Research methods Mark Scheme answers -
24-Write a non-directional hypothesis for this study. (2 marks)
'There is an association between birth order and choice of career' = 2 marks A directional hypothesis is not creditworthy. Reference to a relationship/correlation cannot gain credit. Although technically, the psychologist is looking for an association, candidates can gain credit for expressing the hypothesis in terms of a difference eg 'There is a difference in career choice depending on birth order.'
Explain how the psychologist might measure the dependent variable (3)
1 mark for a practical idea, 2 further marks for increasingly detailed outline of how the DV would be measured. 3 marks for a practical idea that is fully explained. Dependent variable: this is a measure of helping behaviour, so there is a range of possibilities. Eg Friends and family could be asked to rate the helpfulness of the participant eg on a scale from 1-10; alternatively a scenario could be set up without the pps knowledge to observe their helping behaviour e.g. a confederate of the researcher drops books, and the number of people helping/not helping is recorded. There are further ways of operationalizing helping behaviour, but they must be practical and feasible to receive credit. Merely naming a research method eg interview, questionnaire receives not credit. No credit can be awarded for unethical suggestions or really impractical suggestions
Explain how the two psychologists might have assessed the reliability of their content analysis. (3)
1 mark for identification of an appropriate way of assessing reliability in this investigation. By far the most likely answers here are inter-rater reliability or test-retest reliability. 2 marks for some explanation/elaboration: 'the two psychologists could carry out content analysis of the films separately and compare their answers' or 'they could re-code the films at a later date and compare the two sets of data'. Mark Scheme - General Certificate of Education (A-level) Psychology A - PSYA4 - June 2013 30 3 marks for an accurate and clear explanation which refers to deriving the categories and checking the data. 'The two psychologists could watch the films separately and devise a set of categories. They could compare these and use categories they both agreed on. They could carry out content analysis of the films separately and compare their answers looking for agreement'.
Identify an appropriate statistical test to check the inter-rater reliability of these two observers. Explain why this is an appropriate test. (3)
1 mark for identifying the appropriate test - Spearman's Rho or Pearson's (with appropriate justification). 2 further marks for explaining why it is appropriate ie the psychologist is testing for a correlation and the data that can be treated as ordinal. Candidates can gain no marks on this question if their choice of statistical test is inappropriate.
Identify an appropriate statistical test that the psychologist could use and justify your choice. (3)
1 mark for the identification of an appropriate test, 2 further marks for the justification. • A test of difference is required. • An independent groups design. • A test appropriate to the level of measurement. If the data can be treated as at least ordinal then a Mann Whitney U test would be appropriate; if the data can be categorised then a Chi Square could be used. Credit also appropriate reference to the independent t-test. The test must be correct for justification for marks to be awarded.
Why was it considered a type one error?
3 marks for a clear explanation which is based on comparison of the calculated value of rs with the critical value at the 0.01 level of significance and indicates competence in use of statistical tables as follows: A Type 1 error is unlikely because the calculated value of rs (-0.52) exceeds the critical table value at both the 0.05 and 0.01 level for a one-tailed test. The chance of a Type1 error occurring is therefore less than 1%. This means that the researchers can be 99% certain that the results obtained are not due to chance. Award one mark for a brief explanation (It is significant at 0.01). Award two further marks for an explanation which refers to two of the above points.
What is meant by a 'Type 1 error'? Explain why the psychologist thought that she had not made a Type 1 error. - 4 marks
A Type 1 error is when the results are accepted as significant when in fact they are not; the alternative hypothesis is accepted when it is false. Accept definitions in terms of null hypothesis. Up to 3 marks for explanation which might include: • The results are significant at p<0.01 • p<0.01 is a stringent level of significance. • The more stringent the significance level the less the chance of a Type 1 error. • The likelihood of the psychologist making a Type 1 error is 1 in 100 or less.
Write a suitable directional hypothesis for this investigation. (3 marks)
A suitable directional hypothesis would be 'There is a negative correlation (relationship) between age and recall accuracy rating'. 3 marks for a fully operationalised hypothesis as above 2 marks for a directional correlational hypothesis that identifies age and recall as the two variables but is not fully operationalised 1 mark for a directional hypothesis where the variables are not identified ('there will be a negative correlation') or where the hypothesis lacks clarity. Award zero marks for a non-directional or null hypothesis or any hypothesis predicting a difference or association.
(g) What is meant by reliability? Explain how the reliability of the scores in this study could be checked. (4 marks)
AO1: One mark for brief description, eg 'consistency' and one further mark for elaboration. Reliability refers to consistency over time. If a test, questionnaire, etc, is reliable, people tend to score the same on the test if they take it again soon afterwards. AO2/3: One mark for a very brief answer, eg 'do another test' or 'test them again' or 'use another interviewer to check'. Two marks for some elaboration. Reliability could have been checked by administering a valid and reliable questionnaire to the participants as well as interviewing them and then comparing the scores on the two measures. If the interview score was reliable, there would be strong positive correlation between the scores. The interviews could have been filmed and given to another trained therapist to assess. A strong correlation between the scores given by each therapist would demonstrate reliability.
