2023 Cambridge IAS-Level Psychology (9990) 模擬試題連答案詳解

(a) Description of the mock telephone message:
- The message was recorded on a cassette tape by a member of the psychology department.
- It lasted approximately 2.5 minutes.
- It was played at a comfortable, audible volume.
- It was read at a monotonous pace of 110 words per minute.
- The content was a telephone conversation about a party, mentioning 8 names of people who were attending, 3 names of people who were not attending (and 1 cat), and 8 place names, along with irrelevant chatter.

(b) Reason for the monotonous pace:
- Recording the message at a monotonous pace was designed to make the task intentionally boring and unengaging.
- Under normal conditions, a person's attention might be naturally captured by changes in vocal tone or exciting content, which would reduce daydreaming.
- By ensuring the tape was extremely dry and monotonous, the researchers created a low-salience environment where daydreaming was highly likely to occur. This allowed them to test if doodling could help maintain attention and reduce daydreaming in a highly controlled, boring situation.

(a) [2.5 marks maximum]
- 1 mark for each descriptive point of the message, up to 2 marks. An additional 0.5 marks is awarded for exact details (e.g., 2.5 minutes, 110 words per minute, 8 names of attendees).
- Example: The message was 2.5 minutes long (0.5 marks) and read at a monotonous pace (1 mark). It contained the names of 8 people attending a party (1 mark).

(b) [3 marks maximum]
- 1 mark for identifying a basic reason (e.g., to make it boring).
- 2 marks for explaining how this links to the study's aim (e.g., to induce boredom/daydreaming so that doodling's effect could be tested).
- 3 marks for a fully developed explanation incorporating psychological context (e.g., controlling for auditory interest as a confounding variable; ensuring the tape lacked natural salience so that cognitive resources would lapse without a tool like doodling).

(a) Monitoring performance scoring:
- Monitoring performance was calculated as the number of correct names of party-goers identified by the participant minus the number of false alarms.
- False alarms included names of people who were mentioned as not attending (or the cat), or completely new names not present on the tape.
- Plausible misspellings (such as "Greg" instead of "Craig") were counted as correct.

(b) Instructions given only to the doodling condition:
- Participants were told to use a pencil to shade in the shapes (squares and circles) on the paper provided.
- They were told that it did not matter how neatly or quickly they shaded the shapes.
- They were explicitly told that the shading task was just to relieve boredom.

(a) [2.5 marks maximum]
- 1 mark for stating it was correct names minus false alarms.
- 1 mark for explaining what a "false alarm" was (naming non-attendees or random names).
- 0.5 marks for mentioning how misspellings were treated (accepted if close).

(b) [3 marks maximum]
- 1.5 marks for each distinct instruction correctly identified, up to 3 marks.
- Example: They were told to shade in the shapes on the sheet (1.5 marks); they were told that neatness or speed did not matter (1.5 marks).

(a) Distressing buttons and ratings:
- Small, clear plastic buttons (school shirt buttons), which received a distress rating of 8 (on the 9-point Distress Feelings Thermometer).
- Small, colored plastic buttons, which also received a distress rating of 8.

(b) Change in distress rating:
- During the imagery exposure therapy, the boy was asked to imagine buttons falling on him, which initially generated high levels of distress.
- As the session progressed and cognitive restructuring took place, the boy's self-reported distress ratings decreased significantly.
- For example, imagining large numbers of buttons falling all over his body decreased from a distress rating of 8 to 5, and eventually down to 3 by the end of the sessions, showing a substantial reduction in disgust and fear.

(a) [2.5 marks maximum]
- 1 mark for identifying small clear plastic buttons.
- 1 mark for identifying small colored plastic buttons.
- 0.5 marks for stating the correct distress rating of 8 for both/either.

(b) [3 marks maximum]
- 1 mark for a basic statement that distress decreased.
- 2 marks for describing how the change was achieved (via imagining/cognitive restructuring) or quoting a specific reduction.
- 3 marks for a detailed description that includes pre-and post-exposure ratings (e.g., falling buttons reducing from 8 to 5 to 3) showing clear progress over the course of the session.

