2024 Cambridge IAS-Level Psychology (9990) 模擬試題連答案詳解

1 mark for identifying a strength (e.g., high ecological validity, low demand characteristics). 1 mark for explaining why this occurs in a natural experiment (e.g., because the researcher does not manipulate the IV, or because the behaviour occurs in a real-life setting).

1 mark for identifying a strength. 1 mark for explaining why it applies to a natural experiment.

Acceptable criteria include: mentally and physically healthy; no psychiatric disorders or psychoactive medication; no contraindications to MRI scans (e.g., no metal implants); mindfulness-naive (no yoga or meditation classes in the last 5 years, and fewer than 10 in lifetime); right-handed.

1 mark per correct criterion listed, up to a maximum of 2 marks.

The video sessions were recorded and a primary observer coded all monkey toy interactions. To assess reliability, a second observer independently coded a subset of the trials (approx 10% or 12 trials) and their scores were compared to calculate inter-rater reliability.

1 mark for stating that a second observer coded a subset of videos (e.g., 10% or 12 trials). 1 mark for stating that inter-rater reliability (or Cohen's Kappa) was calculated to check for agreement.

The child was shown highly attractive toys and allowed to play for a brief period (approx 2 minutes). The experimenter then interrupted and told the child that those toys were reserved for other children, which aroused mild frustration/aggression before they went to the next room.

1 mark for describing the child playing with attractive toys. 1 mark for describing the experimenter stopping the play and saying the toys were reserved for others.

The positive reinforcement therapy involved the boy being rewarded/praised by his mother for showing less fear or for handling buttons. This was done in vivo, with sessions lasting 20-30 minutes, where he gradually worked through his hierarchy of button distress.

1 mark for mentioning the use of praise/rewards from his mother. 1 mark for stating that it was combined with gradual exposure/handling buttons of increasing difficulty from the hierarchy.

One ethical strength is the extensive debriefing Milgram provided, where participants met the learner and were assured they were normal. One ethical weakness is the high level of psychological harm and distress caused, along with the restriction on the right to withdraw due to the researcher's standardized prods.

1 mark for a clearly outlined ethical strength with study context. 1 mark for a clearly outlined ethical weakness with study context.

The secondary reinforcer was the sound of a whistle. It became effective because it was repeatedly paired with the delivery of a primary reinforcer (food rewards like bananas), acting as a bridge so the elephant knew a correct action was being rewarded.

1 mark for identifying the secondary reinforcer as a whistle blow. 1 mark for explaining that it was paired with a primary reinforcer (food/treats) to establish the association.

Standardised procedures refer to a set of identical steps, instructions, and environmental factors applied to all participants in a study. They are important because they control potential extraneous variables and ensure that the procedure is reliable, meaning it can be replicated easily by other researchers.

1 mark for defining standardised procedures (e.g., identical instructions/steps for all participants). 1 mark for explaining their importance (e.g., increases reliability, allows replication, controls situational variables).

The prods served to compel the participant to go on with the shocks despite their personal moral objections (1 mark), and to maintain experimental standardization so that the experimenter's interaction with hesitant participants was consistent across all trials (1 mark).

1 mark per outline of a correct reason. Reason 1: To pressure/encourage/prompt the participant to continue giving shocks when they hesitated or wanted to stop. Reason 2: To ensure standardization/consistency of the procedure so that all participants experienced the same pressure from the experimenter.

The boy used the Feelings Thermometer (rated 0 to 8) to quantify his distress levels for various buttons (1 mark). This allowed the researchers to establish a clear hierarchy of fear/disgust to guide the exposure therapy and track improvements over time (1 mark).

1 mark for describing the scale itself (e.g., 9-point scale / ranging from 0 to 8 / where higher numbers meant more distress). 1 mark for describing its application (e.g., to create a hierarchy of fear/disgust / to measure the boy's feelings/distress before, during, or after therapy).

A plush toy was defined as a toy made of soft fabric/plush material, typically designed to be held or cuddled rather than rolled (1 mark). Examples of plush toys used include Winnie the Pooh, Raggedy Andy, Scooby Doo, a picture book, or a chamomile doll (1 mark).