What is it meant by peer review.
AO2/3= 5 marks Peer review is an important part of this process because it provides a way of checking the validity of the research, making a judgement about the credibility of the research and assessing the quality and appropriateness of the design and methodology. Peers are also in a position to judge the importance or significance of the research in a wider context. They can also assess how original the work is and whether it refers to relevant research by other psychologists. They can then make a recommendation as to whether the research paper should be published in its original form, rejected or revised in some way. This peer review process helps to ensure that any research paper published in a well-respected journal has integrity and can, therefore, be taken seriously by fellow researchers and by lay people.
The teacher noticed that most of the students who were rated highly on musical ability were left-handed. The teacher is aware that her previous definition of musical ability lacked validity. Design a study to test whether there is a difference in the musical ability of left-handed students and right-handed students. You have access to a sixth form of 200 students. You should: identify the design that you would use explain an appropriate sampling method and justify your choice describe the procedure that you would use, including details of how you would assess musical ability write a suitable debrief for these participants.
AO2/AO3 = 10 marks In question 23, candidates are asked to design a study to test if there is a difference between left-handed and right-handed students in musical ability. Design - 1 mark • Award 1 mark for identification of an appropriate design (independent measures or matched pairs). Sampling - 2 marks • Award 1 mark for explaining an appropriate sampling method and 1 further mark for justifying why this method would be appropriate. As left-handed people are less common in the population than right-handed people this needs to be addressed in the sampling method. Procedure and assessment of musical ability - 4 marks Award 1 mark for procedure, 1 mark for assessing musical ability and two further marks for elaboration of either or both of these. • Description of the procedure eg each participant will be given a standardised musical ability test, participants should be tested within a controlled environment, with minimal noise or distraction. • Students are required to suggest a plausible alternative method of assessing musical ability to the one in the stem (eg singing a short, novel phrase played on the piano). Further credit could be given for stating that the test should be identical for all students or for explaining how it will be assessed. Debrief - 3 marks • Award up to 3 marks for writing a debrief. This could include the aim of the study, thanking participants for taking part, asking if they have any questions, relevant ethical considerations. • If this is not suitable to be read out to participants, maximum
A Spearman's rho test was used to analyse the data. Give two reasons why this test was used. (2 marks)
Award 1 mark each for any two of the following reasons: Study is looking for a correlation (relationship) Suitable for pairs of scores The data type obtained is ordinal, at least ordinal or interval level Linear relationship between scores
Write an operationalised non-directional hypothesis for this study.
Award 2 marks for an appropriate non-directional hypothesis which is operationalised. 'There is a relationship between happiness scores on a questionnaire and intelligence test scores'
Imagine that you are writing up the report for this experiment. What is the purpose of the abstract in a psychological report?
Award one mark for a brief answer ('the purpose of an abstract is to provide a short summary of the study') and two marks for a detailed answer referring to providing sufficient information to establish if the full report is worth reading.
What is meant by 'validity'? How could the psychologist have assessed the validity of the questionnaire used to measure the severity of symptoms? (4)
Award one mark for a definition of validity. Three further marks for describing how validity of the questionnaire could be assessed. Possible methods include: • Taking another measure of symptoms from the same participants (eg Doctor or family member) and comparing the two sets of scores. If the scores agree, the questionnaire has high validity(concurrent validity) • Ask an expert(s) in the field to assess the questions to see if they are an accurate measure of panic attacks (content validity) • Assess how closely the questions relate to underlying theoretical constructs (i.e. how well they relate to panic symptoms) - construct validity. Less rigorous methods include looking at the questions to see if they appear valid 'on the face of it' (face validity). Students can achieve two marks by providing information about one or more appropriate methods in outline. Three marks can be awarded when answers provide clear description of the entire process of checking validity. Eg: 'Validity refers to whether or not the questionnaire measures what it is supposed to measure (1 mark). Concurrent validity would involve getting a family member to assess the symptoms (1 mark) and seeing how closely they match the score on the questionnaire (1 mark). If the two matched, the questionnaire would have high validity (1 mark). No marks for simply naming types of validity.
Research has shown that music can affect the ability to concentrate. Design an experiment that could be carried out in a classroom to test the effects of two different kinds of music on a task requiring concentration (eg word search). You must use a repeated measures design. In your answer you should: fully operationalise the independent and dependent variables provide details of how you would control extraneous variables describe the procedure that you would use. You should provide sufficient detail for the study to be carried out.
