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A group of psychiatrists conducted research with patients experiencing depression - AQA - A-Level Psychology - Question 3 - 2017 - Paper 2
Question 3
A group of psychiatrists conducted research with patients experiencing depression. They asked the patients to rate their mood every day over a month, using a scale w... show full transcript
Worked Solution & Example Answer:A group of psychiatrists conducted research with patients experiencing depression - AQA - A-Level Psychology - Question 3 - 2017 - Paper 2
Step 1
Calculate the measures of central tendency for the data in Table 1 and complete Table 1 with your answers.
Answer
To calculate the measures of central tendency:
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Mean Score: To find the mean, sum all the mood scores and divide by the number of patients.
Mean = ( \frac{5 + 6 + 3 + 7 + 4 + 4 + 2 + 7 + 7 + 6}{10} = \frac{ 5 + 6 + 3 + 7 + 4 + 4 + 2 + 7 + 7 + 6}{10} = \frac{ 45}{10} = 4.5 )
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Median Score: To find the median, sort the mood scores in ascending order: 2, 3, 4, 4, 5, 6, 6, 7, 7, 7. Since there are 10 scores (even number), the median is the average of the 5th and 6th scores.
Median = ( \frac{5 + 6}{2} = \frac{11}{2} = 5.5 )
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Mode Score: The mode is the score that appears most frequently. In this case, the mood score of 7 occurs three times.
Mode = 7
Finally, we can complete Table 1 with:
- Mean score: 4.5
- Median score: 5.5
- Mode score: 7.
Step 2
Define what is meant by the term ‘a measure of dispersion’.
Answer
A measure of dispersion refers to a statistical term that describes the extent to which data points in a set differ from each other or from their average value. It indicates the spread or variability of the dataset.
Common measures of dispersion include:
- Range: The difference between the maximum and minimum values.
- Variance: The average of the squared differences from the mean.
- Standard Deviation: The square root of the variance, representing the average distance of each data point from the mean.
Understanding the measures of dispersion helps to evaluate how much variation exists in the data, which is crucial in analyzing the reliability and consistency of the results.
Step 3
Interpret what the two standard deviations tell us about the results.
Answer
The standard deviation is a critical measure in understanding the variability of the mood scores of both groups of patients.
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Standard Deviation of Patients with Depression (1.43): This relatively low standard deviation indicates that the mood scores of patients with depression are closely clustered around the mean. This implies that their mood ratings do not vary significantly from one another, pointing to a more uniform experience of depression among this group.
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Standard Deviation of Patients without Depression (3.46): This higher standard deviation indicates a wider spread in the mood scores of patients without depression. These participants likely experienced a greater variability in their mood ratings, suggesting a diverse range of feelings among individuals in this group.
Conclusion: The contrasting standard deviations highlight the difference in mood variability between the two groups, where patients without depression showcase a broader emotional spectrum, while those with depression exhibit more consistent mood ratings.