(a) Initial classical conditioning event:
- When the boy was 5 years old, he was in an art class at school.
- He ran out of buttons for his project, so he went to the teacher's desk to get more from a large bowl.
- As he reached for them, his hand slipped and the bowl of buttons fell, spilling all over him.
- This event was highly embarrassing and frightening, pairing the neutral stimulus (buttons) with an unconditioned response of intense distress and embarrassment, establishing his phobia.

(b) Strength and weakness of using a case study:
- Strength: It provided rich, highly detailed qualitative data (such as the boy's thoughts, emotions, and specific distress ratings over time). This allowed researchers to understand the unique cognitive processes of button phobia and tailor the therapy to his exact experiences.
- Weakness: It has low generalisability. Because the study focused on a single 9-year-old Hispanic boy, the findings regarding button phobia and the effectiveness of imagery exposure might not apply to individuals of different ages, genders, cultures, or those experiencing different types of phobias.

(a) [2.5 marks maximum]
- 1 mark for stating he was in an art class and ran out of buttons / went to teacher's desk.
- 1 mark for describing the bowl of buttons falling on him.
- 0.5 marks for mentioning his age (5 years old) or the emotional reaction (distress/embarrassment).

(b) [3 marks maximum]
- 1.5 marks for a clearly explained strength, linked to the study.
- 1.5 marks for a clearly explained weakness, linked to the study.
- Note: If a strength or weakness is generic (not linked to Saavedra and Silverman), award a maximum of 1 mark for each.

(a) Matching the children:
- The children were rated on their baseline aggression before the experiment began by an experimenter who knew them and their nursery school teacher.
- They were rated on four 5-point scales measuring physical aggression, verbal aggression, aggression toward inanimate objects, and aggressive inhibition.
- The scores were summed, and children with similar overall aggression ratings were grouped into triplets (triads) and randomly assigned to one of the three experimental conditions.

(b) Importance of matching as a control:
- Since this study investigated whether children learn aggression by observing models, it was essential to control for pre-existing individual differences in aggression (participant variables).
- If one experimental group happened to have naturally highly aggressive children while another group had passive children, any difference in aggression observed after the model exposure could be attributed to natural personality traits rather than the model's behavior.
- Matching ensured that all groups had an equal distribution of baseline aggression, increasing the internal validity of the experiment by isolating the independent variable (model behavior) as the cause of any observed aggression.

(a) [2.5 marks maximum]
- 1 mark for stating they were rated on baseline aggression by a teacher and experimenter.
- 1 mark for explaining the four categories of aggression rated (or mentioning the 5-point scales).
- 0.5 marks for explaining that they were grouped into triads and randomly assigned to conditions.

(b) [3 marks maximum]
- 1 mark for identifying that it controls for participant variables / individual differences.
- 2 marks for explaining why this matters (e.g., avoiding pre-existing aggression from confounding results).
- 3 marks for a full explanation showing how it ensures internal validity by isolating the IV (exposure to model) rather than baseline aggression levels as the cause of the DV.

(a) Physical behaviors of the models:
- Aggressive behaviors: The model laid the Bobo doll on its side, sat on it, and punched it repeatedly on the nose. They also raised the Bobo doll, struck it on the head with a mallet, and tossed it into the air and kicked it around the room.
- Non-aggressive behaviors: The model completely ignored the Bobo doll and sat quietly in the corner, assembling a Tinker Toy set in a subdued manner.

(b) Measuring imitation of physical aggression:
- The children were observed through a one-way mirror in Room 3.
- An observer recorded the child's behavior using time sampling, where observations were made in 5-second intervals over a total period of 20 minutes (giving 240 response units per child).
- To count as "imitation of physical aggression", the child had to perform the exact physical acts of the model, such as sitting on the Bobo doll and punching it, hitting it with the mallet, or tossing and kicking it.

