Describe the shape of a normal distribution.

It is a symmetrical bell-shaped curve, with most scores clustered around the centre and progressively fewer towards each tail.

A set of scores has a mean of 50, a median of 50 and a mode of 50. What does this suggest about the distribution?

It suggests a symmetrical distribution such as the normal curve, since the three measures coincide only when the scores are spread evenly about the centre.

What is a skewed distribution?

An asymmetrical distribution in which the scores bunch towards one end and a longer tail stretches out to the other.

In a positively skewed distribution, where is the long tail and how are the three averages ordered?

The tail stretches to the right, and the mode is lowest, the median in the middle and the mean highest.

In a negatively skewed distribution, where is the long tail and how are the three averages ordered?

The tail stretches to the left, and the mean is lowest, the median in the middle and the mode highest.

OCR A-Level Psychology H567

Research Methods and Techniques

Topic overview Laboratory, field and quasi experiments Evaluating experiments: validity, control and realism Structured, unstructured, naturalistic and controlled observations Participant, non-participant, overt and covert observations Questionnaires, structured interviews and unstructured interviews Semi-structured interviews and evaluating self-reports Correlational research and correlation coefficients

Planning and Conducting Research

Topic overview Aims, research questions and hypotheses Target populations, random and opportunity sampling Self-selected, snowball and stratified sampling Repeated measures design Independent measures and matched participants designs Variables, operationalisation and control of extraneous variables Behavioural categories, coding frames and time sampling Event sampling and inter-rater reliability in observations Closed and open questions, Likert and semantic differential scales Writing questionnaire items: wording, fillers and piloting

Data Recording, Analysis and Presentation

Topic overview Raw data tables, standard form and decimal form Significant figures, estimation and the range Nominal, ordinal and interval data Quantitative, qualitative, primary and secondary data Measures of central tendency Measures of dispersion Percentages, fractions, ratios and graphs Normal and skewed distributions and probability Significance levels, Type 1 and Type 2 errors and critical values Parametric criteria and choosing a non-parametric test Degrees of freedom, choosing a test and mathematical symbols Representativeness, generalisability and types of reliability Types of validity Demand characteristics, social desirability and researcher bias The BPS Code of Ethics and ethical issues in research

Report Writing and Scientific Communication

Topic overview Abstract and introduction of a practical report Method and results sections of a practical report Discussion, references and appendices Harvard referencing of academic sources The role of peer review in validating knowledge

Practical Activities and the Nature of Science

Topic overview Conducting and analysing self-report, observation, experimental and correlational practicals Risk assessment and management in practicals Cause and effect, falsification and replicability Replication, objectivity, induction and deduction Hypothesis testing, manipulation of variables and quantifiable measurements How society makes decisions about science and psychology's contribution to society

Mathematical Requirements for Research Methods

Topic overview Decimal and standard form, percentages and ratios Fractions, percentages and estimating results Significant figures and calculating the mean Median, mode and choosing a measure of central tendency The range and standard deviation Frequency tables, bar charts, histograms and scatter diagrams Correlation coefficients, pie charts and translating between data forms Probability, significance levels and principles of sampling Normal and skewed distributions Selecting an inferential test Critical values and deciding whether a result is significant Calculating chi-square, sign test, Wilcoxon and Mann-Whitney values and reporting results Distinguishing levels of measurement Identifying levels of measurement in quantitative and qualitative data Converting qualitative data and primary and secondary data Order of magnitude estimates and statistical symbols Reporting significance in symbols and substituting into formulae Solving equations for Spearman's rho and chi-square

Studying and Evaluating the Core Studies: The Common Framework

Topic overview Background, aims, design and sample of a core study Procedure, results and conclusions of a core study Comparing classic and contemporary studies in their pairs Individual, social and cultural diversity in paired studies Research methods and techniques across the core studies Types of data and validity across the core studies Reliability, ethics, sampling bias and ethnocentrism across the core studies The five areas of psychology and their key themes Relating each core study to its area of psychology

