What are the most common mistakes in IELTS Academic Writing Task 1?
Across 201 IELTS Academic Writing Task 1 reports analysed by IELTS Writing Checker, describing the data accurately and completely is the most common problem at every score level, appearing as a must-fix error in 81% of reports at band 5.5 and below, 79% of reports at bands 6 to 6.5, and 46% of reports at band 7 and above. By contrast, must-fix overview problems appear in 36% of reports at 5.5 and below and 23% at bands 6 to 6.5, and drop to 0% in reports scored at 7 and above.
Imagine a learner whose Task 1 score stays stuck at 6 or 6.5 despite practising chart vocabulary and sentence structures. In our dataset, at bands 6 to 6.5 the single most common must-fix problem was getting the data itself wrong, affecting 79% of reports. Before vocabulary or sentence variety can lift a report into the higher bands, the figures, categories, and trends on the page have to match the chart.
To see where Task 1 marks differ across levels, we grouped the 201 reports by their overall estimated score into three tiers—band 5.5 and below (42 reports), bands 6 to 6.5 (62 reports), and band 7 and above (97 reports)—and tracked both their scores on the four IELTS Writing criteria and the must-fix errors marked in our sentence-level corrections. Figure 1 shows the two task-specific problems side by side: data description remains a challenge even at 7 and above, whereas overview problems divide the middle bands from the top tier.
How do data-reporting errors change from band 5.5 to 7 and above?
Because nearly four out of five reports below band 7—and nearly half of reports at band 7 and above—contain at least one must-fix data-description error, we broke those errors down into specific categories to see what goes wrong when learners describe a chart, graph, table, map, or diagram.
As Figure 2 shows, misreading or reporting a wrong value or detail from the visual is the most frequent data problem overall, and clearly the most common at bands 6 to 6.5 (55% of reports) and at band 7 and above (31%); at band 5.5 and below, wrong values or details (40%) and leaving out a key category or detail (36%) are similarly common. Across the dataset, writers quote the wrong figure from a chart, swap compass directions on a map, miscount the length of a time period, or misstate the number of categories. In our sentence-level corrections, we saw slips across all three score groups: "the exhibition rooms in the west have remained unchanged" → "...in the east..." (bands 6–6.5), "this 9-year period" → "this 10-year period" (bands 6–6.5), "China, at 8%, was slightly higher than that for the world, at 7%" → "China, at 9%, ... the world, at 8%" (band 7 and above), and "other four categories" → "the other six categories" (band 5.5 and below).
Leaving out a key category or detail is the second most common data mistake overall, appearing in 36% of reports at 5.5 and below, 27% at bands 6 to 6.5, and 16% at band 7 and above. If a chart compares several categories or a process diagram shows multiple stages, skipping a key feature leaves the summary incomplete, which the Task Achievement criterion penalises. Writers in all three groups also occasionally describe a trend wrongly.
Two other habits largely disappear in reports at band 7 and above. Missing or wrong units appear in 12% of reports at 5.5 and below and 13% at bands 6 to 6.5, but in only 1% of reports at band 7 and above. Some writers below band 7 overlook the axis scale—writing "at 850 and 650" → "at 850,000 and 650,000" when the axis is in thousands (band 5.5 and below)—or confuse percentages with percentage points, such as writing "33% higher" → "33 percentage points higher" (bands 6–6.5). Similarly, adding an explanation or cause not shown in the visual appears in 7% of reports at 5.5 and below and 6% at bands 6 to 6.5, compared with 0% at band 7 and above.
Spending the first two minutes reading the title, axis labels, units, and every category before writing is a practical fix for Task 1. Ticking off each category on the question paper helps ensure nothing is left out, and checking the scale prevents unit mistakes.
Why does the overview separate band 6.5 from band 7 and above?
While data slips still occur in 46% of reports at band 7 and above, none of the 97 reports at 7 and above had a must-fix overview problem.
Very few writers simply leave the overview out: a missing or unfinished overview was flagged as a must-fix error in only 4 of the 201 reports. In total, there were 30 must-fix overview corrections spread across 29 reports; 4 were for a missing or unfinished overview, and the other 26 corrections were about overviews that were present but flawed.
Specifically, 12 of the 30 corrections noted that the overview missed the main trend or was too vague (for example, listing isolated maximum values or start and end figures instead of the overall direction, or overlooking a key category), 11 stated something the visual did not show (a wrong trend, a wrong direction such as west instead of east, an inverted comparison, or a wrong number of stages), and 3 were about wording. In one report at bands 6 to 6.5, for example, the writer overstated a trend by claiming one country led for the whole period when another country was higher in some years: "Malaysia stands the most share during the entire 70 years" → "Malaysia accounts for the highest proportion for most of the period" (bands 6–6.5).
Writing a paragraph that begins with Overall, is not enough on its own. Before moving on to your body paragraphs, a quick self-check can catch the two main overview problems: does my overview state the overall direction or the biggest category, and is every claim in it visible in the visual?
Which grammar and vocabulary mistakes hold back Task 1 scores?
