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

To measure the direction of eye movements, the researchers attached electrodes to the skin near the margins of the eyes (two around the eyes to record vertical and horizontal movements). These electrodes were connected to an electroencephalograph (EEG) machine (or polygraph) to record the electrical potentials generated by eye movements.

1 mark for mentioning electrodes attached near/around the eyes. 1 mark for mentioning the recording device (EEG/EOG/polygraph). 0.5 marks for identifying that this detected horizontal or vertical potentials/activity.

Hassett et al. defined interaction as any active physical contact with the toy. This included behaviors such as touching, holding, carrying, dragging, chewing, or pushing the toy. Merely looking at the toy or being in close proximity to it without contact did not count as interaction.

1 mark for stating that it required active physical contact (rather than just looking/proximity). 1 mark for providing at least two specific examples of contact (e.g., touching, carrying, dragging, chewing). 0.5 marks for clarifying what was excluded (e.g., proximity/looking only).

The feelings thermometer was a customized self-report scale ranging from 0 to 8. A score of 0 represented the lowest level of distress (no distress), while a score of 8 represented the highest level of distress. It was used to rate the boy's fear/distress for various types of buttons (e.g., large plastic buttons, small metallic buttons) to construct a hierarchy of fear.

1 mark for identifying it as a 9-point scale / scale from 0 to 8. 1 mark for explaining what the numbers represented (e.g., 0 = no distress/fear, 8 = maximum distress/fear). 0.5 marks for stating how it was used (e.g., to rate different buttons / create a hierarchy of fear).

A target-present line-up contains the photograph of the actual person (the target/culprit) who committed the mock crime, along with several innocent foils. A target-absent line-up does not contain the target; instead, the target is replaced by a target-substitute foil, meaning all individuals in the line-up are innocent.

1 mark for explaining 'target-present' (contains the actual culprit/target + foils). 1 mark for explaining 'target-absent' (does not contain the actual culprit/target, replaced by a foil). 0.5 marks for stating the purpose of comparing these (e.g., to test correct identification vs. correct rejection).

The children were rated beforehand on their aggressiveness by a female experimenter and a nursery school teacher who knew them well. They used four 5-point rating scales measuring physical aggression, verbal aggression, aggression toward inanimate objects, and aggressive inhibition. Based on these composite scores, the children were arranged in triplets and randomly assigned to one of the experimental groups or the control group (matched-pairs design).

1 mark for mentioning they were rated on aggression by a teacher and/or experimenter beforehand. 1 mark for mentioning the use of rating scales (or specific aggressive behaviors assessed, e.g., physical, verbal). 0.5 marks for explaining that they were matched into groups/triplets based on these scores (matched-pairs design).

Andrade designed the doodling sheet with pre-drawn alternating rows of squares and circles (each shape was 1 cm diameter) and a wide margin for writing names. Participants were instructed to shade these shapes. By asking them to shade pre-drawn shapes rather than creating their own drawings, the cognitive demand of the task was kept low and standardized.

1 mark for mentioning the pre-drawn shapes (squares and circles) on the response sheet. 1 mark for stating that participants had to shade inside these shapes. 0.5 marks for explaining that this minimized the cognitive effort/creative thinking required.

Throughout the shock generator progression, the learner was instructed to give no vocal response until 300 volts. At 300 volts, the learner pounded heavily on the wall of the room where he was buckled into the chair. His answers no longer appeared on the panel. At 315 volts, he pounded on the wall again, and thereafter did not answer or make any further noise.

1 mark for describing the action at 300 volts (pounding on the wall / stopping answering). 1 mark for describing the action at 315 volts (pounding on the wall again). 0.5 marks for stating that after 315 volts, no further responses or sounds were heard (complete silence).

The trainers used positive reinforcement by rewarding correct responses. When an elephant performed a desired behavior in response to a verbal cue, the trainer immediately blew a whistle (secondary reinforcer/bridge) and offered a food reward (primary reinforcer, such as bananas, chopped sugarcane, or tamarind). Incorrect behaviors were ignored (extinction) rather than punished.

1 mark for identifying the primary reinforcers used (food rewards/bananas/sugarcane). 1 mark for identifying the secondary reinforcer / bridge (the whistle blow). 0.5 marks for stating that correct behaviors were rewarded while incorrect behaviors were ignored (not punished).

