EnglandPsychologySyllabus dot point

How do psychologists analyse and present the data they collect?

Data analysis: types of data, measures of central tendency (mean, median, mode) and the range, percentages, ratios and fractions, and ways of displaying data such as bar charts and tables.

A focused answer to Edexcel GCSE Psychology Topic 11, covering data analysis: types of data, measures of central tendency, the range, percentages, ratios and fractions, and displaying data.

Generated by Claude Opus 4.811 min answerUpdated 2026-06-02

Reviewed by: AI editorial process; not yet individually human-reviewed

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What this dot point is asking
Types of data and central tendency
The range, percentages and ratios
Displaying data
Try this

What this dot point is asking

Edexcel wants you to analyse and present data: know the types of data, calculate the measures of central tendency (mean, median, mode) and the range, work with percentages, ratios and fractions, and choose ways of displaying data. This is the maths of psychology, and at least 10 percent of the marks across the course are quantitative, so the calculations must be accurate.

Types of data and central tendency

The three measures of central tendency are:

Mean: the arithmetic average. Add all the scores and divide by the number of scores. For scores $4, 6, 8$ , the mean is $\frac{4+6+8}{3} = \frac{18}{3} = 6$ . It uses every value but is distorted by extreme scores (outliers).
Median: the middle value when the scores are placed in order. For $3, 5, 9$ , the median is $5$ . With an even number of scores, it is the mean of the two middle values. It is not affected by outliers.
Mode: the most frequent value. For $2, 4, 4, 7$ , the mode is $4$ . It is the only measure usable for categories, but a data set can have more than one mode or none.

The range, percentages and ratios

Key fact

The range measures the spread of data: $\text{range} = \text{largest value} - \text{smallest value}$ . For scores $5, 8, 12$ , the range is $12 - 5 = 7$ . A larger range means more spread-out (variable) data.

A percentage expresses a part out of 100: $\text{percentage} = \frac{\text{part}}{\text{whole}} \times 100$ . For example, if $15$ of $50$ participants pass, that is $\frac{15}{50} \times 100 = 30\%$ .

A ratio compares two quantities and is simplified by dividing both sides by their highest common factor. If $20$ chose A and $30$ chose B, the ratio is $20 : 30$ , which simplifies to $2 : 3$ .

A fraction expresses a part of a whole; $15$ of $50$ is the fraction $\frac{15}{50} = \frac{3}{10}$ .

These skills appear in source and data-response questions, where you read values from a table or graph and calculate. Always show your working and give the correct units.

Displaying data

Data is presented in a way that suits its type. A table shows raw or summarised values precisely. A bar chart suits data in separate categories (with gaps between the bars, because the categories are discrete), for example comparing mean scores between two groups. Choosing the right display makes the pattern clear and is itself examinable.

Worked calculation: comparing two groups

A study compares words recalled. Group A scores $6, 8, 7, 9, 10$ ; Group B scores $3, 4, 4, 5, 24$ . Find the mean of each group, the range of Group B, and decide which average best represents Group B. [4 marks]

Step 1: find the mean of Group A

Sum is $6+8+7+9+10 = 40$ ; there are 5 scores, so the mean is $\frac{40}{5} = 8$ words.

Step 2: find the mean of Group B

Sum is $3+4+4+5+24 = 40$ ; there are 5 scores, so the mean is $\frac{40}{5} = 8$ words.

Step 3: find the range of Group B

The largest is $24$ and the smallest is $3$ , so the range is $24 - 3 = 21$ words, a very wide spread.

Step 4: choose the better average for Group B

The score $24$ is an outlier that pulls the mean up, so a mean of $8$ is not typical of most of Group B. The median (ordered: $3, 4, 4, 5, 24$ ) is the middle value, $4$ words, which better represents the group because it is not distorted by the outlier. Markers reward both means, the range, identifying the outlier, and justifying the median.

Try this

Q1. Find the mode of these scores: $3, 5, 5, 8, 5, 2$ . [1 mark]

Cue. $5$ (it appears most often).

Q2. Calculate the range of: $4, 11, 7, 2, 9$ . [1 mark]

Cue. $11 - 2 = 9$ .

Q3. Express $12$ out of $48$ as a percentage. Show your working. [2 marks]

Cue. $\frac{12}{48} \times 100 = 25\%$ .

Exam-style practice questions

Practice questions written in the style of Pearson Edexcel exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.

Edexcel 20194 marksA psychologist records the number of words recalled by six participants: 7, 9, 5, 9, 12, 6. Calculate the mean and the range. Show your working. (Paper 2)

Show worked answer →

This is a quantitative item; markers reward correct working as well as the final values.

Mean: add the scores and divide by how many there are. The sum is $7+9+5+9+12+6 = 48$ , and there are 6 scores, so the mean is $\frac{48}{6} = 8$ words.

Range: subtract the smallest score from the largest. The largest is $12$ and the smallest is $5$ , so the range is $12 - 5 = 7$ words.

Markers reward the correct mean with working (sum then divide) and the correct range (largest minus smallest), each with the calculation shown. A common error is forgetting to show the sum or miscounting the number of scores.

Edexcel 20224 marksIn a study, 18 of 60 participants chose option A. Express this as a percentage and as a ratio of those who chose A to those who did not. (Paper 2)

Show worked answer →

This item tests percentages and ratios; markers reward correct working and simplification.

Percentage: divide the number choosing A by the total and multiply by 100, so $\frac{18}{60} \times 100 = 30\%$ chose option A.

Ratio: 18 chose A and $60 - 18 = 42$ did not, giving a ratio of $18 : 42$ . Dividing both sides by 6 simplifies this to $3 : 7$ (those who chose A to those who did not).

Markers reward the percentage ( $30\%$ ) with working and the ratio simplified to $3 : 7$ . A common error is leaving the ratio unsimplified or comparing A to the total rather than to those who did not choose A.

Related dot points

Sources & how we know this

Pearson Edexcel GCSE (9-1) Psychology (1PS0) specification — Pearson Edexcel (2017)