1 mark for the definition of a plush toy (e.g., soft / cuddly / plush material / counterposed to wheeled toys). 1 mark for a correct example from the study (e.g., Winnie the Pooh, Raggedy Andy, Scooby Doo, picture book, chamomile doll).

In the study by Hassett et al., toys were categorized into: 1. Wheeled toys: Defined as toys with functional wheels or mechanical elements associated with movement. Examples include a dump truck, a police car, a wagon, and a fire truck. 2. Plush toys: Defined as soft, fabric-based toys representing animals or characters. Examples include a Winnie the Pooh soft toy, a Raggedy Andy doll, a teddy bear, and a plush dog.

Award 1 mark per correct detail of categorization/definition/examples up to a maximum of 4.2 marks. - 1 mark for identifying the two categories (wheeled and plush). - 1 mark for defining wheeled toys (mechanical/locomotive/wheels). - 1 mark for defining plush toys (soft/furry/animal-shaped). - 1 mark for giving correct examples from each category (e.g., truck for wheeled, teddy bear for plush).

The MBSR program used in Hölzel et al.'s study consisted of: 1. Duration: An 8-week intervention program. 2. Group sessions: Weekly meetings lasting 2.5 hours each. 3. Retreat: A full-day silent retreat lasting 6 hours, which took place during the 6th week of the course. 4. Home practice: Daily homework of 45 minutes using guided audio recordings, focusing on practices such as the body scan, mindful yoga, and sitting meditation.

Award 1 mark per correct descriptive detail of the MBSR program, up to a maximum of 4.2 marks. - 1 mark for stating it was an 8-week program. - 1 mark for identifying weekly meetings of 2.5 hours. - 1 mark for mentioning the full-day retreat (6 hours). - 1 mark for describing the 45-minute daily home practice (accept body scan, mindful yoga, sitting meditation, or audio guides).

Before the experiment began, Bandura et al. assessed the children's pre-existing aggression levels to match them: 1. Raters: Rated by the experimenter and their nursery teacher. 2. Rating scales: Assessed on four 5-point rating scales measuring physical aggression, verbal aggression, aggression toward inanimate objects, and aggressive inhibition (anxiety). 3. Reliability: The ratings showed very high inter-rater reliability (correlation of 0.89). 4. Matching: Children were arranged in triplets of similar scores and then randomly assigned to groups (matched pairs design).

Award 1 mark per correct detail of the pre-rating process, up to a maximum of 4.2 marks. - 1 mark for identifying the raters (experimenter and teacher). - 1 mark for specifying the rating scale format (four 5-point scales). - 1 mark for listing the behaviors rated (physical, verbal, inanimate aggression, inhibition). - 1 mark for explaining that children were matched in triplets/groups of similar scores to balance the groups.

The revised Eyes Test addressed limitations of the original version: 1. Items: Increased from 25 to 36 pairs of eyes. 2. Response options: Increased from 2 choices to 4 choices (one target and three foils). 3. Mental states: Removed simple/basic emotions (like happy, sad) and replaced them with complex cognitive states (e.g., contemplative). 4. Foil words: Foil options were chosen to have similar emotional valence to the target word. 5. Gender balance: Ensured equal numbers of male and female eyes (18 of each). 6. Glossary: Provided a glossary of terms with definitions to prevent vocabulary difficulties.

Award 1 mark per correct descriptive detail of a revision, up to a maximum of 4.2 marks. - 1 mark for 25 to 36 items. - 1 mark for 2 to 4 choice options. - 1 mark for changing simple to complex mental states. - 1 mark for introducing a glossary. - 1 mark for equalizing male/female eyes (18 of each). - 1 mark for improving foil quality (similar valence).

If the participant objected to delivering shocks, the experimenter used a sequence of four standardized verbal prods: 1. Prod 1: 'Please continue' or 'Please go on.' 2. Prod 2: 'The experiment requires that you continue.' 3. Prod 3: 'It is absolutely essential that you continue.' 4. Prod 4: 'You have no other choice, you must go on.' These were delivered in order. A special prod was used if the participant asked about physical injury: 'Although the shocks may be painful, there is no permanent tissue damage, so please go on.'

