Data commentary is writing about information shown in a table, graph, or chart. You may need to write about your own data or data from other sources.

 

Describing and interpreting

Effective data commentary includes both description and interpretation. Description states what the data shows. Interpretation explains what it might mean and why it is important. For example:

 

'Patient satisfaction increased from 70% to 85% between January and June. This suggests that patients were happier with the service after the changes were made.'

 

The first sentence describes the data. The second interprets it.

Strong data commentary helps you to explain patterns clearly, support the argument you are building with evidence, and show critical thinking. These are things that markers focus on when awarding higher grades.

 

 

Understanding and interpreting data

Describing data

When you look at a table or graph, first focus on what you can see:

  • What is the range of values (highest and the lowest)?
  • Are there trends (increase, decrease, or no change)?
  • Are there clusters (groups of similar values)?
  • Are there any anomalies (results that do not fit the pattern)?
  • What exactly is being shown (people, objects, or events), and what units are used? 

 

Interpreting data

After describing the data, move to explaining what it might mean:

  • Why might the data look like this?
  • Where does the data come from geographically? Might it be different elsewhere?
  • When was the data collected? Is it up to date for your purpose?
  • Who produced the data (researcher or organisation), and could this affect how it is presented?
  • So what does this mean overall? (How does this support your argument?)

 

 

Structuring your data commentary

A data commentary typically follows this order:

  1. Introduce the general subject of the data, the main trend, and the range of values (the highest and the lowest).
  2. Discuss trends (patterns of change) and clusters (groups of similar values) and compare key features.
  3. Address anomalies that do not fit the pattern.
  4. Compare the data with similar research to help explain those anomalies.
  5. Explain what the data suggest. Support this with references to existing research.

 

 

Using tables and figures in your writing

Include only figures, tables, and charts that are directly relevant to your study. You don't need to include raw data in the main body of your work. Raw data means unprocessed numbers or full data tables.

Tables and figures should have a clear title or legend that explains what they show. The legend should help the reader understand the data without reading the full text. Our Library guidance covers labelling figures and tables using the APA style and using the Vancouver style.

All figures and tables included in the main body of your assignment should be referred to at least once in your writing.

 

When you refer to a table or graph, follow these three steps:

  1. Identify where the data appears (which figure or table)
  2. Summarise what it shows
  3. Explain what it means for your assignment

Example

Figure 2 shows the percentage of respondents by age group.1 The largest group is 18- to 24-year-olds, who represent 43% of responses.2 This suggests that younger adults are more interested in this topic than older age groups.3

 

Key

  1. Identify where the data appears (which figure or table) Back to text, note 1
  2. Summarise what it shows Back to text, note 2
  3. Explain what it means for your assignment Back to text, note 3

Example

Table 1 shows unemployment rates across five European countries between 2018 and 2022.1 Rates rose sharply in all countries between 2019 and 2020.2 This increase reflects the impact of the COVID-19 pandemic (Eurostat, 2021).3

 

Key

  1. Identify where the data appears (which figure or table) Back to text, note 1
  2. Summarise what it shows Back to text, note 2
  3. Explain what it means for your assignment Back to text, note 3

 

Reference

Eurostat. (2021). Unemployment rate rose in the majority of EU regions in 2020. European Commission. https://ec.europa.eu/eurostat/web/products-eurostat-news/-/ddn-20210428-1

 

The referencing style used here is APA 7. Your course may require a different referencing system. Check your assignment brief or module guidance to confirm which style applies to you.

 

 

Page last edited: 25 August 2026
Next review due: 20 July 2029