Descriptive statistics & data display

The two researchers compared their data to assess inter-observer reliability. This produced a correlation coefficient of +0.26

Briefly explain what a correlation coefficient of +0.26 means in terms of the reliability of the two researchers’ observations.

The results of the study are given in the table below.

Table 1 Median scores and ranges from the multiple-choice test for the two groups

What do the median and range values in Table 1 suggest? Justify your answer.

A bar chart could be used to display the measures of central tendency shown in Table 1.

Suggest an appropriate label for each axis of the bar chart.

The researcher also tested the motor (movement) skills of the children in Group 1 using a newly devised test.

The measures of central tendency for the motor skills test were as follows: Mean = 20.5, Mode = 30, Median = 25.5

Use the measures of central tendency to identify the type of distribution of scores in the motor skills test. Explain your answer.

Explain how the researcher could modify the motor skills test so that it would be more likely to produce a set of scores that is normally distributed.

The researcher noticed that a lot of the children who did well on the musical ability test also seemed to do well on the motor skills test.

Suggest how the researcher could use the existing data to investigate the relationship between musical ability and motor skills.

The researcher calculated averages for the time (in minutes) spent in the sandpit for each

age group. The results are shown in the table below.

Table 1 Average time in minutes spent in the sandpit for the two age groups

Identify the type of distribution shown in the data in Table 1 for each age group. In each case justify your answer.

What do the mean values in Table 1 suggest about play preferences in 2-year-old and 4-year-old children? Justify your answer.

At the end of the month, the psychologist calculated the median number of ‘social media friends’ for participants in each group. The results are shown in the following table.

Table 2 Median number of ‘social media friends’ for Group 1 and Group 2

What conclusion could the psychologist make from the results in Table 2 ? Justify your answer.

To analyse the results, the psychologist calculated the median sex-role stereotyping score in a questionnaire for participants in each group at the end of the month. A high score in the questionnaire means a participant shows higher sex-role stereotyped attitudes. The results are shown in the following table.

Table 3 Median sex-role stereotyping score in a questionnaire for

What conclusion could the psychologist make from the results in Table 3 ? Justify your answer.

To analyse the results, the psychologist calculated the median conservation score for the participants in each group. The results are shown in the following table.

Table 4 Median conservation scores for Group 1 and Group 2

What conclusion could the psychologist make from the results in Table 4 ? Justify your answer.

The psychologist calculated the median and range of stress ratings after each condition. This data is presented in Table 1.

Table 1 Median and range of stress ratings reported in each experimental condition

What do the median and range values presented in Table 1 suggest about the students’ stress ratings after each condition? Justify your answer.

Explain one limitation of using the range to represent the spread of stress ratings.

The calculated value of r for the Pearson’s test was + 0.42.

Which one of the following scattergrams best represents a correlation coefficient of +0.42?

Shade one box only.

The researcher used the following table of critical values.

Table 1 Critical values of r for Pearson’s test

Calculated value of r must be equal to or more than the critical value for significance to be shown Degrees of freedom (df) = N – 2

Researchers studied therapies for schizophrenia. They assessed the mood of two groups of participants before the participants received therapy. The same participants were assessed again after four weeks of receiving therapy.

Group 1 (Drug therapy group) received drug therapy alone.

Group 2 (Combined therapy group) received a combination of drug therapy and cognitive therapy.

The researchers assessed mood using a standardised test of mood. A low score indicated negative mood and a high score indicated positive mood. Scores ranged from 0 to 100. The lowest score was 24 and the highest score was 83.

Table 1 shows the results of the study after four weeks of therapy.

Table 1 Mean mood scores for Group 1 (Drug therapy group) and Group 2 (Combined therapy group) after four weeks of therapy

Explain why the data in Table 1 does not enable the researchers to draw proper conclusions about the effectiveness of therapy for the two groups. What should the researchers do about this?

Researchers studied psychological support for people on a strict diet. They assessed the mood of two groups of participants before the participants received psychological support. The same participants were assessed again after four weeks of receiving support.

Group 1 (Family support group) received family-based support.

Group 2 (Individual support group) received one-to-one support.

The researchers assessed mood using a standardised test of mood. A low score indicated negative mood and a high score indicated positive mood. Scores ranged from 0 to 100. The lowest score was 24 and the highest score was 83.

Table 2 shows the results of the study after four weeks of receiving support.

Table 2 Mean mood scores for Group 1 (Family support group) and Group 2 (Individual support group) after four weeks of receiving support

Explain why the data in Table 2 does not enable the researchers to draw proper conclusions about the effectiveness of different types of support. What should the researchers do about this?

Researchers studied therapies for stress. They assessed the mood of two groups of participants before the participants received therapy. The same participants were assessed again after four weeks of receiving therapy.

Group 1 (Drug therapy group) received drug therapy alone.

Group 2 (Combined therapy group) received a combination of drug therapy and stress inoculation therapy.

The researchers assessed mood using a standardised test of mood. A low score indicated negative mood and a high score indicated positive mood. Scores ranged from 0 to 100. The lowest score was 24 and the highest score was 83.

Table 3 shows the results of the study after four weeks of therapy.

Table 3 Mean mood scores for Group 1 (Drug therapy group) and Group 2 (Combined therapy group) after four weeks of therapy

Explain why the data in Table 3 does not enable the researchers to draw proper conclusions about the effectiveness of therapy for the two groups. What should the researchers do about this?