Candidates are required to design an experiment to test the effects of different kinds of music on concentration. Examiners need to ensure that they read the completed answer thoroughly before starting to award marks. Candidates are directed to three pieces of material which should be included within their proposed design. They are required to: operationalise the independent and dependent variables provide details of how they would control extraneous variables Describe the procedure they would use with sufficient detail for the study to be carried out. Candidates are told that they must use a repeated measures design. If they do not, they can only access marks for the IV and DV. In this experiment: IV and DV - 2 marks The independent variable is type of music (for example classical and rock). Candidates should suggest two different types of music. The dependent variable is a measurement of concentration. Candidates can use the suggested word search task but must state how it is to be measured (for example, time taken to complete a word search or number of errors made). Alternatively, candidates may suggest their own DV. Award one mark for operationalising each variable. Controls - 4 marks An important element in a repeated measures design is the control of order effects. Counterbalancing is the most likely procedure to control order effects. Half of the participants should carry out the 1st concentration task with music 1 followed by the 2nd task with music 2. The other half should complete the concentration task with music 2 first and follow this with music 1. The two concentration tasks should be matched for difficulty. Alternatively candidates could argue for randomisation or a time delay between the tasks. Other relevant controls eg volume of music, time allocated for task should be credited. Answers which make no reference to the control of order effects maximum 2 marks. Procedure - 4 marks Procedural information should provide detail of how to go about conducting the study (ie what participants are required to do). Candidates could approach this task at a macro level ie from getting consent to debriefing or at a micro level ie the specific procedure for one participant. Other creditworthy material could include: Dealing with ethical issues Sampling Details of conditions and allocation to them Standardised instructions Data collected Note: there are only 4 marks available for the procedure and therefore candidates do not need to address all of the above to gain full credit.
Explain why the psychologists chose to use a repeated measures design in this experiment. (3)
Candidates can cover one reason explained in detail here or several reasons in less detail. A repeated measures design was chosen in this experiment: • to remove the effects of individual differences in reaction times which would occur if an independent groups design was used • to avoid the potential difficulties involved in matching participants • to reduce the number of participants required for the experiment.
Explain why the teacher's personal opinion cannot be accepted as scientific evidence. Refer to some of the major features of science in your answer.
Candidates need to show that they understand what differentiates opinion from scientific evidence. They could mention some of the following: • The teacher has only experienced one school in a particular catchment area so she has only observed a very limited number of 5 year-olds (issues of sampling and replicability). • She has found out that children do not eat anything nourishing simply by chatting with the children. She has no corroborative evidence from eg parents (issues of objectivity). • She uses vague phrases such as 'decent breakfast' without being clear what this means (operationalisation). • She has generated a theory and made predictions based on flimsy evidence. • She has not used any scientific method to lead to her conclusions eg a carefully controlled experiment, survey or observation. • She has drawn conclusions about the effects of breakfast without considering other variables which might affect reading skills and behaviour.
18----- What is the purpose of the introduction section of a report? (2 marks
Candidates need to show understanding of reporting conventions. The introduction is an important part of the report that provides background information on theories and studies relevant to the investigation. One mark for a brief explanation of the purpose eg 'It provides background information', and one further mark for elaboration or for other detail such as reviewing methodological issues or how the current aims/ hypothesis were derived.
23--- Write a set of standardised instructions that would be suitable to read out to participants in this experiment. (5 marks)
Candidates need to use the details in the description of the study to write an appropriate set of instructions for potential participants. The instructions should be clear and succinct. They must: • explain the procedures of this study relevant to participants • include a check of understanding of instructions They should also use language appropriate for a formal document and be as straightforward and courteous as possible. This is not a consent form so explicit references to ethical considerations are not necessary for full marks. However, it is perfectly acceptable to include comments such as 'you are free to withdraw from the study at any time.'
The psychologist needed to obtain informed consent from her participants. Write a brief consent form which would be suitable for this study. You should include some details of what participants could expect to happen in the study and how they would be protected. (5 marks)
Candidates should demonstrate understanding of some of the requirements of a good consent form. For full marks, it should be succinct, clear and informative. It is likely to include some of the following information:treatment programme that is noninvasive; requirement to be assessed on current level of functioning; use of a trained therapist to conduct interviews; duration of the programme; requirement for re-assessment at the end of the programme; random allocation to a treatment or no-treatment group. It should show awareness of ethical considerations, eg • no pressure to consent - it will not affect any other aspects of their treatment if they choose not to take part • they can withdraw at any time • they can withdraw their data from the study • their data will be kept confidential and anonymous • they should feel free to ask the researcher any questions at any time • they will receive a full debrief at the end of the programme. For full marks, candidates must include a range of both procedural and ethical points
What is content analysis? (2)
Content analysis is a technique for analysing qualitative data of various kinds. Data can be placed into categories and counted (quantitative) or can be analysed in themes (qualitative).
Explain limitations of using random sampling in this study
Even if a sample is random, it may not be truly representative of the population eg might all come from the same school, or be all boys or all girls. • Practical limitations eg the time and effort needed to write out 400 slips for the manual method. • Difficulties of obtaining a truly random sample eg even if the sample is selected randomly, parents might refuse to allow their children to participate. Any plausible and appropriate answers should be credited. Up to 2 marks for identification of limitations. For 3 marks, one or more limitations must be explained in reasonable detail.
Explain how one factor in this experiment might affect its external validity. (3 marks)
External validity refers to how far the findings of the experiment can be generalised to real-life situations. The most likely answer here is that the hazard perception test was done using a computer test which does not resemble real-life driving situations. (No noise, stress, etc.)
