Short answer: IELTS flow-chart, diagram and table completion tasks give you a visual summary of part of the passage with gaps to fill using words copied from the text, under a strict word limit.
They appear most often on process passages (how something is made or done) and descriptive passages. The marks are won by reading the chart structure first, respecting the word limit, and copying each answer exactly.
These three tasks look different on the page — a chain of boxes joined by arrows, a labelled picture of a machine or a natural object, a grid of rows and columns — but they are the same job wearing three costumes.
Each gives you a visual reorganisation of information from the passage and asks you to complete it with words the text supplies. The candidates who lose marks here are usually those who dive at the gaps without first reading what the chart, diagram or table is actually representing.
This guide explains where these tasks appear, why you should read the structure before the gaps, how the word limit works, how to follow a process through the text, a worked example in the test's style, and how to drill the type.
Where this appears (process and description passages)
Flow-chart and diagram completion are not sprinkled at random across the Reading paper — they are attracted to particular kinds of passage, and knowing this helps you anticipate them.
Flow-charts attach to process passages: text that explains how something happens in stages — how a material is manufactured, how a natural cycle turns, how a system processes an input into an output.
Diagram labelling attaches to descriptive passages: text that describes the parts of a physical object — a piece of equipment, an animal, a building, a geological feature — where the passage names components you then place on a picture.
Table completion attaches to passages that compare or classify: text that sets several things against shared categories, which the table then organises into rows and columns.
Recognising the passage type early tells you which task is likely coming and how to read. A process passage rewards reading for sequence and signposts — first, next, once this is done, the resulting — because the flow-chart will mirror that sequence.
A descriptive passage rewards attention to the names of parts and their spatial relationships.
This is a different reading mode from the gist-first skim that suits matching headings, and knowing which mode a passage demands is a large part of reading efficiently, as our overview of the IELTS question types lays out.
Read the chart structure first
Before you hunt for a single answer, spend twenty seconds reading the chart, diagram or table as a whole. The structure is not decoration — it encodes information you can use.
In a flow-chart, the arrows tell you the direction of the process and the boxes tell you the stages; the words already printed in the boxes tell you roughly where in the passage each gap lives, because the chart follows the text's sequence.
In a diagram, the existing labels and the position of each empty label line tell you which part of the object you are naming.
In a table, the row and column headings define exactly what kind of information each cell wants — a date, a name, a quantity, a feature.
Reading the structure first does two things. It gives you a map, so each gap becomes "find the stage between X and Y" rather than "find something, somewhere".
And it lets you predict the grammar of each gap, which is the highest-value habit in every completion task: decide whether the gap needs a noun, a verb or an adjective before you search.
A gap after "the" wants a noun; a gap in a box that reads "the mixture is then ______" wants a verb or a past participle.
Jotting n., v. or adj. beside each gap costs seconds and stops you copying a thematically-right, grammatically-wrong word from a sentence near the real answer.
Word limit and exact-word copying
Like the other completion tasks, these are governed by a word limit stated in capitals — commonly NO MORE THAN TWO WORDS AND/OR A NUMBER — and IELTS enforces it to the letter. Exceed the limit and a correct idea scores zero.
The counting rules are the same across every Reading completion task, and they are worth knowing cold.
| Task | What you fill in | Follows passage order? | Main difficulty |
|---|---|---|---|
| Flow-chart completion | Words copied into process-stage boxes | Usually yes — mirrors the process sequence | Matching a box to the right stage in the text |
| Diagram labelling | Words copied onto label lines of a picture | Often no — labels can be out of order | Locating a part by its function or position |
| Table completion | Words copied into cells under row/column headings | Usually yes — rows follow the text | Reading the wrong row or column |
Two mechanical rules protect your marks. First, copy the answer exactly as the passage spells it — these are lifted words, spelling is marked, and while IELTS accepts standard British and American variants such as fibre and fiber, it accepts no invented ones.
Second, never add words the gap does not need; if the box already contains "the", do not copy another article.
And crucially, the word you write must make grammatical sense in the chart, not in the original passage sentence — the chart has reworded the idea, so read the completed box back to yourself to confirm it reads as a sentence.
Make word-counting a ritual: touch a finger for each word before you commit.
Following a process in the text
Flow-charts and process passages demand a specific reading skill: tracking a sequence of stages through prose that signals order with connective language rather than numbered steps.