Award 1 mark per correct detail, up to a maximum of 4.2 marks. - 1 mark for stating that there were four standard prods delivered in a fixed order. - 1 mark for listing/describing Prod 1 or Prod 2 accurately. - 1 mark for listing/describing Prod 3 or Prod 4 accurately. - 1 mark for explaining that prods would reset if the participant complied and then resisted again, or for mentioning the specific 'no permanent tissue damage' prod.

Strength 1 (Quantitative data - Required): The study systematically collected quantitative data by tallying specific aggressive behaviours (such as physical imitative, verbal imitative, and non-imitative aggression) in 5-second intervals over a 20-minute period. This numeric data allows for direct, objective statistical comparisons between the groups (e.g., comparing the aggression levels of boys versus girls, or those exposed to aggressive versus non-aggressive models) without the risk of subjective qualitative interpretation.

Strength 2 (Standardisation and Controls): The research was conducted in highly controlled laboratory environments with standardised procedures. For example, every child in the aggressive condition witnessed the model perform the exact same pre-scripted sequence of physical attacks (e.g., hitting the Bobo doll with a mallet, tossing it in the air) and verbal statements (e.g., "Sock him in the nose"). This high level of control ensures reliability and allows the researchers to replicate the procedure easily to check for consistency.

Weakness 1 (Ecological Validity and Mundane Realism): The experimental design lacked mundane realism. Witnessing an adult model behave aggressively towards an inflatable plastic doll, and then being placed alone in a room with that same doll to have their play monitored, does not represent how children experience or learn aggression in natural social settings (such as a school playground or home environment). Therefore, the findings may not generalise well to real-world interpersonal aggression.

Weakness 2 (Ethical Issues): The study presents significant ethical concerns regarding the protection of participants from psychological harm. The children were deliberately subjected to a 'mild aggression arousal' phase where attractive toys were taken away to induce frustration. Furthermore, the children in the aggressive conditions were exposed to violent behaviour which they subsequently imitated, potentially leading to lasting aggressive habits, with no record of any deconditioning or debriefing process taking place after the trials.

Level 4 (8-9 marks):
- Two strengths (including quantitative data) and two weaknesses are clearly identified.
- Detailed explanation of each evaluation point is provided.
- All points are fully contextualised with accurate, specific references to the Bandura et al. study.

Level 3 (6-7 marks):
- Two strengths and two weaknesses are identified, but one may be lacking in detail or not fully explained.
- Contextualisation is present for most points, but may be slightly superficial.
- Or, only three points (e.g., two strengths and one weakness) are fully developed with excellent context.

Level 2 (4-5 marks):
- Evaluative points are identified, but the response may be imbalanced (e.g., only strengths, or only one strength and one weakness).
- Explanation of points is basic and lacks depth.
- Limited context from the Bandura et al. study is applied.

Level 1 (1-3 marks):
- Minimal evaluation is attempted.
- Points are generic (can apply to any study) with little to no context from Bandura et al.
- Shows basic psychological knowledge but lacks coherent evaluative structure.

Level 0 (0 marks):
- No response worthy of credit.

Strength 1 (Use of standardisation/objective measures): The researchers used a highly standardised observation protocol to measure toy preferences. Two independent observers coded video recordings of the monkey interactions using precise operational definitions for behaviours such as 'contact' (e.g., sitting with, holding, carrying, or manipulating a toy). The high inter-rater reliability (a Cohen's kappa coefficient of 0.90 for toy first held) demonstrates that the measurements were highly objective, consistent, and free from researcher bias.

Strength 2 (Controls for confounding variables): High controls were maintained within the outdoor enclosure. The masculine (wheeled) and feminine (plush) toys were placed in counterbalanced positions to control for any spatial preference bias that the monkeys might have had in the testing area. This ensured that the monkeys' choices were based on the properties of the toys themselves rather than their placement.

Weakness 1 (Generalisability - Required): A significant weakness of this study is its generalisability to humans. Although rhesus monkeys share evolutionary biological traits with humans, they lack the complex socialisation, cultural expectations, and cognitive structures that influence gender-role development in human children. Therefore, the finding that male monkeys prefer wheeled toys and female monkeys are more flexible with plush toys cannot be directly and simplistically generalised to explain human gendered toy preferences.

