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    Psychological Research and Scientific Method

    Two psychologists investigated the relationship between age and recall of medical advice. Previous research has shown that recall of medical advice tended to be poorer in older patients. The study was conducted at a doctor’s surgery and involved a sample of thirty patients aged between 18 and 78 years. They all saw the same doctor, who made notes of the advice that she gave during the consultation.

    One of the psychologists interviewed each of the patients individually, immediately after they had seen the doctor. The psychologist asked each patient a set of questions about what the doctor had said about their diagnosis and treatment. The patient’s responses were recorded and then typed out. Working independently, the psychologists compared each typed account with the doctor’s written notes in order to rate the accuracy of the accounts on a scale of 1-10. A high rating indicated that the patient’s recall was very accurate.

    16) The psychologists decided to propose a directional hypothesis. Why was a directional hypothesis appropriate in this case? (1 mark)
    A directional hypothesis was proposed and appropriate because the psychologists expected the correlation to move in a specific direction, e.g., negatively “ as age increased, memory for medical facts decreased’. This proposal was based on prior research in the area.
    17) Write a suitable directional hypothesis for this investigation. (3 marks)
    “ There will be a negative correlation between the age of participants and the number of medical facts they can recall that are given to them by their doctor; the older they are the less facts they will be able to recall.’

    18) The psychologists were careful to consider the issue of reliability during this study. What is meant by reliability? (1 mark)
    Reliability refers to the consistency of a measure. A test or set of data is considered reliable if we get the same result repeatedly.

    19) Explain how psychologists might have assessed the reliability of their ratings (3 marks).
    The psychologists might have assessed the reliability of their ratings by using another psychologist to analyse the ratings. This is known as inter-rater reliability. The ratings of both psychologists should correlate positively so that the researchers can have faith that the ratings are indeed reliable, e.g. consistent repeatedly.

    20) The study collected both qualitative and quantitative data. From the description of the study above, identify the qualitative data and the quantitative data. (2marks).
    The qualitative data was when each patient was asked a set of questions about what the doctor had said about their diagnosis and treatment. This was because the patient’s responses were open ended they could talk freely and were not restricted for example by choosing closed responses from set choices. The patient’s responses were recorded and then typed out. The quantitative data was when patient’s responses were rated for accuracy against the doctor’s notes and given an ordinal scale number. E.g., 10 if the raters thought the patients response mirrored the doctors.

    The psychologists used a Spearman’s rho to analyse the data from their investigation. They chose to use the 0.05 level of significance. The result gave a correlation coefficient of -0.52
    21) Give two reasons why the psychologists used a spearman’s rho to analyse the data. (2 marks)
    Two reasons why the psychologists used a spearman’s rho to analyse the data was they need a test of correlation, the data was ordinal (e.g., rating on a scale can be ordered from highest to lowest but the gaps between the scales are not mathematical as they are down to the opinion of the raters.

    22) Using Table 1 below, state whether the result is significant or nor not significant and explain why. (2marks).
    The critical value for a one tailed hypothesis where p<0.05 and N=30 is 0.306. As the calculated value of rs was -0.52 the null hypothesis can be rejected as it exceeded the critical value. We can therefore conclude that age and recall of medical facts are negatively correlated.

    Table 1: Extract from a table of CRITICAL VALUES of Spearman’s rho (rs)
    LEVEL OF SIGNIFICANCE FOR A ONE TAILED TEST
    0.05 0.01
    LEVEL OF SIGNIFICANCE FOR A TWO TAILED TEST
    0.10 0.02
    N=29 0.312 0.433
    30 0.306 0.425
    31 0.301 0.418
    Calculated rs must exceed the table (critical) value for significance at the level shown.

    23) Explain what is meant by a type 1 error (2 marks).
    A type 1 error is when psychologists accept the experimental hypothesis and reject the null when the reverse is true. This can occur with any significance level chosen but is more likely to occur when a 10% level is chosen. Researchers will not know they have made a type 1 error until they replicate their results or if the calculated value is very close to the standard critical values of 5% and 10% and under the 1% critical value.