Core Studies: Social Area

Topic overview Milgram (1963) obedience: background, sample and apparatus Milgram (1963) obedience: procedure, results and conclusions Milgram (1963) obedience: evaluation and applications Bocchiaro et al. (2012) disobedience and whistle-blowing: background and sample Bocchiaro et al. (2012) disobedience and whistle-blowing: procedure, results and conclusions Bocchiaro et al. (2012) disobedience and whistle-blowing: evaluation and applications Responses to people in authority: similarities and differences between Milgram and Bocchiaro et al.Responses to people in authority: what Bocchiaro et al. add to Milgram Piliavin et al. (1969) subway Samaritans: background, design and method Piliavin et al. (1969) subway Samaritans: sample, materials and procedure Piliavin et al. (1969) subway Samaritans: results and findings Piliavin et al. (1969) subway Samaritans: conclusions, the cost-reward model and evaluation Levine et al. (2001) cross-cultural altruism: background, sample and materials Levine et al. (2001) cross-cultural altruism: procedure and results Levine et al. (2001) cross-cultural altruism: conclusions and evaluation Responses to people in need: similarities and differences between Piliavin et al. and Levine et al.Responses to people in need: what Levine et al. add to Piliavin et al.

Core Studies: Cognitive Area

Topic overview Loftus and Palmer (1974) eyewitness testimony: background and the first experiment Loftus and Palmer (1974) eyewitness testimony: the second experiment, conclusions and evaluation Grant et al. (1998) context-dependent memory: background, method and procedure Grant et al. (1998) context-dependent memory: results, conclusions and evaluation Memory: similarities and differences between Loftus and Palmer and Grant et al.Memory: what Grant et al. add to Loftus and Palmer Moray (1959) auditory attention: background, method and sample Moray (1959) auditory attention: procedure, results and findings Moray (1959) auditory attention: conclusions and evaluation Simons and Chabris (1999) visual inattention: background and procedure Simons and Chabris (1999) visual inattention: results, conclusions and evaluation Attention: similarities and differences between Moray and Simons and Chabris Attention: what Simons and Chabris add to Moray

Core Studies: Developmental Area

Topic overview Bandura et al. (1961) transmission of aggression: background, method and sample Bandura et al. (1961) transmission of aggression: materials and procedure Bandura et al. (1961) transmission of aggression: results, conclusions and evaluation Chaney et al. (2004) Funhaler study: background, method and procedure Chaney et al. (2004) Funhaler study: results, conclusions and evaluation External influences on children's behaviour: comparing Bandura et al. and Chaney et al.Kohlberg (1968) stages of moral development: method and the six stages Kohlberg (1968) stages of moral development: findings, conclusions and evaluation Lee et al. (1997) evaluations of lying and truth-telling: background, method and materials Lee et al. (1997) evaluations of lying and truth-telling: procedure, results and conclusions Lee et al. (1997) evaluations of lying and truth-telling: evaluation Moral development: similarities and differences between Kohlberg and Lee et al.Moral development: what Lee et al. add to Kohlberg

Core Studies: Biological Area

Topic overview Sperry (1968) split-brain study: background, apparatus and procedure Sperry (1968) split-brain study: results, conclusions and evaluation Casey et al. (2011) neural correlates of delay of gratification: background and sample Casey et al. (2011) neural correlates of delay of gratification: the go/no-go task and results Casey et al. (2011) neural correlates of delay of gratification: conclusions and evaluation Regions of the brain: comparing Sperry and Casey et al.Blakemore and Cooper (1970) early visual experience: background and method Blakemore and Cooper (1970) early visual experience: procedure and results Blakemore and Cooper (1970) early visual experience: conclusions and evaluation Maguire et al. (2000) taxi drivers: background, method and sample Maguire et al. (2000) taxi drivers: MRI analysis and results Maguire et al. (2000) taxi drivers: conclusions and evaluation Brain plasticity: comparing Blakemore and Cooper and Maguire et al.

Core Studies: Individual Differences Area

Topic overview Freud (1909) Little Hans: background, method and early history Freud (1909) Little Hans: the horse phobia and fantasies Freud (1909) Little Hans: conclusions and evaluation Baron-Cohen et al. (1997) autism in adults: background, method and sample Baron-Cohen et al. (1997) autism in adults: the Eyes Task, control tasks and results Baron-Cohen et al. (1997) autism in adults: further results, conclusions and evaluation Understanding disorders: comparing Freud and Baron-Cohen et al.Gould (1982) bias in IQ testing: background and the army tests Gould (1982) bias in IQ testing: Yerkes's conclusions and how the tests were given Gould (1982) bias in IQ testing: consequences and evaluation Hancock et al. (2011) language of psychopaths: background and procedure Hancock et al. (2011) language of psychopaths: results, conclusions and evaluation Measuring differences: comparing Gould and Hancock et al.