(a) [2.5 marks maximum]
- 1 mark for describing the aggressive acts (e.g., sitting on Bobo, punching, mallet hitting, tossing/kicking).
- 1 mark for describing the non-aggressive acts (e.g., ignoring Bobo, playing with Tinker Toys quietly).
- 0.5 marks if both are detailed and accurate.

(b) [3 marks maximum]
- 1 mark for stating that observations were conducted through a one-way mirror.
- 1 mark for mentioning the use of time sampling / 5-second intervals (or the 20-minute duration).
- 1 mark for defining the behavioral criteria (e.g., performing the exact physical acts as the model like mallet-striking or punching).

(a) Instructions regarding substances:
- Participants were instructed to avoid drinking alcohol and beverages containing caffeine (such as coffee, tea, or cola) on the day of the study.
- They were told to eat their normal meals during the day (meaning no dietary restrictions other than avoiding alcohol/caffeine).

(b) Necessity for validity:
- Alcohol and caffeine are physiological stimulants and depressants that alter central nervous system activity, which directly affects sleep architecture.
- For example, caffeine can delay sleep onset and reduce REM sleep, while alcohol can disrupt REM sleep cycles and alter EEG brainwave patterns.
- If participants consumed these substances, it would act as a major confounding variable. Any differences or patterns in dream recall or REM sleep might be due to the chemical effects of the drugs rather than the natural biological stages of sleep, thereby reducing the internal validity of the findings.

(a) [2.5 marks maximum]
- 1 mark for stating they had to avoid alcohol.
- 1 mark for stating they had to avoid caffeine / caffeinated drinks (or giving examples like coffee, tea, cola).
- 0.5 marks for stating they were told to eat normally.

(b) [3 marks maximum]
- 1 mark for stating that these substances affect sleep / EEG patterns.
- 2 marks for explaining how they act as confounding variables (e.g., altering REM sleep or dream recall).
- 3 marks for linking this directly to the internal validity of the study (e.g., ensuring that any sleep and dreaming patterns recorded were natural and not a result of substance consumption).

(a) Changes to the Eyes Test:
- Number of items: The number of pairs of eyes was increased from 25 to 36.
- Number of response options: The options per question were increased from 2 (forced choice between target and foil) to 4 (target and three foils).
- Glossary: A glossary of terms with definitions and example sentences was included for participants to use if they did not understand the meaning of any words.
- Opposite words removed: Target/foil words that were simple semantic opposites (e.g., happy/sad) were replaced with more complex, subtle mental states.
- Gender balance: The ratio of male and female eyes was balanced (18 male, 18 female pairs).

(b) How a change resolved a limitation:
- Change from 2 to 4 options: In the original test, a 2-option choice meant participants had a 50% chance of guessing the correct answer, leading to high chance scores and a ceiling effect (where many scored perfectly). Increasing the options to 4 reduced the probability of guessing correctly to 25%, making the test much more sensitive in detecting subtle individual differences in Theory of Mind.
- Addition of a glossary: In the original test, a low score could be due to a participant's poor vocabulary (not knowing what words like "apathetic" or "insincere" meant) rather than an inability to judge emotion. The glossary resolved this limitation by ensuring that language comprehension was not a confounding variable, thus increasing the validity of the test.

(a) [2.5 marks maximum]
- 1 mark for each change identified, up to 2 marks. An additional 0.5 marks is awarded for specifying precise details (such as the exact number of items changing from 25 to 36, or 2 to 4 options).
- Example: The number of options was increased from 2 to 4 (1.5 marks), and a glossary of terms was added (1 mark).

(b) [3 marks maximum]
- 1 mark for identifying the limitation of the original version (e.g., chance guessing or vocabulary issues).
- 2 marks for explaining how the specific change directly addressed this limitation.
- 3 marks for explaining the psychological significance of this resolution (e.g., reducing the ceiling effect to improve discrimination of scores, or control for language ability to improve internal validity of the Theory of Mind measure).

Part (a):
- The study used opportunity sampling.
- Participants were recruited from a participant panel at the Medical Research Council (MRC) Applied Psychology Unit.
- They had just completed an unrelated study and were asked if they would mind spending another 5 minutes helping with a new study as they were preparing to go home.