(a) Dr. Aris should provide participants with a sheet of paper (e.g., A4) that contains rows of shapes (such as alternating circles and squares) to shade in, along with a pencil. He must instruct them to shade the circles and squares while listening to the voicemail, clarifying that it does not matter how neatly or quickly they do it, as it is just to relieve boredom.

(b) Standardising the voicemail (e.g., using the same pre-recorded speaker, monotonous tone, speed, and list of names/places) ensures high reliability. It acts as an experimental control, ensuring that all participants experience the exact same auditory stimuli, so any difference in memory recall is due to the doodling condition rather than variations in the message itself.

Part (a) [2 marks]:
- 1 mark for describing the physical materials (e.g., paper with shapes like circles/squares, pencil/pen to shade them in).
- 1 mark for describing the procedural instructions given (e.g., told to shade shapes, told that neatness/speed does not matter / it is just to relieve boredom).

Part (b) [2 marks]:
- 1 mark for identifying a reason for standardisation (e.g., controls extraneous variables, increases reliability, ensures internal validity).
- 1 mark for context-specific application (e.g., ensuring all hear the same monotonous tone, speed, or names/places in the voicemail).

(a) Maya could record:
1. The latency/speed of help (the time in seconds taken for the first bystander to offer help after the victim collapses).
2. The total number of people who step forward to help the victim.

(b) Maya must consider the issue of psychological harm/distress. Bystanders in the public park are unaware that the collapse is staged. Witnessing a sudden medical emergency can cause genuine anxiety, panic, or guilt if they choose not to help. Furthermore, debriefing everyone in a large, open public park may be difficult, leaving some participants distressed.

Part (a) [2 marks]:
- 1 mark for each valid quantitative measure linked to helping behavior (max 2 marks).
- Examples include: speed/time taken to help, number of helpers, number of verbal comments (if quantified), proportion of male vs. female helpers.

Part (b) [2 marks]:
- 1 mark for identifying a relevant ethical guidelines issue (e.g., protection from psychological harm, deception, lack of informed consent, difficulty of debriefing).
- 1 mark for explaining/linking it specifically to the park scenario (e.g., bystanders seeing a sudden medical collapse and feeling anxious, or the difficulty of chasing down moving park-goers to debrief them).

(a) Mr. Vance can establish a fixed observation interval, such as every 5 seconds. During each interval, the observer records whether specific pre-defined behaviors (e.g., imitative physical actions with the kitchen toys or non-imitative play) occur, using a structured coding sheet with predetermined categories.

(b) A controlled observation allows Mr. Vance to keep the environment identical for all children (such as having the exact same layout of the play kitchen, the same toys, and no external distractions). This increases replication and reliability, making it easier to determine if the children's behavior is a direct reaction to the teacher's model rather than external playground factors.

Part (a) [2 marks]:
- 1 mark for defining time sampling in this context (e.g., observing and recording behavior at fixed, regular intervals, such as every 5 seconds).
- 1 mark for referencing the recording of predetermined behavioral categories (e.g., marking down tally marks for imitative or non-imitative play on a checklist).

Part (b) [2 marks]:
- 1 mark for identifying a general strength of controlled observations (e.g., control of extraneous variables, standardisation, high reliability/replicability).
- 1 mark for linking it to the scenario (e.g., ensuring all children see the same kitchen setup, eliminating noise/distractions of a busy playground that would interfere with seeing if they imitate the teacher).

### Model Answer Structure:

**Introduction**
Introduce the concept of ethics in psychological research (designed to protect participants from harm and maintain the integrity of the discipline). Both Milgram (1963) and Piliavin et al. (1969) are social psychology studies that investigate human behavior in challenging situations, and both generated significant ethical debates regarding participant welfare and research procedures.

**Deception**
* **Milgram**: Deception was heavily used. Participants were told the study was about 'memory and learning', the draw for roles (teacher/learner) was rigged, the shocks were fake, and the 'learner' (Mr. Wallace) was a confederate. This was an ethical weakness as it violated trust. However, it was a methodological strength because without this deception, demand characteristics would have ruined the validity of the study.
* **Piliavin et al.**: Deception was also key; the emergency was staged by a victim (actor) collapsing. Passengers believed they were witnessing a genuine medical or substance-related emergency. Like Milgram, this was necessary to study authentic, unprompted bystander behavior in a natural environment, but it involved deceiving hundreds of unsuspecting members of the public.