Areas and Perspectives in Psychology

Topic overview The social area: defining principles, Milgram and Bocchiaro et al.The social area: Piliavin et al. and Levine et al.The social area: strengths, weaknesses, applications and comparison The cognitive area: defining principles, Loftus and Palmer and Grant et al.The cognitive area: Moray and Simons and Chabris The cognitive area: strengths, weaknesses, applications and comparison The developmental area: defining principles and Bandura et al.The developmental area: Chaney et al., Kohlberg and Lee et al.The developmental area: strengths, weaknesses, applications and comparison The biological area: defining principles and Sperry The biological area: Casey et al., Blakemore and Cooper and Maguire et al.The biological area: strengths, weaknesses, applications and comparison The individual differences area: defining principles and Freud's Little Hans The individual differences area: Baron-Cohen et al., Gould and Hancock et al.The individual differences area: strengths, weaknesses, applications and comparison The behaviourist perspective: conditioning, reinforcement and observational learning The behaviourist perspective: Bandura et al., the Funhaler study and strengths The behaviourist perspective: weaknesses, applications and comparison with the psychodynamic perspective The psychodynamic perspective: personality structure, psychosexual stages and defence mechanisms The psychodynamic perspective: Little Hans, Kohlberg and Hancock et al.The psychodynamic perspective: strengths, weaknesses and comparison with the behaviourist perspective

Debates in Psychology

Topic overview The nature/nurture debate: concepts, positions and research The nature/nurture debate: applications and comparison with other debates The freewill/determinism debate: concepts, positions and research The freewill/determinism debate: applications and comparison with other debates The reductionism/holism debate: concepts, positions and research The reductionism/holism debate: applications and comparison with other debates The individual/situational debate: concepts, positions and research The individual/situational debate: applications and comparison with other debates The usefulness of research debate: concepts and criteria The usefulness of research debate: research illustrating each position The usefulness of research debate: applications and comparison with other debates The ethical considerations debate: ethical guidelines The ethical considerations debate: cost-benefit analysis and research illustrating ethical issues The ethical considerations debate: positions, applications and comparison with other debates The socially sensitive research debate: concepts and positions The socially sensitive research debate: research, applications and comparison The psychology as a science debate: features of science The psychology as a science debate: positions and supporting research The psychology as a science debate: evidence against, applications and comparison

Practical Applications of Psychology

Topic overview Recognising psychological content and making evidence-based suggestions Evaluating the strengths and weaknesses of your own suggestions

Issues in Mental Health

Topic overview Historical views of mental illness Defining abnormality and categorising mental disorders Rosenhan (1973) on being sane in insane places: background and procedure Rosenhan (1973) on being sane in insane places: results, conclusions and evaluation Characteristics of affective, psychotic and anxiety disorders The biochemical explanation of mental illness Genetic and brain abnormality explanations of mental illness Gottesman et al. (2010) offspring of psychiatrically ill parents: method and risk figures Gottesman et al. (2010) offspring of psychiatrically ill parents: conclusions and evaluation Biological treatments: antipsychotics, SSRIs and ECT Behaviourist and cognitive explanations of mental illness Humanistic, psychodynamic and cognitive neuroscience explanations of mental illness Szasz (2011) the myth of mental illness: mental illness as a metaphor Szasz (2011) the myth of mental illness: objections to coercive psychiatry and evaluation Non-biological treatments: CBT, REBT and systematic desensitisation