Part (b):
- A major strength of opportunity sampling is that it is highly convenient and saves time/resources.
- In Andrade's study, because the participants were already physically present at the MRC facility, the researcher did not have to spend time setting up advertisements, mailing out flyers, or waiting for people to travel to the lab.
- This allowed for a highly efficient recruitment process to obtain the sample of 40 participants.

Part (a):
- 1 mark for identifying opportunity sampling / noting they were from a participant panel.
- 1 mark for outlining the procedural context (e.g., they had just finished another unrelated study and were asked to stay for 5 minutes as they were leaving).

Part (b):
- 1 mark for identifying a valid strength of opportunity sampling (e.g., convenience, time-saving, cost-effective).
- 1 mark for linking the strength directly to Andrade's study (e.g., the participants were already at the MRC unit/lab).
- 1 mark for detailed explanation/contextualization of the benefit (e.g., meaning the researchers did not need to spend time or money advertising for volunteers, making the study much quicker to initiate).

To answer this 10-mark evaluation question successfully, students must structure their response to include: 1. Two distinct strengths of the study by Hassett et al., explicitly applied to the context and details of the study (e.g., standardisation, quantitative data, or objectivity). 2. Two distinct weaknesses of the study, also explicitly applied (e.g., low generalisability, sample bias/unequal participation rates, or ecological validity issues). 3. A dedicated discussion of the named debate: nature versus nurture, demonstrating how the study's findings and methodology support or challenge either side of the debate. 4. A balanced, cohesive, and well-structured essay format.

Marks are awarded using a level of response marking grid: Level 4 (8-10 marks): Evaluation is detailed, balanced (two strengths and two weaknesses), and shows excellent understanding of Hassett et al. The nature versus nurture debate is thoroughly discussed and explicitly linked to the study. Level 3 (5-7 marks): Evaluation is good, with some development of the strengths and weaknesses. The nature versus nurture debate is addressed, though it may lack depth or direct integration with the study's findings. Level 2 (3-4 marks): Evaluation is limited. The candidate may only focus on strengths or weaknesses, or provide brief, undeveloped points. The nature versus nurture debate may be omitted or only mentioned superficially. Level 1 (1-2 marks): The response is highly descriptive or contains very basic, generic evaluative points with little to no application to Hassett et al. Level 0 (0 marks): No response worthy of credit.

1. It ensures consistency in how aggression is defined and measured. Multiple observers rated the children's behaviors behind a one-way mirror, so they needed to agree on what actions constituted physical, verbal, or non-aggressive behaviors.
2. It reduces observer bias and subjective interpretation. Without high inter-rater reliability, one observer might rate an action as aggressive while another might not, making the collected data subjective and unreliable.
3. Achieving a high correlation (the study reported a correlation coefficient of approximately \(0.90\)) increases the internal validity of the study, meaning the researchers could confidently draw conclusions about the imitation of aggression.

1 mark for explaining what inter-rater reliability achieves (consistency or agreement between multiple observers).
1 mark for applying to the context of Bandura et al. (e.g., observers rating children's aggressive behaviors through a one-way mirror).
1 mark for explaining why this is important for the study (e.g., reduces observer bias, increases objectivity, ensures validity of conclusions, or citing the high correlation of \(0.90\)).

Advantage:
- Opportunity sampling is a very quick and convenient way to recruit participants who are readily available at the time of the research, saving time and resources compared to other methods like random or systematic sampling.

Disadvantage:
- The sample is highly likely to be unrepresentative or biased because the psychologist is only choosing participants who happen to be present in a specific location (such as a local clinic or school). This makes it difficult to generalise any successful outcomes of the button phobia treatment to the wider population of individuals with specific phobias.

1 mark for a clearly explained advantage (e.g., convenience, saving time, low cost).
1 mark for a clearly explained disadvantage (e.g., biased sample, lack of representativeness).
1 mark for explicit application to the context of Saavedra and Silverman's replication (e.g., referencing button phobics, clinical patients, or children with specific phobias).