Weakness 2 (Ecological validity of the stimuli): The use of manufactured, human-designed toys (such as a Tonka truck and a Winnie-the-Pooh plush toy) in an animal study lacks ecological validity. Rhesus monkeys do not naturally encounter wheeled or plush items in their wild habitats. The interactions recorded might reflect responses to novel shapes, textures, or colours rather than a true biological disposition toward 'masculine' or 'feminine' play objects as understood in human psychology.

Level 4 (8-9 marks):
- Two strengths and two weaknesses are clearly identified, with at least one focused on generalisability.
- Every point is fully explained and highly contextualised using specific details from the Hassett et al. study (e.g., toy types, monkey sample details, specific behaviours coded).
- The writing is coherent, structured, and uses appropriate psychological terminology.

Level 3 (6-7 marks):
- Strengths and weaknesses are present, but the evaluation may be slightly uneven (e.g., three strong points and one weak point).
- Contextualisation is generally good but may lack precise details in one of the points.
- Demonstrates good understanding of the study and the evaluated concepts.

Level 2 (4-5 marks):
- Basic evaluation. May describe only two or three points well, or fail to address the required focus on generalisability.
- Limited context from the Hassett et al. study is present; points are somewhat generic and could apply to other animal/observational studies.

Level 1 (1-3 marks):
- Shows minimal grasp of evaluation.
- Points are brief, unsupported by examples, or largely descriptive of the study's procedure rather than evaluative.

Level 0 (0 marks):
- No response worthy of credit.

To operationalise an independent variable means to define exactly how it will be manipulated. In this scenario, noise can be defined quantitatively, such as setting a specific decibel level of white noise played via headphones for the experimental condition, and comparing this to a control condition of absolute silence. This makes the manipulation clear, objective, and reproducible.

1.76 marks total: [0.88 marks] For stating a specific, measurable manipulation of noise (e.g., defining a specific sound level like \(70\) dB of white noise). [0.88 marks] For describing a comparison condition (e.g., a silent control group) to show how the independent variable is manipulated across different levels.

A laboratory setting allows for a high degree of control over extraneous variables. In Andrade's study, this meant ensuring that all participants listened to the identical recorded telephone tape in the same dull room. This standardisation ensures that differences in memory recall were due to the doodling intervention rather than differences in how the message was delivered, thus increasing the internal validity and reliability.

1.76 marks total: [0.88 marks] For outlining a generic strength of laboratory experiments (such as standardisation or control over extraneous variables). [0.88 marks] For applying this strength directly to Andrade's study (e.g., mentioning the pre-recorded message of \(188\) words per minute or the standardised sheets).

A directional (one-tailed) hypothesis specifies the expected direction of the outcome (e.g., Group A will score higher than Group B). In contrast, a non-directional (two-tailed) hypothesis merely states that there will be a significant difference or correlation between the variables, without specifying which group will perform better or the direction of the correlation.

1.76 marks total: [0.88 marks] Clear definition of a directional (one-tailed) hypothesis. [0.88 marks] Clear definition of a non-directional (two-tailed) hypothesis that contrasts effectively with the directional one.

Milgram gathered qualitative observations of the participants' behavior, such as nervous laughing fits, sweating, stuttering, and groaning. This was extremely valuable because it demonstrated the intense psychological conflict the participants underwent between their desire to obey authority and their moral reluctance to harm another person, which could not be captured by the numerical voltage data alone.

1.76 marks total: [0.88 marks] For identifying a correct piece of qualitative data from Milgram's study (e.g., sweating, trembling, stuttering, groaning, or specific verbal quotes). [0.88 marks] For explaining why this qualitative data was useful (e.g., revealing internal psychological distress, showing the conflict between obedience and morality, adding depth/validity to quantitative findings).

A semi-structured interview combines fixed questions with the freedom to probe further. Its main strength is flexibility, allowing the researcher to gather richer, more detailed qualitative data that reflects the participant's true thoughts. Its main weakness is that because the questions diverge for different participants, it is harder to standardise the procedure, reducing reliability and making the data more difficult and time-consuming to compare and analyse.