Child PsychologyApplied option

Topic overview What psychologists mean by intelligence Biological factors affecting intelligence Van Leeuwen et al. (2008) twin-family study of IQ: background and procedure Van Leeuwen et al. (2008) twin-family study of IQ: results, conclusions and evaluation Assessing intelligence with standardised tests Brain development in childhood and adolescence Impact of brain development on risk-taking behaviour Barkley-Levenson and Galvan (2014) expected value in the adolescent brain: background and method Barkley-Levenson and Galvan (2014) expected value in the adolescent brain: results, conclusions and evaluation Strategies to reduce risk-taking using knowledge of brain development Perceptual development in children and animals Gibson and Walk (1960) the visual cliff Play strategies to develop perception in young children Piaget's theory of cognitive development Impact of Piaget, Vygotsky and Bruner on education Wood et al. (1976) the role of tutoring in problem-solving Cognitive strategies to improve revision and learning Development of attachment in babies Impact of failure to develop attachments Ainsworth and Bell (1970) the Strange Situation: procedure and attachment types Ainsworth and Bell (1970) the Strange Situation: insecure types, conclusions and evaluation Developing an attachment-friendly environment Influence of television advertising on children Stereotyping and materialism in children's advertising Johnson and Young (2002) gendered voices in children's advertising: background and method Johnson and Young (2002) gendered voices in children's advertising: results, conclusions and evaluation Strategies to reduce the impact of advertising aimed at children

Criminal PsychologyApplied option

Topic overview Physiological explanations of criminal behaviour Genetic factors and non-physiological explanations of criminal behaviour Raine et al. (1997) brain abnormalities in murderers: background, procedure and brain findings Raine et al. (1997) brain abnormalities in murderers: further findings, conclusions and evaluation Biological strategies for preventing criminal behaviour Motivating factors and bias in collecting and processing forensic evidence Hall and Player (2008) emotional context and fingerprint analysis: background and method Hall and Player (2008) emotional context and fingerprint analysis: results, conclusions and evaluation Strategies for reducing bias in collecting and processing forensic evidence Collecting and using evidence from witnesses and suspects Memon and Higham (1999) review of the cognitive interview: aims and components Memon and Higham (1999) review of the cognitive interview: findings, conclusions and evaluation Police interview strategies: the cognitive interview and the PEACE model How juries are persuaded by the characteristics of defendants and witnesses Persuading juries: speech style, expert witnesses, order of evidence and publicity Dixon et al. (2002) accent and perceptions of guilt: background and method Dixon et al. (2002) accent and perceptions of guilt: results, conclusions and evaluation Strategies to influence jury decision making Neighbourhood features, broken windows and defensible space Zero tolerance policy and its influence on crime Wilson and Kelling (1982) broken windows: foot patrols and the abandoned car demonstration Wilson and Kelling (1982) broken windows: the argument, recommendations and evaluation Environmental strategies for crime prevention Aims of punishment Effects of imprisonment and reform as responses to offending Haney et al. (1973) simulated prison study: background, procedure and the prisoners' rebellion Haney et al. (1973) simulated prison study: results, conclusions and evaluation Strategies for reducing reoffending

Environmental PsychologyApplied option

Topic overview Environmental stressors and the stress response Crowding, heat and pollution and their impact on biological responses Black and Black (2007) aircraft noise, stress and hypertension: background and method Black and Black (2007) aircraft noise, stress and hypertension: results, conclusions and evaluation Strategies for managing environmental stress Types of biological rhythm and how they are controlled Impact of disrupting biological rhythms on behaviour Czeisler et al. (1982) rotating shift schedules: background, method and sleep findings Czeisler et al. (1982) rotating shift schedules: outcomes, conclusions and evaluation Strategies for reducing the effects of jet lag and shift work Conservation behaviours, attitudes and social norms Feedback, prompts, framing and other factors that influence conservation Lord (1994) message and source strategies for recycling: background and method Lord (1994) message and source strategies for recycling: results, conclusions and evaluation Techniques to increase recycling and other conservation behaviour Cognitive overload and display design Vigilance, alarms and the impact of observation in the workplace Drews and Doig (2014) configural vital sign display: background and procedure Drews and Doig (2014) configural vital sign display: results, conclusions and evaluation Workplace design based on ergonomic research Impact of the built environment and defensible space Urban renewal, housing and wellbeing Ulrich (1984) view through a window and recovery from surgery: background and method Ulrich (1984) view through a window and recovery from surgery: results, conclusions and evaluation Environmental design to improve health and wellbeing Personal space and proxemics Territory and personal space in the workplace Wells (2000) office personalisation: background, method and gender differences Wells (2000) office personalisation: wellbeing, company policies and evaluation Office design strategies based on territory and personal space