Explain how you would analyse the qualitative data from the interviews. (5 marks)
Five marks are awarded for the explanation of how the qualitative data would be analysed. A maximum of one mark should be awarded for identifying one or more appropriate methods and a further four marks for explanation of how the analysis would be carried out. There are many different methods for analysing qualitative data and examiners should read the material presented carefully. Two common methods include: • Content analysis; this method would involve identifying important categories from a sub sample of interview responses (for example references to homework or warmth in the therapist). The researchers would then work through the written data, counting the number of occurrences of each of the categories to produce quantitative data • Thematic analysis: This method would involve reading and rereading (familiarisation) the written transcripts carefully. Coding would involve looking for words which cropped up repeatedly in transcripts. These could then be combined to reduce the number of codes into three or four themes. The data would stay in qualitative format and would not be reduced to numbers.
(h) The psychologist noticed that female and male participants seemed to have responded rather differently to the treatment. She decided to test the following hypothesis: F emale patients with an eating disorder will show greater improvement in their symptoms after treatment with the new therapy than male patients. She used a new set of participants and, this time, used self-report questionnaires instead of interviews with a therapist. Imagine that you are the psychologist and are writing up the report of the study. Write an appropriate methods section which includes reasonable detail of design, participants, materials and procedure. Make sure that there is enough detail to allow another researcher to carry out this study in the future
For full marks, the method section should be written clearly, succinctly and in such a way that the study would be replicable. It should be set out in a conventional reporting style, possibly under appropriate headings. Examiners should be mindful that there are now different, but equally acceptable reporting styles. For example, candidates should not be penalised for writing in the first person. The important factor here is whether the study could be replicated. There should be reasonable detail with regard to: • design • participants • materials • procedures.
What is meant by 'reliability'? Explain how the psychologist might assess the reliability of her questionnaire. (4)
Generic definitions of reliability, eg linking reliability to consistency of findings, data, or participant responses, sufficient for 1 mark. Reliability may also be defined in terms of types of reliability eg internal or external. Merely naming internal/external reliability is not creditworthy. Internal reliability means that the items making up the questionnaire are assessing the same characteristic; external reliability means that the same person taking the questionnaire at two different times produces the same score. Split-half (Internal reliability): scores on half the items (1 mark), are correlated with scores on the other half (1 mark) and the higher the correlation the more reliable the questionnaire (1 mark). • Test-retest (External reliability): the questionnaire is given to the same participants again (1 mark). The scores on the two tests are correlated (1 mark) and the higher the correlation the more reliable the questionnaire (1 mark).
psychologist used a random sampling method. Explain how he could have obtained his sample using this method. (3 marks)
In a random sample, every member of the identified population has an equal chance of selection. In this case, the sampling frame consists of the 400 five-year-old children attending ten local schools. In order to obtain a simple random sample, the researcher has to have the names of all 400 children and can then select using one of the following methods Random number tables - random number tables are specially devised to meet the following criteria - they contain strings of numbers where each number has the same chance of being selected as any other and each number is independent of the others. Such tables are readily available in statistics text books etc or can be generated by the researcher using a computer program. The researcher assigns each child a number between 1 and 400. He enters the table at any place (he could close his eyes and point with a finger at a starting place) and then moves either horizontally or vertically to produce a string of random numbers. He records all the numbers which correspond to the 400 children until he has recorded a total of 100 non-duplicated numbers. • Computer selection - This is a similar method where the computer does most of the work. A computer can generate an endless string of random numbers ie numbers which have no relationship to one another as a sequence. Each child's name is given a number and a random number generator program is used to produce the required sample size (in this case 100 participants). • Manual selection - Using this method, the researcher has to put each name (or an assigned number) on a separate slip of paper and place them all in a container. The researcher then selects 100 slips from the container. The following conditions could apply: the container should be shaken between each draw; the slips of paper should all be the same size and folded in the same way so that one does not feel different from another; the selector draws 'blind' ie cannot see the actual slips of paper.
The psychologist asked the 60 patients for fully informed consent to take part in this trial. What should the psychologist have told the patients so that they were able to give their consent? (5)
In order to gain fully informed consent for this trial, patients should be informed of key information provided in the stem about the clinical trial. • They will be allocated to one of the conditions and they may not receive therapy • If they do receive therapy it will be Cognitive Behavioural • The time period for the study (ie up to 12 weeks) In addition, students could refer to other relevant ethical information such as: • Data should be anonymised so they are not identifiable in the results • Patients should be made aware that they are free to withdraw themselves or their data from the clinical trial if need be • They may be asked to complete homework assignments outside the therapy sessions. For five marks, students must cover the top three bullet points. Answers focus only on g
What does It mean by the term validity?
In this question, candidates are not required to relate validity to this particular study so a general definition of validity is acceptable. Definitions of specific types of validity (eg population validity) can also gain credit. Validity refers to how well a test or a piece of research measures what it says it measures = 1 mark.
