What are key features in IELTS Writing Task 1?
"Key features" is not a teacher's phrase: it is the wording of the Task Achievement descriptors for Academic Task 1. A key feature is something about the data that a reader must know to understand it: who is biggest or smallest, what changed most, and what behaves differently from the rest. A single figure such as "21% in 2005" is usually not a key feature. It is a detail you may use to illustrate one.
Task Achievement, Academic Task 1: what the descriptors say about key features
| Band | Selecting key features | Overview and detail |
|---|---|---|
| 8 | "Key features are skilfully selected, and clearly presented, highlighted and illustrated." | Not described separately: the features themselves are illustrated. |
| 7 | "Key features which are selected are covered and clearly highlighted", though they could be more fully illustrated | "presents a clear overview"; "main trends or differences are identified" |
| 6 | "Key features which are selected are covered and adequately highlighted." | "A relevant overview is attempted."; information is "supported using figures/data" |
| 5 | "Key features which are selected are not adequately covered." | "The recounting of detail is mainly mechanical." |
| 4 | "Few key features have been selected." | Features presented "may be irrelevant, repetitive, inaccurate or inappropriate" |
IELTS Writing Band Descriptors, Task 1, Task Achievement (ielts.org, updated May 2023), PDF pages 3–5.
Read the table from the bottom up. At band 4, few features are chosen. At band 5, detail is recounted mechanically, and the descriptor warns of "a tendency to focus on details (without referring to the bigger picture)". From band 6, an overview appears, and at band 7 it must be clear, with main trends or differences identified. Selection is the skill being marked, so describing everything is not a safe option: it is the band 5 habit. Full wording: Task 1 Academic band descriptors.
How to identify key features: three questions
Before you write a word, spend two minutes asking the chart three questions. This is BandLadder advice, not an official procedure, but each question maps onto the descriptor wording: extremes and changes are the "main trends or differences", and the exception is what makes your selection skilful rather than automatic.
BandLadder method: three questions, then group
- 1
Extremes. What is highest and lowest? Check the start and the end separately: the leader at the start is often not the leader at the end.
- 2
Biggest change. What moved most, up or down? On a line graph, compare first and last values; on a bar chart, compare the pairs of bars.
- 3
Exception. What breaks the pattern? A category that stays flat while others move, moves the opposite way, or overtakes another.
- 4
Group. Put categories that behave alike together (all rising, all falling). Each group becomes one body paragraph.
The answers to the three questions, without detailed figures, are your overview. The same answers, with the figures that prove them, are your body paragraphs. Everything the questions did not pick up is a minor detail: mention it only if you have room and it supports a feature you have already named.
Key features example: a line graph
Invented data for practice. Each year adds up to 100%.
The three questions applied
| Question | What the chart shows | Where it goes |
|---|---|---|
| Extremes | Gas leads in 2000 (62%); heat pumps lead in 2025 (41%); oil or wood is lowest in 2025 (9%) | Overview (who leads), body (figures) |
| Biggest change | Heat pumps up 39 points, gas down 32: they swap places between 2020 and 2025 | Overview |
| Exception | Electric heaters stay at 20–22% while everything else moves | Overview (one clause), body |
| Group | Falling: gas, oil or wood. Rising: heat pumps. Flat: electric heaters | Body paragraph plan |
In 2000,list 62% of homes used gas, 20% used electric heaters, 2% used heat pumps and 16% used oil or wood. In 2005,list gas was 60%, electric heaters were 21%, heat pumps were 3% and oil or wood was 16%. In 2010,list gas was 55%, electric heaters were 22%, heat pumps were 6% and oil or wood was 17%.
- → Nearly sixty words, only three of the six years covered, and yet no key feature is named: the reader still does not know that heat pumps overtook gas.
- → This is the band 5 pattern: detail recounted mechanically, with no reference to the bigger picture.
Overall, gas heating declined steadily over the periodchange, while heat pumps rose from almost nothing to become the most common type by 2025change + extreme. Electric heaters, by contrast, hardly changed.exception In 2000, gas heated 62% of homes, far more than any other typeextreme, but its share fell in every five-year period, ending at 30%end point. Heat pumps moved the other way: from just 2% in 2000, they climbed slowly at first and then rapidly after 2010, reaching 41% in 2025 and overtaking gas in the final five yearscrossover.
- → The overview names three features and uses no detailed figures. A reader who stops after two sentences already knows the story.
- → The body proves the two biggest changes with start and end figures, and adds one detail (the speed-up after 2010) because it explains the crossover.
- → A second body paragraph would cover the group left: oil or wood (between 15% and 18% until 2020, then down to 9%) and electric heaters (20–22% throughout).
Key features example: a bar chart
Invented data for practice.
Ask the same three questions. Extremes: meeting friends was the top activity in 2015 (9 hours), streaming in 2025 (13 hours); reading was lowest in 2025 (3 hours). Biggest change: streaming rose by 5 hours, and gaming more than doubled. Exception: sport did not change at all. The grouping falls out of the answers: screen activities rose, offline activities fell, sport stood still. That grouping is what the band 7 descriptor calls data that are "appropriately categorised".
Overall, adults spent more time on screen-based activities and less on reading and meeting friendsgroups, so streaming replaced meeting friends as the most time-consuming pastimeextremes. Time spent on sport did not change.exception Streaming rose from 8 to 13 hours a week, the largest increase of any activitybiggest change, and gaming more than doubled, from 3 to 7 hours. In contrast, time spent meeting friends fell from 9 hours, the highest figure in 2015, to 6, and reading dropped from 5 to 3 hours, making it the least common activity in 2025extreme. Sport stayed at 4 hours in both years.