Once the experiment was over, Milgram provided a comprehensive debriefing:
- He disclosed the use of deception, explaining to the participants that no actual electric shocks had been administered and that the 'learner' was an accomplice.
- He introduced the participants to the unharmed learner (Mr. Wallace) to reassure them that he was safe and well, aiming to alleviate any immediate psychological distress or guilt.
- He provided a post-experimental interview and later sent a follow-up questionnaire and psychiatric report to ensure that participants suffered no long-term psychological damage.

1 mark for explaining that the deception was revealed (e.g., participants were told the true aim and that no shocks were given).
1 mark for mentioning the friendly reconciliation or introduction to the unharmed learner (Mr. Wallace) to reduce distress.
1 mark for mentioning the long-term follow-up (e.g., sending a questionnaire or arranging a psychiatric assessment to ensure no lasting psychological harm).

Part (a):
An independent measures design means that the researcher uses entirely different participants for each level of the independent variable. In this context, one group of participants would be placed in the doodling condition, and a completely separate group of participants would be placed in the control (non-doodling) condition.

Part (b):
To control for individual differences (such as natural memory capacity or attention span), the researcher could use random allocation. This involves randomly assigning participants to either the doodling or control group (e.g., pulling names out of a hat or using a random number generator). This ensures that any individual differences in memory ability are distributed evenly across both conditions, preventing them from becoming confounding variables.

Part (a) [1 mark]:
- 1 mark for defining independent measures clearly within the context of the study (i.e., separate groups of participants for the doodling and non-doodling conditions).

Part (b) [2 marks]:
- 1 mark for identifying a valid method (e.g., random allocation, pre-screening/matching for baseline memory capability).
- 1 mark for explaining how this method controls for individual differences in this specific study (e.g., ensures that naturally high or low memory retention abilities are evenly distributed between the doodling and control groups, preventing bias).

Advantage:
- Collecting quantitative data (such as the score out of \(36\) on the Eyes Test) allows for objective statistical comparisons between the different groups (e.g., comparing the AS/HFA group to the general population). It makes it simple to determine if differences in theory of mind are statistically significant.

Disadvantage:
- Quantitative data lacks depth and descriptive detail. A simple score does not explain the cognitive processing or visual cues a participant used to decide on a specific emotion, nor does it capture whether they were confused by alternative complex terms, thus giving an incomplete picture of their social-cognitive understanding.

1 mark for a clearly explained advantage of quantitative data in this study (e.g., ease of comparison between groups, statistical analysis, high objectivity).
1 mark for a clearly explained disadvantage (e.g., lack of depth, reductionist nature, no understanding of 'why' or the thought process).
1 mark for contextual application to Baron-Cohen's study (e.g., referring to the Eyes Test scores out of \(36\), the different groups compared, or the selection of complex emotional terms).

1. This instruction controlled for confounding participant variables (physiological state). Caffeine (a stimulant) and alcohol (a depressant) actively alter normal sleep patterns, such as delaying the onset of REM sleep or reducing the overall amount of REM sleep.
2. If participants consumed these substances, their EEG readings and dream recall would be distorted by these chemical effects rather than reflecting their natural, baseline sleep cycles.
3. This control was vital for internal validity, ensuring that the researchers were genuinely measuring the relationship between physiological sleep stages (REM/NREM) and the psychological experience of dreaming, allowing them to establish a clear cause-and-effect relationship.

1 mark for identifying how caffeine/alcohol act as confounding physiological variables (e.g., altering sleep architecture, EEG readings, or dream recall).
1 mark for explaining that eliminating these substances ensures sleep patterns remain natural and baseline.
1 mark for linking this directly to internal validity (e.g., allowing researchers to confidently establish a cause-and-effect relationship between REM sleep and dreaming, free from chemical interference).

**(a) Identify the IV and DV [2 marks]**
- 1 mark for identifying the IV: The type of retail store/shop (small independent vs. large supermarket).
- 1 mark for identifying the DV: Helping behaviors (or frequency of helping).