Accurate data and a clear overview support Task Achievement (TA), which averages 5.43 at band 5.5 and below, 6.21 at bands 6 to 6.5, and 7.70 at band 7 and above. However, just as we saw in our study of how IELTS Writing Task 2 changes from band 6 to 7, language accuracy is the criterion that most often holds back a learner's overall Task 1 score in the middle bands.
| Band group | Reports | Task Achievement (TA) | Coherence & Cohesion (CC) | Lexical Resource (LR) | Grammar (GRA) |
|---|---|---|---|---|---|
| ≤5.5 | 42 | 5.43 | 5.29 | 5.14 | 5.01 |
| 6–6.5 | 62 | 6.21 | 6.23 | 6.02 | 5.81 |
| 7+ | 97 | 7.70 | 7.88 | 7.78 | 7.77 |
At bands 6 to 6.5, Grammatical Range and Accuracy averages 5.81 and is the lowest of the four criteria in 51% of reports (compared with 22% where Lexical Resource is lowest, 16% for Task Achievement, and 11% for Coherence and Cohesion). At band 5.5 and below, Grammar is also the most common weak point, acting as the lowest criterion in 40% of reports. At band 7 and above, no single criterion dominates as the weakest: Task Achievement is the lowest in 32% of reports, Grammar in 26%, Lexical Resource in 25%, and Coherence and Cohesion in 17%.
The share of reports containing must-fix language errors shows where marks are lost at bands 5.5 to 6.5. Must-fix article errors (a, an, the) appear in 55% of reports at 5.5 and below and 60% at bands 6 to 6.5, before dropping to 20% at band 7 and above; examples include "in 1990s" → "in the 1990s" and "in Philippines" → "in the Philippines" (bands 6–6.5). Must-fix spelling errors appear in 64% of reports at 5.5 and below and 55% at bands 6 to 6.5, falling to 16% at band 7 and above, including core Task 1 words like "percantage" → "percentage" and "biuldings" → "buildings" (both band 5.5 and below).
Other grammar and vocabulary errors follow a similar curve across the three groups. Verb tense or verb form errors fall from 62% of reports at 5.5 and below and 42% at bands 6 to 6.5 down to 16% at band 7 and above. Preposition errors drop from 55% and 40% to 9% at band 7 and above, while subject-verb agreement errors drop from 50% and 32% to 12%. One slip combined tense and unit mistakes in the same phrase: "stand at roughly 410" → "stood at roughly 410,000" (band 5.5 and below). On the vocabulary side, must-fix word choice errors appear in 62% of reports at 5.5 and below and 66% at bands 6 to 6.5, falling to 30% at band 7 and above. Word count is also worth watching: 26% of reports at 5.5 and below, 18% at bands 6 to 6.5, and 11% at band 7 and above were under the 150-word minimum.
How we counted
This analysis covers 384 writing responses submitted to IELTS Writing Checker between July and October 2026 by 62 learners: 201 Academic Task 1 reports from 37 learners (covering charts and graphs, process diagrams, maps, and tables) and 183 Task 2 essays from 41 learners. One learner accounted for nearly half of the reports at 7 and above, so Task 1 could not be split into finer bands and is grouped into three broad levels (5.5 and below, 6 to 6.5, and 7 and above). Repeated drafts of the same report were merged so that only the first draft was kept, texts mostly copied from published model answers were removed, and General Training letters were excluded because there were too few.
Every report was scored on the four criteria by IELTS Writing Checker, and our sentence-level corrections mark errors that "must fix". In our published accuracy study, on 73 officially scored responses, nearly 8 in 10 of IELTS Writing Checker's scores were within 0.5 points of the official score, with an average gap of 0.49 points. All findings reported here still held after removing the five learners who submitted the most reports. As a limitation, these scores are estimates rather than official IELTS results, and because the officially scored samples used in our accuracy study give only an overall score, the criterion-level pattern could not be checked against examiners directly.
If you want to see whether data slips, overview problems, or grammar errors are holding your own scores back, you can check a report with our IELTS Academic Writing Task 1 report checker.
Common questions
What is the most common mistake in IELTS Academic Writing Task 1?
Inaccurate or incomplete data description is the top must-fix error at every level (81% of reports at band 5.5 and below, 79% at bands 6 to 6.5, and 46% at band 7 and above), led by misread values or details and omitted categories.
Why is my Task 1 score stuck at band 6 or 6.5?
At bands 6 to 6.5, reports are held back by both data inaccuracies and basic language errors: 79% contain a must-fix data error and 23% have a must-fix overview problem. At the same time, Grammar is the lowest criterion in 51% of 6 to 6.5 reports (averaging 5.81), alongside frequent must-fix errors in word choice (66%), articles (60%), and spelling (55%).
What makes a band 7+ Task 1 overview different from a band 6.5 overview?
None of the 97 reports at band 7 and above had a must-fix overview error, compared with 36% at band 5.5 and below and 23% at bands 6 to 6.5. Across the 30 must-fix overview corrections in our dataset, only 4 were for a missing or unfinished overview, while 12 missed the main trend or were too vague and 11 stated something the visual did not show.
How common are unit mistakes in IELTS Task 1?
Missing or wrong units appear as a must-fix error in 12% of reports at band 5.5 and below and 13% at bands 6 to 6.5, dropping to 1% at band 7 and above.