1.76 marks total: [0.88 marks] Clear identification of one strength of semi-structured interviews (e.g., flexibility, ability to probe, richer detail). [0.88 marks] Clear identification of one weakness of semi-structured interviews (e.g., reduced reliability, harder to replicate, more difficult to analyse/compare).

In observational studies, subjectivity can threaten reliability. By having two observers independently rate the same children's aggressive behaviors (such as physical and verbal aggression), Bandura et al. could check for agreement. High correlation between their ratings (which was around \(r = 0.89\) or higher in the study) indicates that the coding system was reliable and that the observations were objective rather than influenced by personal observer bias.

1.76 marks total: [0.88 marks] Explaining the mechanism of inter-rater reliability (comparing/correlating independent observations for agreement). [0.88 marks] Applying this specifically to the context of Bandura's study (e.g., ensuring aggression scores were objective and not biased by a single observer's interpretation).

An opportunity sample consists of participants who are readily available and willing to take part at the time of the study. In a university context, this involves approaching students in a common area like a library or cafeteria. The major disadvantage is that it lacks representativeness; the sample is biased towards students who happen to be in that specific location at that specific time, meaning the findings cannot easily be generalised to the broader student population.

1.76 marks total: [0.88 marks] Correctly describing how to obtain an opportunity sample in the specified scenario (e.g., approaching available students in a central location like the library or canteen). [0.88 marks] Identifying a valid disadvantage of opportunity sampling (e.g., bias, lack of representativeness, or lack of generalisability).

Demand characteristics occur when participants alter their behavior because they think they know what the researcher expects to find. Dement and Kleitman controlled for this by ensuring participants had no contact with the experimenter immediately upon waking (speaking only through an intercom) and were not told whether they had been awakened during REM or NREM sleep, or after \(5\) or \(15\) minutes. This 'blind' design prevented participants from trying to tailor their dream descriptions or duration estimates to fit the research hypotheses.

1.76 marks total: [0.88 marks] Identifying the relevant control in Dement and Kleitman's procedure (e.g., participants being blind to their sleep stage/duration condition, or minimal contact via intercom). [0.88 marks] Explaining how this specific control prevented demand characteristics (e.g., prevented participants from guessing the hypothesis and bias their dream reports or time estimations).

The researcher can operationalise 'concentration' by measuring a specific performance output. For example, they could count the number of correct responses on a mathematical test, or the number of errors made during a proofreading task. This provides numerical, objective data that represents concentration level.

1 mark for identifying a valid quantitative measure (e.g., number of errors, score on a test). 1 mark for contextualising it to a specific task that represents concentration (e.g., proofreading, mathematical puzzles).

Piliavin et al. conducted a field experiment on a New York subway train where participants were completely unaware that they were part of an investigation. Unlike a laboratory environment where participants are aware of being tested and may show demand characteristics by altering their behavior, the subway passengers behaved naturally because they did not suspect they were in an experiment.

1 mark for explaining that the covert nature of the field experiment meant participants did not know they were in a study. 1 mark for linking this to the absence of changed behaviour/guessing the aim.

Because the boy was a child (9 years old), obtaining informed consent was highly important. The researchers addressed this by explaining the procedure and obtaining written informed consent from both the boy's mother and the boy himself. This ensured that both the primary caregiver and the child participant agreed to the therapy.

1 mark for identifying a relevant ethical guideline (e.g., informed consent, protection from psychological harm). 1 mark for explaining how the researchers addressed it in this specific study.

Qualitative data in Dement and Kleitman's study was obtained by recording the participants' verbal reports of their dream content into a tape recorder. A strength of collecting this data is that it gives a detailed, depth-filled understanding of the subjective dream experience, allowing researchers to determine if the narrative matched the eye movement patterns.

1 mark for identifying a valid qualitative data point from the study (verbal description of dream content). 1 mark for outlining a strength of qualitative data (e.g., high detail, explanatory power, insight into subjective experiences).

An experiment would require the researcher to manipulate sleep, which could cause harm to participants (e.g., sleep deprivation) or be difficult to enforce. A correlational design is more appropriate as it allows the researcher to naturally measure the existing relationship between the two variables without intervention or ethical violations.

