same target twice makes the task obvious/invalid). - Up to 1.92 marks for explaining the drawback of this design: 1 mark: Participant variables / individual differences are not controlled. 0.92 marks: Contextualizes to the study (e.g., differences in memory/eyewitness ability between the groups could confound results).

1. Ethical issue: The key ethical issue with using fMRI is protection from harm (both psychological and physical). The fMRI scanner is a highly confined, noisy space, which can cause severe claustrophobia and distress for some participants. In contrast, a self-report questionnaire carries minimal risk of physical or psychological distress. Furthermore, if the researcher accidentally detects an unexpected brain abnormality during the scan, this raises complex ethical issues regarding whether and how to inform the participant. 2. Practical issue: The practical issue is resource constraints (cost, equipment, and expertise). fMRI scans are extremely expensive to perform, requiring specialized medical machinery and highly trained neuroimaging experts to analyze the data. This makes it difficult to recruit large sample sizes, limiting the statistical power of the study. A self-report questionnaire, by contrast, is highly cost-effective, easy to distribute to hundreds of participants simultaneously, and requires no specialized equipment.

Max 3.83 marks total: - Up to 1.91 marks for the ethical issue: 1 mark: Identifies a valid ethical issue (e.g., protection from psychological harm/claustrophobia, or incidental findings). 0.91 marks: Compares it directly to self-report (which doesn't have these risks) or contextualizes it to the fMRI process. - Up to 1.92 marks for the practical issue: 1 mark: Identifies a valid practical issue (e.g., high cost, requirement of specialized technicians, small sample size due to scan duration). 0.92 marks: Contextualizes it to the comparison with self-report questionnaires (which are cheap and quick).

Strength: Participant variables are controlled because the exact same individuals participate in all conditions. This eliminates individual differences in concentration ability as a confounding variable. Weakness: Order effects are likely to occur. Participants might experience fatigue and perform worse in the second condition, or experience practice effects and perform better.

1 mark: Identifying a strength (e.g., control of participant variables). 1 mark: Applying the strength to the concentration/noise study. 1 mark: Identifying a weakness (e.g., order effects/boredom/fatigue). 1 mark: Applying the weakness to the concentration/noise study.

Ethical issue: Covert observations violate the principle of informed consent and potentially privacy, as individuals do not know they are in a study. Address: To address this, the researcher must keep all observations strictly anonymous, ensuring no names, photographs, or identifiable features are recorded, and conduct the observation only in public areas of the mall where privacy is not expected.

1 mark: Identifying the ethical issue (consent, privacy, or deception). 1 mark: Applying the issue directly to the shopping mall/recycling context. 1 mark: Proposing an appropriate solution (anonymity, debriefing, or public observation). 1 mark: Explaining how this solution effectively addresses the issue in this study.

Quantitative advantage: Numerical ratings of stress allow the researcher to compute averages, perform statistical tests, and easily compare stress levels before and after the mindfulness program. Qualitative advantage: Textual descriptions of feelings provide deep, descriptive depth, allowing the researcher to understand the subjective, personal experience of mindfulness that numeric scales cannot capture.

1 mark: Explaining an advantage of quantitative data (e.g., objectivity, easy comparison). 1 mark: Applying this advantage to the stress rating scale (1-10). 1 mark: Explaining an advantage of qualitative data (e.g., detail, understanding meaning). 1 mark: Applying this advantage to descriptions of mindfulness feelings.

Unstructured interviews are superior for sensitive topics like childhood phobias because they provide the flexibility to explore unique personal histories through open-ended, non-standardised follow-up questions. This helps build trust and rapport, encouraging participants to share deep personal experiences, which would be restricted by the rigid and predetermined questions of a structured interview.

1 mark: Identifying a key feature/strength of unstructured interviews (e.g., flexibility, follow-up questions). 1 mark: Explaining why a structured interview would be limited (e.g., rigid, lacks depth). 1-2 marks: Directly applying these concepts to the sensitive nature of childhood phobias (e.g., building trust, exploring individual clinical details of fears).

### Model Design for the Field Experiment

**1. Independent Variable (IV) and Dependent Variable (DV)**
* **IV:** The gender of the approaching stranger (Confederate A: Male vs. Confederate B: Female). Both confederates will be of similar age (approx. 22 years old), height (approx. 1.75m), and dressed identically in neutral attire (plain white t-shirt and blue jeans) to control for extraneous variables.
* **DV:** The comfortable interpersonal distance, operationally defined as the physical distance (in centimetres) between the participant and the confederate when the participant first shows a 'discomfort response' (e.g., leaning away, taking a step back, or speaking to stop the approach).