Explain how one factor in this study might affect its internal validity and how one factor might affect its external validity. - 4
In this question, candidates have to make their answers relevant to this particular study. Candidates need to make it clear which factor refers to internal and which to external validity. Where candidates do not make this clear, examiners should accept the first factor as referring to internal validity and the second to external validity. For each factor, one mark for a brief explanation and one further mark for elaboration. Factors that might affect internal validity include: • Individual differences eg colour blindness could have affect the outcome as the studies were all independent groups design • possibility of experimenter bias in judging the creativity of the ideas. 'Individual differences' = 1 mark 'Because the researchers used an independent groups design, there could be a problem with individual differences' = 2 marks Factors that might affect external validity include: • sampling bias - all participants were university students • cultural bias - study took place in Canadian university - response to colours might well be affected by cultural factors 'sample bias' - 1 mark 'There was a sampling bias. Although all the participants were university students the investigators drew more general conclusions = 2 marks
What is meant by internal validity? (1)
Internal validity refers to how accurately a test or measuring instrument measures what it says it measures. Award one mark for a clear definition. Award no marks for truth, truth value or accuracy.
He could have used a matched pairs design. Explain why this design would have been more difficult to use in this study
It would have been more difficult to use a matched-pairs design because of the number of relevant factors that would need to be controlled (eg gender, intelligence, parental attitudes/income/education, experience of pre-school education, number of siblings in family etc). There is a relatively small pool of children available (ie 400) and it could be difficult to match on all these factors. It would also be very time-consuming; it could be quite expensive to carry out the necessary surveys; it could be quite intrusive collecting such information from parents.
The psychologists were careful to consider the issue of reliability during the study. What is meant by reliability?
One mark for an accurate definition: The extent to which results or procedures are consistent or simply 'consistency'
The psychologists decided to propose a directional hypothesis. Why was a directional hypothesis appropriate in this case? (1 mark)
One mark for an accurate reason: The decision to use a directional hypothesis was based on findings of previous research which pointed to an effect in a particular direction ie memory is poorer with age
Identify an appropriate statistical test that the psychologists could use to analyse the data from the follow-up study. Give one reason why this test is appropriate
One mark for correctly identifying the Mann Whitney U test or independent t test • One mark awarded for an accurate reason for choice (for Mann Whitney these are: test of difference, independent groups design/independent data or data which can be treated at an ordinal level)
Give two reasons why the psychologists used Spearman's rho to analyse the data. (2 marks
One mark for each accurate reason given: the researchers are testing for a correlation or a relationship between two variables the data is to be treated as ordinal because the recall accuracy is in the form of ratings
Explain how the psychologists might have assessed the reliability of their ratings. (3 marks)
One mark for identification of a way of ensuring reliability. By far the most likely answer here is inter-rater reliability. Two marks for some explanation/elaboration: using two separate psychologists and comparing them. Three marks for an accurate and clear explanation: using two separate psychologists to rate the typed accounts for accuracy and comparing/correlating the ratings to see how similar they are. Candidates could make a case for test retest which would involve the same psychologist reexamining the ratings after a period of time
Other than parental consent, identify one ethical issue raised in this study and explain how the psychologist might address it.
One mark for identifying an appropriate issue and second mark for explaining how it could be addressed. The most likely issue is confidentiality which could be addressed by ensuring that all scores on reading scales and all personal information are anonymised. There are also ethical problems involved in denying the control group breakfast although it is more difficult for candidates to suggest a way of addressing this - perhaps to put only those children into the control group who do not eat breakfast anyway, restricting the study length to a short period of time and, if the study results support the hypothesis, to provide free breakfasts to these children for the rest of the academic year. Parental consent is excluded because it is given in the stem so answers which offer this as an issue cannot gain credit.
Explain why peer review is important in psychological research.
Peer review is an important part of this process because it provides a way of checking the validity of the research, making a judgement about the credibility of the research and assessing the quality and appropriateness of the design and methodology. Peers are also in a position to judge the importance or significance of the research in a wider context. They can also assess how original the work is and whether it refers to relevant research by other psychologists. They can then make a recommendation as to whether the research paper should be published in its original form, rejected or revised in some way. This peer review process helps to ensure that any research paper published in a well-respected journal has integrity and can, therefore, be taken seriously by fellow researchers and by lay people.
Outline what is meant by the term peer review in psychological research. (2 marks)
Peer review is the process by which psychological research papers, before publication, are subjected to independent scrutiny by other psychologists working in a similar field who consider the research in terms of its validity, significance and originality
What is meant by peer review? (2 marks)
Peer review is the process of subjecting a piece of research to independent scrutiny by other psychologists working in a similar field who consider the research in terms of its validity, significance and originality. 0
Explain why peer review is an important aspect of the scientific process. (4 marks)
Peer reviewed research may be accepted, sent back for revisions or rejected. Peer review is an important part of the scientific process because: It is difficult for authors and researchers to spot every mistake in a piece of work. Showing the work to others increases the probability that weaknesses will be identified and addressed. It helps to prevent the dissemination of irrelevant findings, unwarranted claims, unacceptable interpretations, personal views and deliberate fraud. Peer reviewers also judge the quality and the significance of the research in a wider context. This process ensures that published research can be taken seriously because it has been independently scrutinised by fellow researchers.