1 mark for explaining a limitation of experiments or benefit of correlation in this scenario (e.g., ethical issues with sleep deprivation). 1 mark for linking the explanation directly to the variables in this study (hours of sleep and cognitive performance).

During the observation stage, each child's behavior was observed through a one-way mirror for a total duration of 20 minutes. This 20-minute period was divided into 5-second intervals (using an automated signaling device). The observer recorded which of the pre-categorized aggressive behaviors occurred in each 5-second interval, resulting in 240 response units per child.

1 mark for noting the division of time (e.g., 20 minutes total, 5-second intervals). 1 mark for explaining how the recording took place during these intervals (marking predefined behaviors).

Hassett et al. controlled for participant variables by calculating the proportion (relative frequency) of total interactions with masculine or feminine toys for each monkey. This controlled for individual variations in overall activity levels, as some monkeys were naturally more active and played much more than others, which would have skewed absolute counts.

1 mark for identifying the control measure (e.g., relative frequencies/proportions of toy interactions). 1 mark for explaining how this controlled for individual differences (e.g., adjusting for highly active versus inactive monkeys).

A major problem with the ecological validity of the Eyes Test is that it relies on static, black-and-white images showing only the eye region. In real life, deciphering another person's emotional state involves dynamic (moving) facial expressions, vocal cues, body posture, and a natural interactive context, making the test's task highly artificial.

1 mark for explaining an artificial aspect of the test (e.g., static, black-and-white, eyes-only images). 1 mark for explaining how this differs from real-world emotion recognition (e.g., dynamic movement, full face, body language, context).

An independent groups design uses different participants in each condition. This introduces the risk of participant variables, which are individual differences (such as natural memory capacity or attention span) that might affect the dependent variable. In Andrade's study, if the doodlers naturally had superior memories compared to the control group, this would make it look like doodling helped memory when it was actually just individual differences.

1 mark for explaining the disadvantage (individual differences / participant variables can confound results). 0.76 marks for applying this specifically to Andrade's study (e.g., natural memory capacity differences between the doodling and control groups).

In Piliavin et al.'s study, observers recorded qualitative data in the form of verbal remarks made by passengers (particularly women) on the train. This data was useful because it helped explain the quantitative findings (e.g., why people took longer to help or did not help at all) by revealing their internal justification, discomfort, or cognitive appraisal of the situation.

1 mark for identifying the qualitative data (verbal comments/remarks made by passengers). 0.76 marks for explaining its utility (helps understand the reasons behind helping/non-helping behavior, provides cognitive/emotional context).

A one-way mirror allows researchers to perform a covert observation. Since the children are unaware of the observer, they will not show social desirability bias or reactivity. In Bandura's study, this ensured that the children's imitative or non-imitative aggression was a true reflection of what they wanted to do, rather than playing to an audience or trying to please an adult.

1 mark for identifying the methodological advantage (covert observation reduces demand characteristics, reactivity, or social desirability). 0.76 marks for linking to Bandura's study (ensures children's aggressive or non-aggressive behavior is genuine and natural).

In Hassett et al.'s study, the dependent variable 'toy preference' was measured quantitatively using two operationalised behaviors: the total duration of contact (how long they spent interacting, holding, or looking at a toy) and the frequency of contacts (how many times they initiated contact with the toy). These were recorded separately for both plush and wheeled toys.

1 mark for describing the operationalised measures (frequency of contacts and duration of contacts). 0.76 marks for context (linking these measures to the two categories of toys: plush and wheeled).

An experiment must have a manipulated independent variable (IV) and a measured dependent variable (DV) to establish cause-and-effect. In Hölzel et al., the IV was manipulated (one group completed the MBSR mindfulness course, while the other was a wait-list control group), and the DV (grey matter concentration change) was measured. In contrast, a correlational study would simply look at the relationship between mindfulness scores and grey matter without manipulating any conditions.

1 mark for explaining that there is a manipulated IV (MBSR vs control group) and a measured DV (changes in grey matter). 0.76 marks for explaining how this differs from a correlation (which does not manipulate variables and cannot establish direct cause-and-effect).