**2. Sample and Sampling Method**
* **Sample:** A total sample of 60 participants (30 males, 30 females, aged 18–65) who are sitting alone on public benches in a busy municipal park.
* **Sampling Technique:** Opportunity sampling. Researchers will target individuals who are sitting alone on pre-selected, isolated benches and who are not engaged in an active task like a phone call or reading.

**3. Procedure and Standardisation**
* The study will take place in a public park during daylight hours (12:00 PM to 4:00 PM) to control for natural lighting and visibility.
* A confederate (either male or female, randomised per trial) will start from a fixed starting point exactly 5 metres away from the seated participant.
* The confederate will walk at a constant, slow pace (approx. 1 step per second) directly toward the participant, maintaining a neutral facial expression and direct eye contact.
* A second researcher, disguised as a park visitor reading a book on an adjacent bench, will record the encounter on a high-definition video camera hidden inside a bag.
* The distance will be measured by counting the concrete pavement slabs (each pre-measured at exactly 50cm wide) between the participant's bench and the point where the participant reacts (e.g., shifts body position, moves their legs, or says 'excuse me'). The video will be analysed later by two independent coders to ensure inter-rater reliability of the distance measurements.

**4. Ethical Guidelines**
* **Deception and Informed Consent:** Because this is a field experiment, participants cannot give prior consent without ruining the ecological validity. To address this, a full retrospective debrief will occur immediately after the trial. A researcher will approach the participant, explain the true nature of the study, and ask for written consent to use their video and distance data. If they decline, the data and video recording will be permanently deleted.
* **Protection from Harm:** The confederate will immediately stop their approach and walk away if the participant displays any signs of high distress or verbal hostility, ensuring no psychological harm occurs. The experiment will be conducted in an open, safe environment to prevent participants from feeling physically trapped.

### Marking Scheme (Max 10 marks)

**Level 3 (8–10 marks):**
* The design is highly detailed, appropriate, and fully replicable.
* All four required elements (IV/DV, sample, standardisation, ethics) are addressed in detail with explicit application to the scenario.
* The candidate demonstrates an excellent understanding of experimental methodology, using accurate psychological terminology throughout.

**Level 2 (5–7 marks):**
* The design is mostly appropriate and describes a workable field experiment.
* Most of the required elements are addressed, but some details may be lacking (e.g., standardisation is vague, or the measurement of the DV is not fully operationalised).
* There is good application to the scenario, though some parts may be repetitive or lack clarity.

**Level 1 (1–4 marks):**
* The design is basic, has major omissions, or uses an inappropriate method (e.g., a laboratory experiment instead of a field experiment).
* Few of the required elements are addressed, or they are presented as a list of definitions without application to the personal space scenario.

**Level 0 (0 marks):**
* No creditable response or completely irrelevant design.

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### Key points to look for in responses:
* **IV/DV (2 marks):** Clear operationalisation of the stranger's gender (IV) and how distance is measured (DV) in centimetres or concrete tiles.
* **Sample/Sampling (2 marks):** Clear description of who the participants are, where they are found, and the use of opportunity sampling.
* **Standardisation (3 marks):** Strict controls described (e.g., confederate's dress, speed of walking, neutral expression, starting distance of 5m, control of time of day).
* **Ethics (3 marks):** Clear recognition of the ethical challenges of field experiments (lack of prior consent, potential distress) and how they are resolved (immediate retrospective debrief, option to delete video, stopping the trial if distress is observed).

1 mark for identifying the validity problem (e.g., feeding time naturally increases state aggression/competition, meaning the behavior observed is biased and not representative of their everyday level of aggression).
1 mark for suggesting an appropriate improvement (e.g., observing the dogs at multiple random intervals throughout the day or for a longer continuous period outside of feeding times).

Score 1 mark for identifying a valid problem with the ecological/construct validity of the observation timing.
Score 1 mark for a realistic and appropriate methodological improvement linked directly to the scenario.

1 mark for identifying the problem (order effects, e.g., participants might perform better on the second test because of practice/familiarity, or worse due to fatigue).
1 mark for explaining how to overcome it (counterbalancing, where half of the participants complete the condition in the reverse order).

Score 1 mark for identifying a valid problem (order/practice/fatigue effects) linked to the design.
Score 1 mark for suggesting an appropriate solution (counterbalancing or switching to an independent measures design).