A student sees a line graph:
January: 20
February: 24
March: 27
April: 26
May: 35
They write one sentence for every value.
Every number is correct. The description is weak.
Why?
Because the graph has been converted into a list.
A stronger version is:
The value rose gradually from January to March, dipped slightly in April, then increased sharply to its highest point in May.
Good graph writing preserves the pattern rather than transcribing every point.
Visual data needs a verbal model
A graph already compresses information visually.
Writing about it requires a second representation:
visual pattern → language
The student must decide what matters, what can be grouped, what should be compared and what can be omitted.
Start with orientation
Before writing a trend sentence, identify:
- what is being measured;
- horizontal axis;
- vertical axis;
- units;
- time period or categories.
A beautifully written sentence about the wrong variable is still wrong.
Find the overview
Ask:
What would I say if I could keep only one sentence?
Perhaps:
Sales rose overall despite a brief mid-year decline.
Or:
The two groups followed similar trends until 2024, after which Group A increased more sharply.
The overview gives the reader a map.
Select high-information features
Look for:
highest point
lowest point
overall direction
sharp change
reversal
plateau
gap between groups
outlier
These usually matter more than repeating every data point.
Trend vocabulary carries shape
rise
fall
increase
decrease
decline
peak
remain steady
level off
Students should learn the visual pattern behind each term.
Direction and degree work together
rose slightly
increased steadily
climbed sharply
fell dramatically
If a value moves from 100 to 101, surged is probably misleading.
The graph decides the intensity.
Peak and low point compress information
Sales peaked in May at 35 units.
This is more efficient than explaining separately that May was the highest month.
Fluctuate requires repeated movement
A single rise followed by one fall is not necessarily a strong fluctuation pattern.
Words such as wildly add even more degree and should be justified visually.
Tables require comparison when time is absent
| Region | Recycling Rate |
|---|---|
| A | 62% |
| B | 48% |
| C | 63% |
A useful sentence is:
Regions A and C recorded similar rates at around 63%, whereas Region B was about 14–15 percentage points lower.
The structure is comparative, not temporal.
Preserve units
If a rate rises from 40% to 60%, the change is:
20 percentage points
and also:
50% relative to the original 40%
Those are not identical expressions.
English accuracy includes quantitative accuracy.
Twice as many is not 200% more
If A = 20 and B = 10, A is twice as large as B and 100% larger than B.
Graph writing quickly exposes numerical-language errors.
Do not invent causation
If screen time rises while sleep duration falls, a graph may show association.
It does not automatically prove:
Screen time caused the decline in sleep.
Safer:
The two variables moved in opposite directions over the period.
Causal interpretation requires additional evidence.
Do not describe what the graph did not measure
If a chart measures reported stress, do not rewrite it as mental illness.
If it measures attendance, do not claim motivation improved.
The visual has a measurement boundary.
Graph literacy is learned
Recent research on visualisation literacy shows that people can identify a chart’s topic while missing deeper trends, anomalies or structural relationships.
Seeing a graph is not the same as reading it.
Graph description also creates grammar demands
The student must coordinate data interpretation with tense, subject–verb agreement, prepositions, articles and sentence structure.
That makes graph writing a genuine cross-curricular English task.
Tense follows the data time
Historical:
Sales rose between 2018 and 2022.
Current description:
The chart shows…
Forecast:
Demand is projected to increase.
A projection should not be silently rewritten as an observed fact.
A four-layer graph-reading method
- Orientation: axes, categories, units.
- Overview: main pattern.
- Evidence: two or three values that demonstrate it.
- Boundary: what the visual does not establish.
Graph design can influence interpretation
Readers should notice:
axis scale
missing baseline
unequal intervals
selected date range
absolute numbers vs percentages
Critical visual reading is part of modern literacy.
Singapore English already crosses into visual information
Secondary English increasingly involves reading and viewing across print, non-print and digital sources.
Students need to translate among:
image
chart
language
argument
Summary writing and graph writing share a mechanism
Both ask:
What can I leave out without losing the essential structure?
Both require selection, grouping, comparison and fidelity.
Parent-friendly practice
Use a simple chart.
Ask:
What is the one-sentence story?
Which two numbers prove it?
What conclusion would be too strong?
Teacher-friendly diagnosis
Orientation error: wrong variable or unit.
Selection error: too many numbers, no pattern.
Comparison error: values described separately.
Degree error: dramatic vocabulary for tiny change.
Causal overreach: association described as cause.
Hilary Mantel as a high-level lens
A strong description does not list everything visible. It selects the detail that carries the scene.
Graph writing uses the same high-level discipline in a different register:
Which data point carries the pattern?
AI and graph description
AI can misread axes, round inaccurately, invent causes or miss anomalies.
Verify variables, units, cited values, trend direction and causal wording against the visual itself.
Connections eduKateAI can learn
visual data → variables/units → pattern → selected evidence → prose
trend → direction + degree + time
overview → high-information compression
graph association → not automatic causation
AI graph description → number/unit/trend/causality audit
The public principle is that writing about data is a representation task: prose should preserve the visual structure without inventing relationships the visual does not establish.
Related eduKateSG resources
Research basis
This article draws on current University of Manchester Academic Phrasebank trend language, IELTS Academic chart-description guidance, Singapore Secondary English visual-text expectations and recent visualisation-literacy research.