**(b) Operationalize 'helping behavior' [2 marks]**
- 1 mark for each clear, objective, and observable behavioral category (up to 2 marks).
- Examples:
- Category 1: Holding the entrance/exit door open for someone carrying bags.
- Category 2: Picking up an item dropped by another customer and handing it back to them.

**(c) Inter-rater reliability [2 marks]**
- 1 mark for proposing a second observer working independently.
- 1 mark for comparing results and calculating a correlation coefficient (or looking for high percentage agreement).
- *Example:* Have a second observer watch the same shoppers at the same time and record tallies independently. They then correlate their tallies; if they have a correlation of +0.80 or higher, the observations are reliable.

**(d) Methodological weakness of naturalistic observation [2 marks]**
- 1 mark for identifying a weakness (e.g., lack of control over extraneous variables, observer bias, replication difficulties).
- 1 mark for linking this weakness directly to Dr. Aris's scenario.
- *Example:* There is a lack of control over extraneous variables (1 mark). For instance, the weather outside or the level of crowding in the shop might affect helping behavior rather than the type of shop itself (1 mark).

**(a)**
- 1 mark: IV: Type of shop (small independent vs. large supermarket)
- 1 mark: DV: Helping behavior / frequency of helping.

**(b)**
- 1 mark: First behavioral category (must be objective and observable, e.g., holding a door open).
- 1 mark: Second behavioral category (must be objective and observable, e.g., picking up dropped items).
- *Note: Reject vague categories like 'being nice' or 'smiling'.*

**(c)**
- 1 mark: Use of two observers recording independently at the same time.
- 1 mark: Correlating their scores / calculating percentage agreement (should be high, e.g., 0.80+).

**(d)**
- 1 mark: Identification of a relevant weakness (e.g., lack of control, risk of observer bias).
- 1 mark: Contextualisation of this weakness to the store helping scenario.

**(a) Directional hypothesis [2 marks]**
- 1 mark for stating a directional relationship.
- 1 mark for operationalizing both the IV (doodling vs non-doodling) and the DV (concentration/recall score).
- *Example:* Children who doodle while listening to the auditory tape will recall more names/places than children who do not doodle.

**(b) Why independent measures instead of repeated measures [2 marks]**
- 1 mark for identifying a limitation of repeated measures (e.g., order effects, practice effects, demand characteristics).
- 1 mark for applying this specifically to the doodling/auditory task.
- *Example:* If children did both conditions, they would experience practice effects (1 mark). They would hear the same story or list twice, meaning their second recall score would be better because they already heard it, not because of the doodling condition (1 mark).

**(c) Standardisation feature [2 marks]**
- 1 mark for identifying a standardisation feature (e.g., same recording, same instructions, same environment).
- 1 mark for explaining how this controls a situational variable in this specific study.
- *Example:* Elena should use a standardised pre-recorded message played at the exact same volume (1 mark). This ensures that variation in speech delivery or volume does not affect concentration levels across participants (1 mark).

**(d) Ethical issue with children and how to address it [2 marks]**
- 1 mark for identifying the specific ethical issue (consent/vulnerability/understanding).
- 1 mark for explaining the appropriate solution (parental consent/assent).
- *Example:* Children aged 7-8 cannot legally consent for themselves (1 mark). Elena must obtain written informed consent from their parents or legal guardians before the study begins (1 mark).

**(a)**
- 2 marks: Clear directional hypothesis with fully operationalized IV (doodling vs non-doodling) and DV (recall/concentration).
- 1 mark: Directional hypothesis but with weak operationalization.
- *Note: Reject non-directional or null hypotheses.*

**(b)**
- 1 mark: Identifies a relevant reason (e.g., avoids practice effects / order effects).
- 1 mark: Explains the reason in context (e.g., hearing the same tape twice would lead to automatic improvement).

**(c)**
- 1 mark: Suggests a specific standardised procedure (e.g., same headphone volume, same instructions, same length of doodling sheet).
- 1 mark: Explains how it controls a potential confounding situational variable.