The passage will not say "Step 3"; it will say once the pulp has been washed, it is then pressed, after which the sheets are left to dry. Your job is to map that running sentence onto the chart's boxes.
Train your eye to catch the sequence signposts — first, initially, then, next, after this, once, following, subsequently, finally, the resulting — because each one marks the boundary between one flow-chart box and the next.
Because a flow-chart mirrors the process, its gaps usually appear in the passage in the same order as the boxes, so your search only ever moves forward.
Use that: anchor on the box before your gap, find its stage in the text, and the answer to the gap will be in the next stage described.
Diagram labelling behaves differently — a description of an object may name the parts in any order, top to bottom one moment and inside to outside the next — so for diagrams you locate each label by its feature or position rather than by sequence.
Managing the clock across a whole process passage, where one confusing stage can stall you, is exactly the triage our IELTS Reading time management guide is built around, and the paraphrase-heavy locating these tasks require is the same skill you drill for summary and sentence completion.
A worked example
The passage and flow-chart below were written for this article as a teaching example, in the style of a test paper. Read the passage for its sequence.
"The production of cane sugar begins in the field, where the mature stalks are cut and carried quickly to the mill, because the sugar content starts to fall as soon as the cane is harvested. At the mill, the stalks are first crushed between heavy rollers to squeeze out the juice. This raw juice is then heated and treated with lime, which makes the impurities clump together so they can be removed. The clarified juice is boiled until it thickens into a syrup, and as the syrup cools, sugar crystals form and are finally separated from the remaining liquid in a spinning machine."
Flow-chart (complete each gap, NO MORE THAN TWO WORDS): Cane is cut in the field → stalks are crushed between (1) ______ to extract the juice → juice is heated and treated with (2) ______ to remove impurities → juice is boiled into a (3) ______ → crystals are separated using a (4) ______.
Read the chart's structure first: it is a five-stage process and the boxes mirror the passage's sequence, so each answer lies below the last. Now predict grammar and locate.
Gap 1 follows "crushed between", so it wants a noun for the crushing tool — the passage says "crushed between heavy rollers", giving heavy rollers (two words). Gap 2 follows "treated with", wanting a noun — the passage says "treated with lime", giving lime.
Gap 3 follows "boiled into a", wanting a noun — the passage says "boiled until it thickens into a syrup", giving syrup.
Gap 4 follows "using a", wanting a noun for the machine — the passage says crystals are "separated from the remaining liquid in a spinning machine", giving spinning machine (two words).
Notice what did the work: the chart's arrows told you the answers ran in order, the grammar of each gap told you every answer was a noun, and the sequence signposts — first, then, until, finally — marked the boundary of each stage.
A candidate who read the chart structure before scanning filled all four gaps by following the process straight down the passage, and each answer was copied exactly, within the limit.
Deliberate practice
These tasks reward volume because the skill is mechanical and pattern-based: the more process and descriptive passages you work, the faster you become at reading a chart's structure, predicting gap grammar, and mapping sequence language onto boxes.
A single official Reading test rarely gives you more than one flow-chart or diagram, which is not enough repetition to make the routine automatic.
That volume gap is what IELTSbiz practice fills — it generates fresh Cambridge-style passages aimed at a single question type, flow-chart and diagram completion among the eleven supported, and when you fill a gap wrongly the feedback shows whether you broke the word limit, chose the wrong grammar or read the wrong stage.
Per-type band tracking then tells you whether these visual tasks are genuinely dragging your Reading score.
Combine that with official timed practice so your reading speed is calibrated to real process passages — the British Council's free Reading practice tests are the benchmark — and read well-edited explanatory English regularly, such as the free materials in the Cambridge English learning resources, to make sequence-tracking feel natural.
The habit of reading with a target — chart structure first, then a forward-only search — is what turns these from fiddly puzzles into some of the most reliable marks on the paper.
Conclusion
Flow-chart, diagram and table completion are the Reading paper's visual tasks, and they attach to predictable passage types: flow-charts to processes, diagrams to descriptions, tables to comparisons.
Read the structure before the gaps — the arrows, labels and headings tell you what each gap needs and, in a flow-chart or table, that the answers run in order.
Predict the grammar of every gap, follow the sequence signposts through the text, and copy each answer exactly within the word limit, reading the completed box back to confirm it makes sense. For diagrams, locate each label by its feature or position rather than by sequence.
Drill the type for volume, respect the word limit as a contract, and these tasks stop being fiddly and start being dependable.