    24) Use the information in TABLE 1 above to explain why the psychologists did not think that they had made a type one error in this case. (3marks).
    The psychologists did not think that they had made a type one error in this case because the calculated value exceeded the critical value even at the 1% significance level ( by 0.095 ).

    The psychologists then wanted to see whether the use of diagrams in medical consultations would affect the recall of medical information.

    In a laboratory experiment involving a medical consultation role-play, participants were randomly allocated to one of two conditions. In condition A, a doctor used diagrams to present to each participant a series of facts about high blood pressure. In condition B, the same doctor presented the same series of facts about high blood pressure to each participant but without the use of diagrams.

    At the end of the consultation, participants were tested on their recall of facts about high blood pressure. Each participant was given a score out of ten for the number of facts recalled.

    25) In this case, the psychologists decided to use a laboratory experiment rather than a field experiment. Discuss advantages of carrying out this experiment in the laboratory. (4marks)
    Laboratory experiments are often favoured over field experiments because there is absolute control over variables. In the example above the psychologists could ensure that both group A and group B heard exactly the same information and that this was not confounded by extraneous variables such as receptionist calling during an appointment and interrupting the flow of concentration of patient and/or doctor. Moreover, role-play would ensure that patients were not really stressed by real health problems and that anxiousness did not interfere with their listening skills. Lab experiments are easier to replicate because of this absolute control. Thus cause and effect relationships easier to establish. Obviously internal validity is an issue as participants knew they were in an experiment and may have displayed demand characteristics.
    26) 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. (2marks).
    A Man Whitney U inferential test would be appropriate because a test of difference was needed and the design was independent groups. The level of measurement was interval (e.g., recalling numbers of facts are quantifiable data with mathematical intervals and can be ordered from smallest to largest).

    27) Research has shown that music can affect 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 (e.g., word search).

    You must use a repeated measures design.

    In your answer you should:

    • Fully operationalise the dependent and independent 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. (10 marks)

    Design
    Experiment. Repeated measures design. Independent variable: different types of music. Operationalised as Reggae music (Bob Marley’s One Love non lyric version) and classical music (Mozart’s Requiem). The dependent variable was concentration this was operationised as the number of digits participants could recall from ten sets of seven string number/letter arrays.
    Controls
    • Standardised instructions
    • Same volume of music
    • Number/letter arrays to avoid chunking
    • Two distinct music types were chosen as classical music is said to often improve concentration and memory because of the way it affects brain waives. Therefore a real comparison was needed.
    • That both types of music contained no lyrics so that lyrics did not confound results.
    • Counterbalance groups to avoid order effects

    Participants
    40 males and females aged between 18-20, all math degree students at Orpington University recruited via poster in common room (volunteer sample). Mixed class, ethnicity. No other variables deemed important.
    Researcher: one female aged 43
    Apparatus/materials
    • Standardised instructions
    • Consent form
    • Mark scheme
    • Digital arrays on power point)
    • The music Bob Marley and Mozart
    • Pens and record sheets for arrays
    • DVD player. Volume 7
    • Debrief
    • Poster for advert

    Procedures
    Counterbalance groups by random allocation (drawing names from a hat).
    Two researchers conduct counterbalance groups at the same time independently
    Give participants standardized instructions
    Then consent form (fully informed as hypothesis will be obvious due to design).
    Start music
    Play arrays on powerpoint.
    Participants wait ten seconds and the write the arrays they recall.
    Swap conditions.
    Debrief. Give chance to ask questions. Thank participants.
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    well that has f'd up my chances of an A. Thank you for depressing me xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxnoxxxxx
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    hopefully wasn't too far off
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    (Original post by cherryblossomx)
    well that has f'd up my chances of an A. Thank you for depressing me xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxnoxxxxx
    Tell me about it. Nice one.
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    (Original post by cherryblossomx)
    well that has f'd up my chances of an A. Thank you for depressing me xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx xxxxxxxxxxxxxxxxxxxxxxxnoxxxxx
    Sorry
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    From the passage above differnciate between directional and non directional hypothesis
 
 
 
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