(a) Three suggested behavioral categories for 'cooperative play': 1. Sharing toys: A child actively hands a toy to another child or allows them to use a toy they are currently playing with. 2. Verbal negotiation: Children talking to each other to plan a game or assign roles (e.g., 'You be the doctor and I will be the patient'). 3. Joint construction: Two or more children actively working together on the same physical task, such as building a single tower out of blocks. (b) How to use time sampling: Dr. Aris would divide the 60-minute session into set time intervals, such as 1-minute intervals. At the end of every minute, he would observe the target children and record which of the cooperative play behaviors occurred. He would repeat this for all 60 intervals.

Part (a): 3 marks total. 1 mark for each clearly operationalised, distinct, and appropriate behavioral category related to 'cooperative play'. Reject vague categories like 'playing together' unless defined with an observable action. Part (b): 1.33 marks. 1.33 marks for an accurate explanation of time sampling applied to the scenario (must mention observing/recording only at or during specific time intervals, e.g., every minute, rather than continuously).

(a) Independent Variable (IV): The participant's personality type (introvert vs. extravert). Dependent Variable (DV): The preferred interpersonal distance from the virtual stranger (e.g., measured in pixels or virtual centimeters on the computer task). (b) Controlling for demand characteristics: The researcher could use a filler task or a cover story (deception) so that participants do not realize the study is measuring preferred personal space. For example, they could tell participants that the study is testing visual reaction time to virtual characters, or include distractor trials involving non-human shapes, so participants do not consciously adjust their personal space choices to fit perceived expectations.

Part (a): 2 marks total. 1 mark for identifying the IV: personality type (introvert vs. extravert). 1 mark for identifying the DV: preferred interpersonal distance / distance chosen on the computerized task. Part (b): 2.33 marks. 1 mark for a clear control method (e.g., cover story, filler tasks, single-blind design). 1.33 marks for explaining how this controls for demand characteristics / expectations in the context of this specific study.

(a) Situational variable in school assembly: One situational variable is the seating arrangement or physical location of the students in the assembly hall. For example, students sitting at the back of the hall may be more easily distracted by peers, or may find it harder to hear the boring speech clearly compared to students sitting at the front, which would affect their memory recall scores independently of whether they were doodling. (b) Standardisation to minimise this variable: The teacher could standardise the environment by seating all participants in the same specific row of the assembly hall (e.g., alternating doodling and non-doodling students in the middle rows) or by playing the speech through individual headphones at a fixed volume for every student, ensuring that everyone receives the exact same auditory input and level of ambient noise.

Part (a): 2 marks total. 1 mark for identifying a plausible situational variable in a school assembly (e.g., noise levels, seating position, temperature, peer distractions). 1 mark for explaining how this variable could affect the DV (memory recall/results). Part (b): 2.33 marks. 1 mark for suggesting a standardisation technique. 1.33 marks for explaining how it directly minimises or controls the specific situational variable identified in part (a).

The proposed study successfully outlines a laboratory experiment with an independent measures design.

Key elements explained in the solution:
1. **IV Operationalisation**: Distinctly operationalised as classical music (Mozart, 50 dB) versus white noise (50 dB).
2. **DV Operationalisation**: Measured via objective, quantitative means (a 15-question comprehension test score out of 15 based on a specific text).
3. **Extraneous Variable Control**: Controls the text difficulty by keeping the reading material completely identical across both conditions, ensuring validity.
4. **Sample & Sampling**: Uses opportunity sampling to recruit 40 undergraduate students from a university library, detailing how they are selected and allocated.

Total Marks: 10

Marks are awarded across three level bands based on completeness, replication potential, and appropriateness to the scenario:

**Level 3 (8–10 marks):**
- The description of the study is clear, detailed, and fully replicable.
- All four required elements (IV, DV, control, sample/sampling) are present and effectively operationalised in the context of the scenario.

**Level 2 (5–7 marks):**
- The description is generally clear but may lack some detail to make it fully replicable.
- Most of the required elements are present. Some elements may lack clear operationalisation (e.g., stating 'concentration' is measured but not explaining *how* the test is scored).

**Level 1 (1–4 marks):**
- The description is basic, disjointed, or lacks critical detail.
- Important elements (such as the IV or DV) may be missing, or the design is not a laboratory experiment as requested.
- The study would not be replicable from the details provided.

**0 marks:**
- No response worthy of credit.