**(d)**
- 1 mark: Identifies ethical issue related to children (e.g., inability to give informed consent, susceptibility to stress).
- 1 mark: Proposes an appropriate mitigation (e.g., parental consent, right to withdraw explained simply).

**(a) Strength of correlational design [2 marks]**
- 1 mark for identifying a general strength of correlation (e.g., ethics, practicality, no manipulation of variables).
- 1 mark for applying it to the context of screen time and sleep.
- *Example:* It allows researchers to study variables that would be unethical or impractical to manipulate (1 mark). It would be artificial and difficult to control exactly how much screen time adolescents have before bed in a lab, so correlation allows natural behavior to be measured (1 mark).

**(b) Self-report measure (validity and reliability) [2 marks]**
- 1 mark for describing how to measure sleep quality (e.g., standardized scale, Likert questions).
- 1 mark for explaining how to ensure validity or reliability (e.g., pilot testing, test-retest, clear questions).
- *Example:* Dr. Chen can use a questionnaire with a standardised Likert scale from 1-10 (1 mark) and ensure reliability by using the test-retest method to see if their sleep scores remain consistent over two typical weeks (1 mark).

**(c) Type of correlation and explanation [2 marks]**
- 1 mark for identifying 'negative correlation'.
- 1 mark for explaining what it means in this context (as screen time goes up, sleep quality goes down).
- *Example:* This is a negative correlation (1 mark). It means that adolescents who spend more hours on screens before bed tend to report lower sleep quality scores (1 mark).

**(d) Third variable problem / Cause-and-effect [2 marks]**
- 1 mark for explaining that correlation does not equal causation / presence of a third variable.
- 1 mark for proposing a specific confounding third variable in this context.
- *Example:* A correlation does not establish cause-and-effect because there could be a third variable (1 mark). For instance, academic stress could cause both higher screen time (due to studying/procrastination late at night) and poorer sleep quality due to anxiety (1 mark).

**(a)**
- 1 mark: General advantage of correlations (e.g., good starting point for research, ethical when variables cannot be manipulated).
- 1 mark: Linked to screen time/sleep context.

**(b)**
- 1 mark: Descriptive detail of the self-report tool (e.g., closed questions on a rating scale).
- 1 mark: Explicit link to reliability/validity (e.g., using test-retest or clear operational definitions to avoid misinterpretation).

**(c)**
- 1 mark: Identifies 'negative correlation'.
- 1 mark: Correctly describes the relationship (one variable increases while the other decreases, using the specific variables of screen time and sleep quality).

**(d)**
- 1 mark: Clear explanation of why correlation doesn't prove causation (e.g., bidirectional relationship or third variable problem).
- 1 mark: Contextual example of a possible third variable (e.g., stress, caffeine intake, noise).

Part (a) provides a fully operationalised laboratory observation design with a clear IV, standardisation of the video stimulus, and a behavioral checklist using event sampling. It addresses all four key prompts including sampling, procedure, and reliability/validity controls (such as blind observers and inter-rater checks). Part (b) identifies a valid limitation (low ecological validity) and offers a practical solution (naturalistic observation in a school setting with participant observers) to overcome the limitation, explaining how this modification restores natural behaviors.

Part (a): [10 marks] Level 3 (8-10 marks): The design is highly detailed, fully operationalised, and fully replicable. All four prompts (operationalisation, sampling, procedure, controls) are addressed thoroughly. The design is appropriate for a laboratory observation. Level 2 (5-7 marks): The design is generally sound and covers most prompts, but lacks details in one or two areas (e.g., weak operationalisation of behavioral categories). The study is mostly replicable. Level 1 (1-4 marks): The design is basic, with significant omissions. The student may have chosen an inappropriate method (e.g., a questionnaire instead of observation, max 4 marks). Part (b): [4 marks] 1 mark for identifying a valid limitation (e.g., ecological validity/demand characteristics). 1 mark for explaining why this is a limitation in the context of the study. 1 mark for suggesting an appropriate solution. 1 mark for explaining how this solution resolves the issue.