**Informed Consent**
* **Milgram**: Participants volunteered to take part in a study about learning, meaning they gave consent, but it was not *informed* consent because they did not know the true nature of the research (obedience to destructive commands).
* **Piliavin et al.**: No consent was obtained at all. Participants were ordinary subway riders on the 8th Avenue line who found themselves part of an experiment without their knowledge or permission. This is a severe ethical weakness as it compromises individual autonomy.

**Protection from Psychological Harm**
* **Milgram**: Many participants experienced extreme stress, tension, and anxiety during the procedure. Observed behaviors included sweating, trembling, stuttering, groaning, and biting their lips. Three participants had full-blown uncontrollable seizures. This was a clear violation of the guideline to protect participants from harm, although Milgram did follow up with a questionnaire a year later showing 84% were glad to have participated.
* **Piliavin et al.**: Participants may have suffered psychological distress from witnessing a person collapse and feeling anxiety, guilt, or conflict about whether to help. There was also a potential risk of physical harm if any passenger had reacted aggressively to the model or victim.

**Right to Withdraw**
* **Milgram**: Although participants were told they could keep the payment regardless of when they stopped, the verbal prods used by the experimenter (e.g., 'The experiment requires that you continue') made it extremely difficult for them to exercise their right to withdraw.
* **Piliavin et al.**: Participants could not easily withdraw from the physical situation as they were on a moving train for 7.5 minutes between stations, forcing them to remain in the presence of the emergency.

**Debriefing**
* **Milgram**: All participants were fully debriefed. They were reunited with the unharmed learner, assured their behavior was normal, and had the opportunity to discuss the study, representing an ethical strength.
* **Piliavin et al.**: No debriefing was possible due to the field setting and the large number of transit passengers constantly boarding and exiting. This left participants to go about their day potentially distressed, which is a major ethical weakness.

### Marking Grid (12 Marks Total):

* **Level 4 (10–12 marks):**
* Evaluation is comprehensive, detailed, and balanced, showing a thorough comparison of both Milgram and Piliavin et al.
* Arguments on both sides (ethical strengths/justifications vs. weaknesses/violations) are clearly articulated.
* Explicit, accurate examples from both studies are used effectively to support every evaluative point.
* The essay is structured logically with excellent use of psychological terminology.

* **Level 3 (7–9 marks):**
* Good evaluation showing some balance and comparison of both studies.
* Ethical issues are discussed with relevant examples, though one study may be discussed in slightly more detail than the other.
* Mostly structured logically with good use of terminology.

* **Level 2 (4–6 marks):**
* Limited evaluation. The essay may focus heavily on description of the procedures rather than critical evaluation of ethical issues.
* It may only focus on one study in depth, or only cover a single ethical issue (e.g., just deception).
* Some psychological terminology is used, but structure may be disjointed.

* **Level 1 (1–3 marks):**
* Very basic or superficial answer. Shows limited understanding of the ethical issues or the studies themselves.
* Answers may simply list ethical guidelines without applying them to the studies.
* Minimal or no use of psychological terminology.

* **0 marks:**
* No creditworthy response.

Candidates should evaluate Fagen et al. (elephant learning) using strengths and weaknesses, alongside the named issue of using animals in psychological research. Strengths: 1. High standardisation: The training sessions followed a strict, consistent protocol. Every elephant was trained using positive reinforcement (PRT) with secondary reinforcers (whistles) and specific verbal cues (e.g., 'foot'). This makes the procedure highly replicable and reliable. 2. Objective quantitative data: The study recorded precise quantitative measures, such as the percentage of correct behavioral responses to cues (e.g., passing tasks). This allowed the researchers to objectively track learning progress and compare the performance of different elephants without researcher bias. Weaknesses: 1. Small sample size: The study used only five female Asian elephants. This small, highly specific sample makes it difficult to generalise the findings to male elephants, wild elephants, or other elephant species (such as African elephants). 2. Low ecological validity: The elephants were trained in a highly artificial controlled environment where they were rewarded for performing specific behaviors (like presenting their feet) that are not natural foraging or survival behaviors in the wild. Named Issue (Animals in research): 1. Species and Strain: Asian elephants are an endangered species, so their use must be highly justified. However, they were already in captivity (at a zoo/sanctuary) and the training was designed to improve their welfare by facilitating veterinary care, justifying their participation. 2. Pain and distress: The researchers used positive reinforcement (food rewards) rather than negative reinforcement or punishment. When elephants did not want to participate, the sessions were simply ended without consequence, ensuring no distress or harm occurred. 3. Number: The researchers minimized the sample size to just five elephants, which adheres to the principle of reduction in animal research.