The psychologist used a Mann-Whitney test to analyse the data. Give two reasons why he chose this test.
Reasons are: • a test of difference • data (scores from a reading test) are at least ordinal, this would include ordinal/interval and/or ratio • independent design
16 Explain what is meant by replicability. Why is replicability an important feature of science? (5 marks)
Replicability is the ability to check and verify scientific information. Candidates could explain replicability as: • the ability to repeat the method to assess if similar findings are achieved • the ability to achieve similar findings Award 1 mark for a brief definition of replicability. Tautological definitions eg merely stating that 'replicability is the ability to replicate' should not be awarded credit. Replicability is an important part of the scientific process. Scientific method involves defining a problem and formulating a hypothesis which is tested with empirical research. Research findings are an important part of this process. If we wish to draw conclusions from research studies, the procedures and findings should be repeatable. Unrepeatable results may imply flaws or lack of control within the method used and are of limited use in theory construction. Award up to 4 marks for an explanation of why replicability is important. This is likely to be contextualised within a description of the scientific method
Why is replication good for this study?
Replication is an important tool in the scientific method. It allows scientists to check findings and ensure that they are robust. In this study, replication is important, as the original sample is small (30 people) and specific (experienced police drivers). For this reason, replication on a larger sample will be used to check if findings apply outside this specific group.
The psychologist needed to be sure that his participants understood the nature of the study so that they were able to give informed consent. Write a consent form which would be suitable for this study. Make sure there is sufficient information about the study for the participants to make an informed decision. (5 marks)
The form would need to contain sufficient information for the participant to make an informed decision about whether to take part or not. The form should contain some of the following: • The purpose of the study • The length of time required of the participants • The fact that participants would have to be isolated in a research institute for the duration of the study • Details about the diet • Right to withdraw • Reassurance about protection from harm e.g. the availability of medical supervision • The requirement to undertake a series of psychological tests • Reassurance about confidentiality of the data
Explain one or more limitations of the student's proposal and suggest how the investigation could be improved.
The independent variable (exercise) is not operationalised. There is no attempt to specify the amount of exercise taken, frequency or intensity. These could vary substantially. The DV (happiness) is measured through an interview. Interviews are prone to demand characteristics and social desirability effects. Both of these could affect the validity of the measurement. Students may suggest using a happiness questionnaire to measure the DV. As the student proposes to carry out the interviews herself, there is a likelihood of investigator effects. An independent interviewer could be used to reduce this. There is a lack of a control group for comparison purposes. The experiment could be modified to use an independent group design, with a control group who do not undertake an exercise programme. The use of a volunteer sample means that the study is unlikely to be representative. Ethical issues - although a volunteer sample has been recruited, there is no mention of informed consent, confidentiality, debriefing etc. Competence, the student is unlikely to have received training to carry out interviews of this nature. In
Explain how the teacher could have checked the reliability of the mathematical ability test. (3 marks
The main issue is that the teacher has made up her own test: • This involved subjective judgement on the part of the teacher who rates the students' musical ability. Her judgement may not reflect real differences in musical ability and is likely to differ from other people's judgement and/or any absolute criteria for tunefulness. • Lack of reliability in rating musical ability would compromise the validity of the measure. • As the students can choose the song they will sing, the rating of ability could reflect the teacher liking/dislike of the song rather than the student's ability. • The rating may be invalid as the students selected songs which varied in difficulty so the tunefulness reflected the difficulty of the song not the students' ability. • Operationalising musical ability as tuneful singing is a very narrow measure. Someone can have musical ability such as playing an instrument which would not be reflected by this measure. 1 mark for identifying an appropriate reason 2 further marks for elaboration, explanation of why it is a problem, how it might affect the result or for further reason(s). Note that 3 marks can be awarded for one reason elaborated or more than one reason in less detail.
Why might the measure of musical ability used by the teacher lack validity? (3 marks
The main issue is that the teacher has made up her own test: • This involved subjective judgement on the part of the teacher who rates the students' musical ability. Her judgement may not reflect real differences in musical ability and is likely to differ from other people's judgement and/or any absolute criteria for tunefulness. • Lack of reliability in rating musical ability would compromise the validity of the measure. • As the students can choose the song they will sing, the rating of ability could reflect the teacher liking/dislike of the song rather than the student's ability. • The rating may be invalid as the students selected songs which varied in difficulty so the tunefulness reflected the difficulty of the song not the students' ability. • Operationalising musical ability as tuneful singing is a very narrow measure. Someone can have musical ability such as playing an instrument which would not be reflected by this measure. 1 mark for identifying an appropriate reason 2 further marks for elaboration, explanation of why it is a problem, how it might affect the result or for further reason(s). Note that 3 marks can be awarded for one reason elaborated or more than one reason in less detail.