- → Screen-based is a category the writer created. Naming the groups is what turns ten bars into two clear ideas.
- → Every figure in the body proves a feature already named in the overview. No figure is there just because it was on the chart.
The same questions work for tables and pie charts. Maps and process diagrams need a slightly different lens (the biggest change on a map, the start, end and number of stages in a process), but the principle is identical: name what matters, then prove it. For more charts to practise on, browse the line graph tasks and Task 1 samples.
Task 1 key feature mistakes that cost marks
✗ The graph has years on the horizontal axis and percentages on the vertical axis.
✓ Gas heating declined steadily, while heat pumps rose to become the most common type.
Axes and legends are how the chart is drawn, not features of the data. They take words and name nothing.
✗ Heat pumps rose because people became more worried about the environment.
✓ Heat pumps rose from 2% of homes in 2000 to 41% in 2025.
The cause is not in the chart. ielts.org says everything you need is given in the visual, so an invented reason is irrelevant or inaccurate information.
✗ Electric heating increased significantly between 2000 and 2010.
✓ Electric heating barely moved, staying between 20% and 22%.
A two-point change is not significant. Overstating a small change misreports the data and hides the real exception.
✗ In conclusion, the graph shows some interesting changes in heating.
✓ Overall, heat pumps replaced gas as the main heating type, while electric heating hardly changed.
A vague closing line names no feature. The band 7 descriptor asks for "a clear overview" with main trends identified.
Clear grouping also helps your Coherence and Cohesion score, because each body paragraph then has one central topic. The coherence and cohesion sheet shows how to link those paragraphs without a linker on every sentence. When you practise Task 1 on BandLadder, BandLadder AI scores Task Achievement as its own criterion and checks your figures against the chart.
Your turn: pick the key features
Share of a region's electricity from five sources, 2010 and 2024 (%)
| Source | 2010 | 2024 |
|---|---|---|
| Coal | 48 | 12 |
| Gas | 30 | 28 |
| Wind | 6 | 28 |
| Solar | 1 | 13 |
| Hydro | 15 | 19 |
Invented data for practice. Each year adds up to 100%.
Use the table above. Answer each question, then reveal the answer.
- Biggest change: which source moved most?
- A. Coal fell by 36 points
- B. Wind rose by 22 points
- C. Solar rose by 12 points
Show answer
Coal fell by 36 points
48 to 12 is a 36-point fall, larger than any rise in the table.
- Extremes: which source was largest in 2024?
- A. Coal
- B. Gas alone
- C. Gas and wind, equal at 28%
Show answer
Gas and wind, equal at 28%
Both supplied 28% in 2024, more than any other source. Coal, the 2010 leader, had become the smallest.
- Exception: most sources moved a lot. Which one hardly changed?
- A. Gas
- B. Hydro
- C. Solar
Show answer
Gas
Gas moved only 2 points (30 to 28). Hydro moved 4 and solar 12.
- Which comparison is accurate?
- A. Wind overtook coal
- B. Solar overtook hydro
- C. Gas overtook wind
Show answer
Wind overtook coal
Wind was behind coal in 2010 (6 vs 48) and ahead in 2024 (28 vs 12). Solar stayed below hydro, and gas was never behind wind.
- Which sentence belongs in the overview?
- A. Hydro supplied 15% of electricity in 2010.
- B. Coal went from the largest source to the smallest, while wind and solar grew sharply.
- C. The government closed coal plants to reduce pollution.
Show answer
Coal went from the largest source to the smallest, while wind and solar grew sharply.
It names the main change and the extremes without detailed figures. The first is a minor detail; the third is not in the data.
BandLadder questions
Practise it now
Use the method on original BandLadder questions. Attempt them free and see your score.
Questions
FAQ
What are key features in IELTS Writing Task 1?+
They are the points a reader must know to understand the visual: the highest and lowest values, the biggest changes or differences, and anything that breaks the pattern. The Academic Task 1 descriptors use the phrase at every band from 4 to 8.
How do I identify key features in Task 1?+
BandLadder advice: ask three questions. What is highest and lowest at the start and at the end? What changed most? What behaves differently from the rest? Then group categories that behave alike.
How many key features should I include in IELTS Writing Task 1?+
The descriptors set no number. An overview usually needs two or three features, and each one should be illustrated with figures in the body paragraphs.
Do I have to describe every number in Task 1?+
No. ielts.org says you must include the most important points and that some minor points or details may be left out. Reporting every figure in order is the mechanical recounting the band 5 descriptor describes.
Should the Task 1 overview include numbers?+
BandLadder advice: keep detailed figures out of the overview and use them in the body. The overview states the main trends or differences; the body proves them with data.
How many words and how much time for IELTS Writing Task 1?+
At least 150 words in about 20 minutes. Task 2 contributes twice as much to your Writing score, so do not spend Task 2 time describing minor details.
Sources
- IELTS Writing Band Descriptors, Task 1, Task Achievement (ielts.org, updated May 2023): PDF pages 3–5 (key features and overview wording, bands 4–8; irrelevant or inaccurate information, bands 5–6, page 4)
- IELTS Academic: Writing test format (ielts.org): https://ielts.org/take-a-test/test-types/ielts-academic-test/ielts-academic-format-writing
IELTS is a registered trademark of the University of Cambridge, the British Council and IDP Education Australia. PTE is a trademark of Pearson. BandLadder is not affiliated with either.
© 2026 BandLadder. Written and checked by the BandLadder team. You may quote or cite this page with credit to BandLadder and a link to it; republishing it in full needs our written permission. Content use policy