Level 4 (8-10 marks): Evaluation is comprehensive, containing detailed and well-explained strengths and weaknesses. The named issue of using animals in psychological research is integrated effectively and applied accurately to the study. The argument is balanced, logical, and uses appropriate psychological terminology throughout. Level 3 (5-7 marks): Evaluation is good, containing some well-explained points. Both strengths and weaknesses are present, though they may be unevenly balanced. The named issue of using animals in psychological research is discussed and applied to the study, though it may lack some depth or detail. Level 2 (3-4 marks): Evaluation is basic. The candidate identifies some strengths and/or weaknesses, but they are not fully developed or lack detail. The named issue may be omitted or only mentioned superficially. Level 1 (1-2 marks): The candidate provides a very limited response, perhaps only listing a few brief points without explanation, or writing a response that lacks relevance. Level 0 (0 marks): No response worthy of credit.

A covert observation occurs when the researcher observes participants' behavior without their knowledge or consent (1 mark). This is often done to increase the validity of the study by minimizing demand characteristics or social desirability bias, ensuring that behaviors are natural (1 mark).

1 mark for a basic definition (unaware of being watched / researcher is hidden).
1 mark for elaboration/purpose (e.g., to ensure natural behavior / reduce demand characteristics / increase ecological validity).

A directional (one-tailed) hypothesis is a prediction made by a researcher that specifies the expected direction of the effect or relationship between variables (1 mark). For example, stating that 'participants who drink coffee will recall more words than those who do not' rather than just predicting a general difference (1 mark).

1 mark for stating that it predicts the specific direction of the relationship/difference (e.g. one group will perform better/worse than another).
1 mark for an appropriate example or contrast with non-directional (e.g., used when previous research suggests a particular outcome).

Participant variables refer to the individual differences between participants (such as age, personality, intelligence, or prior experience) that could affect their performance on the dependent variable (1 mark). These are a type of extraneous variable that can confound results, particularly in an independent measures design (1 mark).

1 mark for definition (individual differences/characteristics of participants that may affect the DV).
1 mark for elaboration/example (e.g., age, gender, intelligence; or how they act as an extraneous variable in independent measures designs).

Ecological validity is the degree to which the findings of a study can be generalized to real-world, natural environments and situations (1 mark). It depends on how realistic both the setting (environment) and the task (mundane realism) are to everyday life (1 mark).

1 mark for defining generalizability to real-life settings/situations.
1 mark for elaboration (e.g., mentioning mundane realism, the artificiality of laboratory settings, or giving an example).

Inter-rater reliability refers to the consistency between two or more researchers (observers) when they are coding or scoring the same behavior (1 mark). It is achieved when observers produce highly similar or identical data records, often checked using a correlation coefficient (1 mark).

1 mark for stating it is the agreement/consistency between two or more observers/raters.
1 mark for explaining how it is assessed or why it is important (e.g., comparing their data, using a correlation, ensuring objectivity, or establishing a coding scheme).

Part (a)
Strength: Naturalistic observation provides high ecological validity. The children are in their natural school playground environment, meaning their aggressive or non-aggressive behaviors are authentic and representative of real life, unlike in an artificial lab.
Weakness: There is a lack of control over extraneous variables. Events such as teacher intervention, weather changes, or pre-existing playground conflicts cannot be controlled, making it difficult to establish a clear cause-and-effect relationship.

Part (b)
Physical aggression: This can be operationalized as 'any observable act of physical force directed at another person or object, such as hitting, kicking, pushing, or throwing playground equipment at someone.'
Verbal aggression: This can be operationalized as 'any vocal expression of hostility, including shouting threats, calling names, or mocking other children.'