The psychologist asks some of his students to conduct a separate observational study at the same time on the same group of children. The aim of this observational study is to test the idea that eating a healthy breakfast affects playground behaviour. Design an observational study to investigate the effects of a healthy breakfast on playground behaviour. Include in your answer sufficient detail to allow for reasonable replication of the study. You should state the hypothesis you are setting out to test. In your answer, refer to: an appropriate method of investigation materials/apparatus and procedure. Justify your design decisions. (12 marks)
The psychologist asks some of his students to conduct a separate observational study at the same time on the same group of children. The aim of this observational study is to test the idea that eating a healthy breakfast affects behaviour. Design should be written clearly, succinctly and with sufficient detail for reasonable replicability. Candidates will not receive credit for details included in the stimulus material. These include using a random sample of 100 children, gaining parental consent and selection of a Mann Whitney test. To access marks in the top band candidates must state an appropriate hypothesis in which "playground behaviour" is clearly operationalised. The hypothesis could be directional or non-directional. Given the wording of the question, a correlational hypothesis is not credit worthy, however, the rest of the answer should be marked on its merits. Likely aspects of "playground behaviour" would include activity levels, aggression, cooperative play etc. An attempt to operationalise "a healthy breakfast" should be credited. However, candidates could assume this had already been done by the psychologist. As this is an observational study any of the following, together with appropriate justification, would be credit-worthy:- Is the observation covert or overt? Where are observers positioned? (In playground, watching from window?) Is a video recording of the children used? How will this be analysed (eg content analysis)? Do the students who observe know what the children ate for breakfast? At what times of day does the observation take place? How many children are observed? (Candidates could justify using a smaller sub-sample of the 100 children in the original study) How long does each observation last? Will the observers use a behavioural check list/tally chart? Will more than one observer observe each child? If so, what training will be given and what checks for inter-observer reliability will take place? Reference to time sampling or event sampling.
Explain why the teacher chose to use a random sample in this study. (2 marks)
The teacher chose to use a random sample because it would probably be more representative of the whole GCSE group than if she had used an opportunity or volunteer sample. Candidates could also say that she had ready access to her target population making it convenient for her to select a random sample. No credit for definition of a random sample. 1 mark for a brief or muddled reason (it is not biased) 2 marks for a reason that clearly points to an advantage of random sampling. This could be achieved through a comparison with another method (it is less likely to be biased than a volunteer sample)
The psychologist submitted her report on the study for peer review. Discuss the purpose of peer review. - 6 marks
The term 'discuss' implies that students should consider the purpose of peer review and its strengths and/or limitations. In peer review research reports are checked in terms of suitability for publication, appropriateness of the theoretical background, methodology, statistics and conclusions. Definitions of peer review are only creditworthy in so far as they outline the purpose. Discussion is likely to focus on • The work is methodologically sound, valid and does not involve e.g. plagiarism of other people's research • The findings are novel, interesting and relevant, and add to knowledge of a particular research area • The authors are not making unjustified claims about the importance of their findings • Peer review ensures research is reviewed by fellow experts • Peer review maintains the standards of published work and allows University research departments to be rated and funded in terms of their quality; • It helps to ensures that poor quality work is not published in reputable journals • Bias - it has been established that a publication bias occurs towards prestigious researchers and research departments • Bias towards positive findings - negative findings and replications are rarely published, though these can be critical in establishing whether important findings are reliable • Bias in favour of 'established' research areas - novel or unusual research is hard to publish • Time consuming and expensive - peer review can take months, or in some cases where revisions are necessary, years, so delaying publication of important findings • As reviewers are usually working in the same field as the submitted work and competing for limited research funds, there is a temptation to delay or even prevent the publication of competing research • Peer review sometimes fails to prevent scientific fraud Answers that merely outline the purpose of the peer review process can receive a maximum of 2 marks
Describe how the internal validity of the happiness questionnaire could be assessed. (3 marks)
There are a number of ways of assessing the internal validity of the happiness questionnaire. Students can gain credit by explaining one in detail or more than one in less detail: Concurrent validity involves assessing how closely the scores on the happiness questionnaire match a different measurement of happiness obtained from the same participants, for example from family/teacher reports Content validity involves asking experts in the field to check the content of the questionnaire to see how accurately it measures happiness Face validity is less rigorous and involves looking at the questions to see if they are genuinely asking about happiness. Award 1 mark for identifying one or more of these methods and a further two marks for elaboration in relation to the happiness questionnaire.
If the psychologist does find low reliability, what could she do to improve inter-rater reliability before proceeding with the observational research (4)
There is a breadth/depth trade-off here. Candidates can elaborate on one improvement eg explain how the training might be improved or outline several improvements in less detail eg establish clearer criteria for categorising verbal aggression, filming the child so that the observers can practise the categorisation.
Explain how you would record the data from these interviews and your reason for choosing this method. (3 marks)
Three marks are available for a description of how to collect and record the data from the interviews. Possible methods include: • Audio recording • Video recording (filming) • Making written notes during the interview. Award one mark for identifying a method, one mark for explaining why the method would be used and a third mark for elaboration of either. Eg: 'I would choose to audio record the data using my phone (1 mark). This would be less intrusive than filming the patient (1 mark) so they would be more likely to agree to take part or be honest (1 mark).
Explain what is meant by a Type 1 error.
