EXAM QUESTIONS Flashcards
Explain why the researcher decided to use the 5% level of significance rather than the
1% level in this study. [2 marks]
The 5% significance level is the conventional level of probability used by psychologists which balances the risks of making a Type I and Type II error.
Explain what is meant by a Type II error in this study [2 marks]
FALSE NEGATIVE
When researcher is STRINGENT believed the findings are not significant and accepted the null hypothesis, and rejected the alternative hypothesis (STATE THE HYPOTHESIS HERE). when they should have accepted the alternative.
False negative = psychologist thinks their findings were not statistically significant, but they were.
Explain what is meant by a Type I error in this study [2 marks]
FALSE POSITIVE
Researcher is LENIENT and believes results are statistically significant and rejects the null hypothesis, and the alternative hypothesis (state it - contextualise) is accepted, when it should actually be rejected because it is not significant.
False positive = psychologist falsely claims their findings are significant when in fact there is no difference/relationship present.
A researcher placed an advert in a university psychology department asking for third year students to participate in a sleep experiment.
Each student had a sleep tracker watch to wear at home for the two-week study. Each morning they were asked to open the sleep tracker app to view their sleep quality data on their mobile phones. The students were unaware that the sleep data they could see on their phones had been manipulated by the researcher. Over the two weeks of the study, each student saw that he or she had had poor sleep quality for seven random nights of the experiment and good sleep quality for the remaining nights.
Every morning, after viewing the sleep data, each student completed a questionnaire about the previous night’s sleep. One of the questions asked the students to rate how well rested they felt, on a scale from 1–10, after the previous night’s sleep. Apart from this, students were asked to continue their normal everyday activities.
a) Write a directional hypothesis the researcher might use for this study. [3 marks]
Students will give a higher rating of how well rested they felt when they saw good sleep data rather than poor sleep data.
OR
Students will give a lower rating of how well rested they felt when they saw poor sleep data rather than good sleep data.
Include “er” to show comparative language.
A researcher placed an advert in a university psychology department asking for third year students to participate in a sleep experiment.
Each student had a sleep tracker watch to wear at home for the two-week study. Each
morning they were asked to open the sleep tracker app to view their sleep quality data on their mobile phones. The students were unaware that the sleep data they could see on their phones had been manipulated by the researcher. Over the two weeks of the study, each student saw that he or she had had poor sleep quality for seven random nights of the experiment and good sleep quality for the remaining nights.
Every morning, after viewing the sleep data, each student completed a questionnaire
about the previous night’s sleep. One of the questions asked the students to rate how well rested they felt, on a scale from 1–10, after the previous night’s sleep. Apart from this, students were asked to continue their normal everyday activities.
b) The researcher collected quantitative data about how well rested the students felt. Explain one strength of collecting quantitative data in this study. [2 marks]
Sleep quality may be interpreted differently by each student and so it may be SUBJECTIVE. [1]
A rating of 3, for example, might mean something different for different students. [1]
Students are not able to explain their rating. [1]
A researcher placed an advert in a university psychology department asking for third year students to participate in a sleep experiment.
Each student had a sleep tracker watch to wear at home for the two-week study. Each
morning they were asked to open the sleep tracker app to view their sleep quality data on their mobile phones. The students were unaware that the sleep data they could see on their phones had been manipulated by the researcher. Over the two weeks of the study, each student saw that he or she had had poor sleep quality for seven random nights of the experiment and good sleep quality for the remaining nights.
Every morning, after viewing the sleep data, each student completed a questionnaire
about the previous night’s sleep. One of the questions asked the students to rate how well rested they felt, on a scale from 1–10, after the previous night’s sleep. Apart from this, students were asked to continue their normal everyday activities.
c) One ethical issue in this study is deception, as the students were unaware that the sleep data they could see on their phones had been manipulated by the researcher.
Explain one way in which the researcher might deal with the deception in this study [2 marks]
At the end of the study students should be given a FULL DEBRIEF where they are made aware that the sleep data provided was manipulated (true aims / deception) [1]
They should then be given the right to WITHDRAW their data if they would like to. [1]
Apart from the question about how well rested the students felt, the researcher’s
questionnaire contained nine other questions. The responses to these questions were not analysed.
Explain one reason why the researcher decided to include these additional questions on
the questionnaire. [2 marks]
Additional questions DISTRACT the students from realising that the focus of the study was on their perceived quality of sleep on a rating scale 1-10 (STATE TRUE AIMS)
OR
Students would be less likely to alter their ratings about their sleep quality, reducing demand characteristics (improving internal validity).
In a follow-up study, the researcher investigated whether there was a correlation between the number of hours slept and how well rested the students felt.
The researcher randomly selected 18 participants from first-year students at the university.