Part (a): [4 marks total]
- Strength: 1 mark for identifying a valid strength (e.g., high ecological validity). 1 mark for applying it to the context of observing children's aggression.
- Weakness: 1 mark for identifying a valid weakness (e.g., lack of control / extraneous variables). 1 mark for applying it to the context of a playground study.

Part (b): [4 marks total]
- Physical aggression operationalization: 2 marks (1 mark for a basic definition, 2 marks for a clear, fully operationalized definition with specific observable examples).
- Verbal aggression operationalization: 2 marks (1 mark for a basic definition, 2 marks for a clear, fully operationalized definition with specific observable examples).

Part (a)
Strength: By using a repeated measures design, participant variables (such as natural memory capacity or listening ability) are controlled because the same individuals participate in both conditions. This increases internal validity.
Weakness: Order effects or demand characteristics can occur. Participants might guess the aim of the study during the second trial, changing their effort levels or behavior.

Part (b)
To control for order effects, the researcher can use counterbalancing. This involves splitting the sample into two groups: Group 1 does the doodling condition first followed by the non-doodling condition, while Group 2 does the non-doodling condition first followed by the doodling condition.

Part (c)
In Andrade's original study, the memory test was unexpected (a surprise test of monitoring). In a repeated measures design, by the time participants complete the second condition, they will already expect a memory test based on their experience in the first condition. This means they will actively try to memorize names and places, meaning the test no longer measures passive focus or monitoring.

Part (a): [4 marks total]
- Strength: 1 mark for identifying a strength of repeated measures. 1 mark for explaining it in the context of the doodling replication.
- Weakness: 1 mark for identifying a weakness of repeated measures. 1 mark for explaining it in the context of the doodling replication.

Part (b): [2 marks total]
- 1 mark for identifying counterbalancing as the control method.
- 1 mark for explaining how counterbalancing is applied (e.g., alternating the order of the conditions for half the participants).

Part (c): [2 marks total]
- 1 mark for identifying that the memory test is no longer a surprise / participants expect it.
- 1 mark for explaining how this reduces validity (e.g., it now measures active rehearsal/memorization rather than passive concentration/monitoring).

Part (a)
IV: The state of the victim (drunk or ill).
DV: The time taken for help to be offered / latency of helping behavior.

Part (b)
Ethical issue: Deception or lack of protection from psychological harm. Passengers are subjected to a realistic emergency without consent, which can cause anxiety or guilt if they do not help. To address this, the researchers could conduct a rapid group debriefing at the end of the bus route, revealing that the emergency was simulated and explaining the purpose of the study to alleviate any negative feelings.

Part (c)
Practical problem: A city bus is typically much smaller and more turbulent than a subway car, with frequent abrupt stops, turns, and passengers entering/exiting from different doors. This makes standardizing the collapse of the victim and maintaining clear visibility difficult. Overcome: The researchers can standardise the trial to only occur during a specific, straight, 5-minute non-stop stretch of the bus route, ensuring the victim collapses safely near grab handles and in clear view of the seated passengers.

Part (a): [2 marks total]
- 1 mark for identifying the correct IV (state of victim: drunk vs. ill).
- 1 mark for identifying the correct DV (speed/latency of helping).

Part (b): [3 marks total]
- 1 mark for identifying a valid ethical issue (e.g., lack of consent, deception, or psychological harm).
- 1 mark for explaining the issue in the context of the bus experiment.
- 1 mark for a feasible solution to address the ethical issue (e.g., a debriefing strategy).

Part (c): [3 marks total]
- 1 mark for identifying a valid practical problem specific to a bus (e.g., turbulence, frequent stops, passenger flow, smaller space).
- 1 mark for explaining how this impacts the study (e.g., affecting the standardization of the collapse or visibility).
- 1 mark for suggesting a logical and practical solution to overcome this problem.

Part (a)
The researcher would predefine a list of specific behaviors (e.g., touching the toy with the trunk, shaking the toy, retrieving a treat). Every time any of these behaviors is observed during the study, the researcher records it as a tally, regardless of when it occurs.

Part (b)
Advantage: It ensures that key, brief learning behaviors (such as the exact moment of successful food retrieval) are captured and not missed, whereas time sampling might miss these actions if they occur outside the designated observation intervals.
Disadvantage: If multiple elephants are interacting with the toy simultaneously, it can be extremely difficult for a single observer to keep track of and accurately record every single event, leading to reduced reliability of the data.