Two marks for explaining the term: where the researcher rejects the null hypothesis (or accepts the research/alternative hypothesis) when in fact the effect is due to chance - often referred to as an error of optimists
(e) The psychologist could have used self-report questionnaires to assess the participants instead of using interviews with the therapist. Explain one advantage and one disadvantage of using self-report questionnaires in this study rather than interviews. (4 marks)
Two marks for the advantage and two marks for the disadvantage. One mark for simply identifying an advantage/disadvantage and the further mark for elaboration in the context of the study. Answers which are not set in context cannot achieve full marks. Advantage: Much quicker to administer and to score - could all have been given out at the same time whereas the therapist has to conduct 30 time-consuming interviews; cheaper than interviews, ie in terms of the therapist's time; people might be more comfortable, and, therefore, more honest, if they have to write responses rather than face an interviewer (could work the other way as well - see disadvantages). Disadvantage: Self-report questionnaires might not yield as accurate data as an interview - questions can limit range of answers and there are no additional cues, eg body language, participants might be less honest on a questionnaire than in a face-to-face interview. Marks can be awarded for any appropriate advantages/disadvantages
In this case, the psychologists decided to use a laboratory experiment rather than a field experiment. Discuss advantages of carrying out this experiment in a laboratory.
Up to four marks are awarded for discussing advantage(s) of using a laboratory experiment in this case. The most likely advantages of the laboratory setting in this experiment include: Control over extraneous variables. The lab setting meant that extraneous variables could be minimised. In this experiment, outside factors such as waiting time, noise and stress (which would be difficult to control in a field experiment) were removed. Ethical issues. In this case, the testing of memory in a field experiment would have involved ethical issues including deception of patients or withholding of information. Candidates may also refer to other advantages of the laboratory setting such as replicability. These can receive full credit if they contextualised within the scenario. Award four marks for an answer which provides accurate and detailed discussion of relevant advantage(s) with a clear link to the scenario. Award two or three marks for an answer which includes discussion of relevant advantage(s), with some reference to the scenario. Award one mark only for an answer which merely identifies one or more relevant advantage(s) of a laboratory experiment appropriate to this scenario. Advantages of laboratory experiments which are not relevant to this study cannot gain any credit eg use of technical equipment.
Identify ethical issues in this follow-up study and explain how the psychologist could deal with them. (4)
mark for identifying one or more ethical issues. 3 further marks for outlining methods of dealing with them, eg • Lack of informed consent: informed consent, obtained through using a consent letter that the participant must sign • Consent letter containing outline details of the study (informed consent) and referring to the right to withdraw and confidentiality of data. • In cases of deception, presumptive consent may be used, and full debriefing would be essential. 2 6 2 7 MARK SCHEME - A-LEVEL PSYCHOLOGY A - PSYA4 - JUNE 2015 33 of 34 • Deception: debriefing, explaining the purpose of the study and why deception was necessary • Deception: presumptive consent, asking non-participants if they would be happy to do the study • Protection from harm eg if participants are categorised as "low empathy" they should be offered counselling. Students may cover one ethical issue in detail (e.g. deception, covering debriefing and presumptive consent) or more than one in less detail
What is meant by the term content analysis?
technique for analysing data according to themes or categories.
Explain one or more ethical issues that the psychologists should have considered in this experiment (4)
• Protection of participants from harm whilst studying the effects of a hands-free phone on driving. Two key issues here are the use of a computer-based test with no risk attached and of an experienced sample of police drivers. • Informed consent: Participants should be given full information about the nature of both tasks before deciding whether or not to participate. • Debriefing: A full debriefing should take place at the end of the experiment. This should provide feedback on performance and allow participants to ask questions if they wish to. • Freedom to withdraw: Participants should be made aware of their freedom to withdraw before and during the experiment. They should be made aware of their right to withdraw their data after the experiment. • Confidentiality: Individuals should not be identified, but should retain anonymity (use of numbers or initials instead of names).
Explain how the psychologists might have carried out content analysis to analyse the film clips of driver behaviour. (4)
• The psychologist could have begun by watching some of the film clips of driver behaviour. • This would enable the psychologist to identify potential categories which emerged from the data of the different types of distractions seen in the film. • Such categories/themes might include: passenger distractions, gadget distractions, etc. • The psychologists would then have watched the films again and counted the number of examples which fell into each category to provide quantitative data.
Explain how the psychologist might have carried out content analysis to analyse these drawings. (3)
• The psychologist would have identified a number of categories or themes by which to sort the drawings. Such categories/themes might include: the type of food depicted eg carbohydrate, protein; the state of the food eg cooked, raw etc; the portion size; the brightness of the colours used. • He would have counted examples from each category to provide quantitative data. • He could then compare the drawings according to these categories to see if there were changes over the 4 week period.
In the discussion section, researchers are also expected to consider any possible applications of their research. Suggest one practical application that might arise from these findings. -2
• to help decide what colour to pick for an educational facility. • To help decide what colour enhances persuasion in a consumption context. • To help decided what colour enhances creativity in a new product design process. 'You could use particular colours for pages in textbooks' = 1 mark ' Red might be used in textbooks covering analytical subjects like maths' = 2 marks