On the day of the study, each student participant was asked, ‘How many hours did you
sleep last night?’ They then had to rate on a scale of 1 to 5 how well rested they felt.
The researcher hypothesised that there would be a positive correlation between the two co-variables.
Outline one reason why it was appropriate to conduct a correlation rather than an
experiment in this case. [2 marks]
It would be difficult to dictate the number of hours the students should sleep.
It may be more ETHICAL to conduct a correlation rather than restrict how many hours each student slept.
Suggest why it would be appropriate to conduct a correlation rather than an experiment. [2 marks]
It is more PRACTICAL.
It is more ETHICAL.
It would be impractical and unethical conducting an experiment if it means pps are sleep deprived for e.g.
The researcher believed that the actual number of hours slept by the students could have affected the results of the study.
Suggest one other extraneous variable that could have affected the results of this study.
Explain why it would have been important to control this extraneous variable and how it
could have been controlled in this study. [4 marks]
A* QUESTION
Consumption of alcohol/caffeine prior to sleep – this may make students feel worse in the morning making them give a lower rating regardless of the sleep tracker data (decreasing validity).
Control =
tell students not to consume any stimulants/depressants in the evenings of the study.
(scattergram is shown with a negative correlation)
Explain why it would not be appropriate for the researchers to conclude that increased
recreational screen time reduces academic performance. [2 marks]
Third variable could be responsible for the relationship, eg personality type, number of hours spent studying. [2]
OR
Correlation only shows a relationship between the two co-variables, recreational screen time and academic performance.
OR
Researcher’s conclusion implies causation, increased recreational screen time impairs academic performance
The results obtained from the experiment are summarised in Table 2.
Table 2 Descriptive statistics for the test performance scores for Group A and Group B:
Group A Group B
(no screen time) (unrestricted screen time)
Mean 73.6 66.3
Median 74.0 58.0
Mode 74.0 44.0
Standard deviation 13.2 25.1
Using the data in Table 2, explain how the distribution of scores in Group A differs from the distribution of scores in Group B. [4 marks]
The data in Group A is symmetrical/normally distributed… [1]
… because the mean (73.6) is approximately equal to the mode/median (74) [1]
The data in Group B is positively skewed… [1]
…because the mean (66.3) is greater than the mode (44)/median (58). [1]
The results obtained from the experiment are summarised in Table 2.
Table 2 Descriptive statistics for the test performance scores for Group A and Group B:
Group A Group B
(no screen time) (unrestricted screen time)
Mean 73.6 66.3
Median 74.0 58.0
Mode 74.0 44.0
Standard deviation 13.2 25.1
What do the mean and standard deviation values in Table 2 suggest about the effect of the recreational screen time on test performance? Justify your answer. [4 marks]
Suggestion 1 =
recreational screen time has a negative impact on test performance. [1]
Justification 1 =
mean test performance is higher when there is no recreational screen time
(Group A) than when recreational screen time is unrestricted (Group B). [1]
Suggestion 2 =
the impact of recreational screen time on test performance is not consistent [1]
Justification 2 =
there was a wider variation of test performances/higher standard deviation in
Group B compared to Group A. [1]
One criticism of the study is that the pupils were not matched on their typical recreational screen time.
Explain how the psychologist could have matched pupils on their typical recreational
screen time across the experimental conditions. [4 marks]
Psychologist could use a baseline questionnaire or interview parents to report/pupils self-report their average daily recreational screen time. [1]
For example, a question could be “On average, how many hours per day do you spend on recreational screen time such as a phone or TV?” [1]
Pupils with similar recreational screen time use would be paired. [1]
One pupil from each pair would be (randomly) placed in Group A and the other in Group B. [1]
The psychologist decided to design an experiment to test the effects of recreational screen time on children’s academic performance.
The psychologist randomly selected four schools from all the primary schools in her county to take part in the experiment involving Year 5 pupils. Three of the four schools agreed to take part. In total, there were 58 pupils whose parents consented for them to participate. The 58 pupils were then randomly allocated to Group A or Group B.
For the two-week period of the experiment, pupils in Group A had no recreational screen time. Pupils in Group B were allowed unrestricted recreational screen time. At the end of the experiment all pupils completed a 45-minute class test, to achieve a test score.
The psychologist wanted to test the statistical significance of the data.
Identify the most appropriate choice of statistical test for analysing the data collected and explain three reasons for your choice in the context of this study. [7 marks]
Mann-Whitney test [1]
It is testing for a difference – having no recreational screen time on exam performance as opposed to having unlimited recreational screen time. [2]
Uses an independent/unrelated design – the pupils either had no recreational screen time or unlimited recreational screen time - not related. [2]
Data is ordinal – the difference between each test score is not fixed - scores could be ranked. [2]
For each of the following bullet points award either:
> 2 marks for a clear and coherent reason linked to the study.
1 mark for a limited/partial reason.