Part (c)
This observation would collect quantitative data. This is because the researcher is using a structured checklist to count and record the numerical frequency of specific behaviors, rather than describing the behaviors qualitatively in words.

Part (a): [2 marks total]
- 1 mark for describing the creation of a checklist of specific predefined behaviors.
- 1 mark for stating that every instance of these behaviors is recorded/tallied as it happens.

Part (b): [4 marks total]
- Advantage: 1 mark for identifying a benefit of event sampling (capturing brief/rare events). 1 mark for applying it to the elephant context.
- Disadvantage: 1 mark for identifying a drawback of event sampling (difficulty tracking multiple events). 1 mark for applying it to the elephant context.

Part (c): [2 marks total]
- 1 mark for stating 'quantitative data'.
- 1 mark for explaining that it involves counting the frequency of predefined behaviors/producing numerical data.

### Sample High-Level Answer (10/10):

**1. Independent and Dependent Variables:**
* **Independent Variable (IV):** The age group of the confederate approaching the participant, operating at two levels: a child confederate (10 years old) and an adult confederate (30 years old).
* **Dependent Variable (DV):** Preferred personal space distance, defined operationally as the distance in centimeters (cm) between the front of the participant's shoes and the front of the confederate's shoes when the participant commands them to "stop".

**2. Experimental Design and Participant Allocation:**
* An **independent measures design** will be used to prevent demand characteristics and order effects.
* A sample of 40 university students (aged 18–22) will be recruited via volunteer sampling.
* Participants will be randomly allocated to one of two groups of 20 using a random number generator. Group 1 will be tested using the child confederate, and Group 2 will be tested using the adult confederate.

**3. Measuring the DV Safely and Objectively:**
* **Setup:** The experiment takes place in a quiet, 8-meter-long room. A discrete measuring tape is secured flat along the floor, running from the participant's designated standing spot (0 cm mark) to the starting position of the confederate (600 cm mark).
* **Procedure:** The participant stands at the 0 cm mark. The confederate (either the child or the adult, both of the same gender to avoid confounding effects) starts at the 600 cm mark. Upon a cue, the confederate walks slowly and at a standardized steady pace (approx. 0.5 meters per second) directly toward the participant, maintaining a neutral facial expression.
* **Measurement:** The participant is instructed to say "stop" as soon as they begin to feel uncomfortable with the distance. Once they say "stop", the confederate immediately freezes. The researcher (standing out of direct line of sight) reads the physical distance directly from the floor tape at the exact point between the tips of their shoes.
* **Safety:** The confederate is instructed to halt immediately upon hearing "stop" and will never advance closer than 20 cm, even if the participant fails to say stop, ensuring absolute physical safety.

**4. Controls to Ensure Reliability and Validity:**
* **Confederate Behavior & Appearance:** Both the 10-year-old and 30-year-old confederates will be female, wear identical plain blue jeans and a white t-shirt, and maintain a neutral facial expression with neutral eye contact (looking at the participant's forehead) during the approach.
* **Standardized Instructions:** Before the trial, every participant receives the identical recorded audio instruction: "Please stand facing the far wall. A person will slowly walk towards you. Say the word 'stop' clearly as soon as you feel they have reached the boundary of your comfortable personal space."
* **Environmental Consistency:** The testing room temperature will be kept constant at 21 degrees Celsius, with identical overhead LED lighting, and no background noise.

### Marking Criteria (Out of 10 marks total):

#### Level 4 (9-10 marks)
* The design is highly appropriate, detailed, and replicable.
* All key aspects of the prompt are addressed comprehensively (IV, DV, experimental design and allocation, safe/objective measurement, and at least two strong controls).
* The candidate demonstrates an excellent, coherent grasp of experimental methodology.

#### Level 3 (7-8 marks)
* The design is mostly appropriate and detailed.
* Most parts of the prompt are addressed clearly, and the study is largely replicable.
* May lack minor details regarding either the objective measurement of the DV or the specific controls for reliability.

#### Level 2 (4-6 marks)
* The design is outlined but lacks sufficient detail or contains structural flaws (e.g., inadequate controls, vague measurement of distance).
* Only some parts of the prompt are addressed adequately.