Suggest a more appropriate measure of central tendency for this data set and explain why it would be more appropriate.

Which of the following correlation co-efficients best describes the data represented in Figure 2 ?

Shade one circle only.

A –0.80

B –0.25

C +0.25

D +0.80

Identify the type of graph shown in Figure 2 and explain why this is an appropriate graph to use for the data collected.

Explain why it would not be appropriate for the researchers to conclude that increased recreational screen time reduces academic performance.

The results obtained from the experiment are summarised in Table 2.

Table 2 Descriptive statistics for the test performance scores for

Using the data in Table 2, explain how the distribution of scores in Group A differs from the distribution of scores in Group B.

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.

In 1987, a survey of 1000 young people found that 540 said they smoked cigarettes, whilst 460 said they did not. In 2017, a similar survey of another 1000 young people found that 125 said they smoked cigarettes, whilst 875 said they did not.

Calculate the ratio of smokers to non-smokers in 2017. Give your answer in simplest form.

Show your workings.

There was an overall increase in sales of Tiger following the advertisement campaign. Interestingly, the increase in sales was greater for male customers than for female customers. See Table 1 below.

Table 1 Sales figures before and after the Tiger advert

Calculate the percentage increase in sales of Tiger to male customers. Give your answer to two significant figures.

Show your workings.

Design an independent groups experiment that the psychology teacher could conduct.

In your answer you should provide details of:

• the aim of the experiment

• identification and manipulation of variables including details of the task

• controls to minimise the effects of extraneous variables

• data handling and analysis – use of descriptive statistics and/or data presentation.

Justify your design choices.

Each participant had a different total score in the before condition, where the maximum score was 40 and the median score was 23.

How many of the participants had a score < the median in the before condition? Explain your answer.

Each participant had a different total score in the before condition, where the maximum score was 40 and the median score was 23.

How many of the participants had a score < the median in the before condition? Explain your answer.

Each participant had a different total score in the before condition, where the maximum score was 40 and the median score was 23.

How many of the participants had a score < the median in the before condition? Explain your answer.

Draw a suitable graphical display to represent the data in Table 1. Label your graph appropriately.

Estimate the correlation coefficient most likely to result from analysis of the data in Table 1. Shade one box only.

The correlation coefficient would be approximately

Julia decided to record how many hours her baby slept for in the day and in the night for one week.

Table 1 The number of hours slept in the day and the number of hours slept in the night

Calculate the mean number of hours slept in the night. Show your workings.

Give your answer to two significant figures.

Explain one reason why the mean is the most appropriate measure of central tendency for this set of data.

A psychologist was reading an article about typical dream themes in adults.

Figure 2 shows the main dream themes identified in the article.

Figure 2 Main dream themes

Using Figure 2, estimate the percentage of dreams that were reported to be about being chased. Shade one box only.

A 4%

B 12%

C 27%

D 42%

When comparing the data for males and females, the psychologist found that there was a difference in the proportion of friendly and aggressive social interactions. This is shown in Table 2.

Table 2 Percentage of friendly and aggressive social interactions in dreams reported by males and females

A total of 375 dreams reported by males included social interaction. Use the data in Table 2 to calculate how many of these dreams reported by males were classified as aggressive. Show your workings.

Draw a suitable graphical display to represent the data in Table 2. Label your graph appropriately.

The psychologist collated the responses of all the participants over the two-week period and calculated the mean and standard deviation for each condition.

Table 3 Mean number of nightmares reported and the standard deviation for each

What do the mean and standard deviation values in Table 3 suggest about the effect of the type of film watched on the occurrence of nightmares? Justify your answer.

A psychologist investigated cognitive processing in two groups of people with schizophrenia. People in Group A showed positive symptoms of schizophrenia and people in Group B showed negative symptoms of schizophrenia. Each person completed a cognitive task and was given an overall score. The psychologist then calculated average scores for each group. The results are shown in Table 2 below.

Using the data in Table 2, explain how the distribution of scores in Group A differs from the distribution of scores in Group B.

A psychologist investigated perception of foods in two groups of people. People in Group A were on a calorie-counting diet and people in Group B were on a low-fat diet. Each person completed a perception task and was given an overall score. The psychologist then calculated average scores for each group. The results are shown in Table 3 below.

Using the data in Table 3, explain how the distribution of scores in Group A differs from the distribution of scores in Group B.

A psychologist investigated workplace stress in two groups of people. People in Group A were employed by a company and people in Group B were self-employed. Each person completed a stress test and was given an overall score. The psychologist then calculated average scores for each group. The results are shown in Table 4 below.

Using the data in Table 4, explain how the distribution of scores in Group A differs from the distribution of scores in Group B.

The results of the study are given in Table 1 below.

Table 1 Mean number of seconds taken to complete the 400m run and the

Explain why a histogram would not be an appropriate way of displaying the means shown in Table 1.

Name a more appropriate graph to display the means shown in Table 1. Suggest appropriate X (horizontal) and Y (vertical) axis labels for your graph choice.

What do the mean and standard deviation values in Table 1 suggest about the participants’ performances with and without music? Justify your answer.

Calculate the percentage decrease in the mean time it took participants to run 400 metres when listening to music. Show your workings. Give your answer to three significant figures.