Sport and Exercise PsychologyApplied option

Topic overview Arousal, anxiety, drive theory and the inverted-U hypothesis Optimal arousal and measuring anxiety in sport Fazey and Hardy (1988) catastrophe model: criticisms of the inverted-U and the cusp model Fazey and Hardy (1988) catastrophe model: predictions, conclusions and evaluation Techniques for managing arousal and anxiety in sport Benefits of exercise to mental health Lewis et al. (2014) dance and mood in Parkinson's disease: background and procedure Lewis et al. (2014) dance and mood in Parkinson's disease: results, conclusions and evaluation Exercise strategies to improve mental health Self-efficacy, sports confidence, sport orientation and imagery Munroe-Chandler et al. (2008) imagery and confidence in youth football: background and procedure Munroe-Chandler et al. (2008) imagery and confidence in youth football: results, conclusions and evaluation Strategies for motivating athletes Personality, its measurement and its relationship to sport Kroll and Crenshaw (1970) personality profiles of four athletic groups: background and procedure Kroll and Crenshaw (1970) personality profiles of four athletic groups: results, conclusions and evaluation Using knowledge of personality to improve sports performance Teams, cohesion, coaching and leadership Smith et al. (1979) coach effectiveness training: background and procedure Smith et al. (1979) coach effectiveness training: results, conclusions and evaluation Strategies for improving team performance How an audience can facilitate or inhibit sports performance Home advantage and audience effects in sport Zajonc et al. (1969) social facilitation in cockroaches: background and procedure Zajonc et al. (1969) social facilitation in cockroaches: results, conclusions and evaluation Training for and playing in spectator sports

Methodological Issues and Debates Running Through Applied Psychology

Topic overview Nature and nurture across applied psychology Freewill, determinism, reductionism and holism across applied psychology Individual and situational explanations across applied psychology Usefulness of research in applied psychology Psychology as a science across applied psychology Ethical considerations in applied research Conducting socially sensitive research in applied psychology Ethnocentrism across applied psychology Validity in the key research of applied psychology Reliability and sampling bias in the key research of applied psychology How different areas and perspectives explain applied topics Social, moral, cultural and spiritual issues raised by the applied topics How the key research contributes to understanding individual, social and cultural diversity How society decides about scientific issues and psychology's contribution to the economy

Mathematical Requirements for Research Methods

Normal and skewed distributions

1 thing to know
Component 01

Overview

Recall questions on the shape of normal distributions, the proportion of scores within one standard deviation, positively and negatively skewed distributions and the order of their averages, and why distribution matters.

What you need to know

Answer each one before you reveal it.

Your recallNot started

Key term

Why does it matter whether a set of scores is normally distributed?

Questions from this subtopic

Each one with the model answer underneath.

1
Describe the shape of a normal distribution.
Model answer
It is a symmetrical bell-shaped curve, with most scores clustered around the centre and progressively fewer towards each tail.
2
A set of scores has a mean of 50, a median of 50 and a mode of 50. What does this suggest about the distribution?
Model answer
It suggests a symmetrical distribution such as the normal curve, since the three measures coincide only when the scores are spread evenly about the centre.
3
Roughly what proportion of scores in a normal distribution lie within one standard deviation of the mean?
Model answer
About 68% of the scores.
4
What is a skewed distribution?
Model answer
An asymmetrical distribution in which the scores bunch towards one end and a longer tail stretches out to the other.
5
In a positively skewed distribution, where is the long tail and how are the three averages ordered?
Model answer
The tail stretches to the right, and the mode is lowest, the median in the middle and the mean highest.
6
In a negatively skewed distribution, where is the long tail and how are the three averages ordered?
Model answer
The tail stretches to the left, and the mean is lowest, the median in the middle and the mode highest.

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Research Methods and Techniques

Planning and Conducting Research

Data Recording, Analysis and Presentation

Report Writing and Scientific Communication

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APunishment requires deprivation, loss of autonomy and stigma.

BReform requires trust, responsibility and self-respect.

CThe regime that achieves one tends to undermine the other.

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Range means the highest score minus the lowest score.

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