#### Level 1 (1-3 marks)
* The candidate provides a very basic or inappropriate design.
* Important elements (like the IV/DV or the experimental design) are missing or misunderstood. The study is not replicable.

#### Level 0 (0 marks)
* No creditable response, or the response merely copies material from the Perry et al. core study without designing a new experiment.

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### Key Elements to Look For:
* **IV (1 mark):** Must be clear and have at least two levels (e.g., child confederate vs. adult confederate).
* **DV (1 mark):** Must be operationalized (e.g., distance measured in centimeters).
* **Experimental Design (2 marks):** Identification of design (Independent measures or Repeated measures) with a logical explanation of participant allocation / counterbalancing.
* **Measurement of DV (2 marks):** Clear description of how the distance is measured objectively (e.g., floor tape) and safely (e.g., stopping rules).
* **Controls (2 marks):** At least two standardized controls detailed (e.g., confederate clothing, speed of walk, room layout, standardized verbal instructions).
* **Coherence and Feasibility (2 marks):** Overall feasibility of the laboratory setup as a logical scientific test.

Part (a):
- Inter-rater reliability is crucial because 'aggressive play behaviour' is highly subjective and open to individual interpretation. Having two or more observers independently code the same children's behaviour and comparing their tallies ensures that the observations are consistent and objective, rather than reflecting individual observer bias.
- High inter-rater reliability (e.g., achieving a Cohen's kappa or correlation coefficient of 0.80 or above) confirms that the behavioural categories are being applied consistently across different participants.

Part (b):
- Problem: A naturalistic observation on a playground lacks standardization. The situations, peer interactions, and games being played will naturally vary from day to day, making the study difficult to replicate under identical conditions, which threatens its reliability.
- Solution: To overcome this, Dr Aris can standardize the observation procedure by using a highly structured time-sampling method (e.g., observing for exactly 5 minutes at the same time each day) and using a clearly defined behavioural checklist (with specific operationalised actions like pushing, hitting, or shouting) so that the measurement process is highly consistent.

Part (a): [2 marks]
- 1 mark: For explaining what inter-rater reliability is in the context of this study (e.g., consistency between different observers' ratings of aggressive play).
- 1 mark: For explaining why it is important (e.g., to reduce subjective interpretation/bias, ensuring objective and consistent data collection).

Part (b): [2 marks]
- 1 mark: For identifying a specific reliability issue related to naturalistic playground observations (e.g., lack of standardisation/control over situations, difficulty of replication due to changing external events).
- 1 mark: For suggesting a plausible solution to address this problem (e.g., using a standardised, highly detailed behavioural checklist, or time-sampling with fixed, pre-set intervals to standardise the observation periods).

Part (a):
- To assess the reliability of the actor's performance, Chloe can conduct a pilot study or training sessions and film the actor performing the grocery-drop multiple times.
- She can then have independent raters use a checklist to score the consistency of key behaviours (such as the loudness of the crash, the phrasing of any vocalisation, and the exact physical posture). If there is a high correlation (e.g., 0.80+) between the actor's actions across trials, the performance is reliable.

Part (b):
- Problem: The natural shopping mall environment is highly unpredictable. For example, the density of crowds or foot traffic near the actor will naturally fluctuate across different trials, meaning some trials will have many potential helpers while others have very few, reducing the consistency of the testing conditions.
- Solution: Chloe can overcome this by establishing a strict standard for when a trial can begin. She could specify that the actor only drops the groceries when there are between 5 and 10 shoppers walking within a designated 5-metre zone around them, thereby standardising the crowd density across trials.

Part (a): [2 marks]
- 1 mark: For identifying a method to assess reliability (e.g., recording/piloting the performance, using independent observers/raters, or standardising the script).
- 1 mark: For explaining how this applies specifically to the actor's behaviour in this study (e.g., checking if the physical drop, expressions, or verbal cues are identical across trials).

Part (b): [2 marks]
- 1 mark: For identifying a reliability problem caused by the natural environment (e.g., fluctuating crowd density, noise levels, or physical obstructions that affect replication).
- 1 mark: For proposing an appropriate methodological solution to standardise or control this variable (e.g., setting strict criteria for foot traffic volume before initiating a trial, or holding trials only at specific, comparable times of day).