What Is a Diagram Label Completion Question?

This task requires you to label parts of a diagram or illustration using information from the reading passage.

The diagram could show:

A biological process (e.g., parts of the heart)
A mechanical system (e.g., how a wind turbine works)
A map, plan, or structure

Your task is to fill in the blanks using words from the passage. Sometimes, a word box is provided; sometimes you must find the words yourself.

What Is the Examiner Testing?

This task checks if you can:

Understand visual representations
Identify and match descriptions in the passage to diagram labels
Recognise parts of a process or structure
Follow spatial/positional language (e.g., “above,” “to the left of”)

Common Mistakes Students Make

Matching labels based on position only, not meaning
Using words not found in the passage
Breaking the word limit
Ignoring grammar/context clues in labels
Overlooking reference points in diagrams (arrows, parts, etc.)

Step-by-Step Strategy

Step 1: Analyze the Diagram
- Look for:
  - Arrows → show direction or sequence
  - Labels → see what kind of words are missing (nouns, numbers, locations)
  - Diagram Type → process? object? biological part?
Step 2: Read the Instructions Carefully
- Check if the answers:
  - Must be chosen from a list
  - Must be taken directly from the passage
  - Have a word limit (e.g., “No more than TWO words”)
Step 3: Predict the Kind of Answer Needed
- Is it a tool, material, stage, part?
Step 4: Use Keywords from the Diagram to Locate the Text
- Find the relevant part of the passage that matches the section of the diagram you’re working on.
Step 5: Match the Idea and Copy Exactly
- Ensure the word from the passage:
  - Matches the label’s meaning
  - Is spelled correctly
  - Respects the word limit

Cambridge-Style Example with Explanation

Passage Excerpt:

The water purification process begins with the intake of raw water. It first passes through a coarse filter to remove large debris. Then, it flows into a sedimentation tank where heavy particles settle. The next stage is the chemical treatment where chlorine is added. Finally, the clean water is stored in reservoirs.

Diagram (Simplified Text Version):

Water Purification Process-

Step 1: Raw water

Step 2: Passes through

Step 3: Enters sedimentation

Step 4: Treated with

Step 5: Stored in

Show Answer

Answers:

coarse filter
tank
chlorine
reservoirs

Why?

Each answer is a noun directly matching the diagram and clearly stated in the passage. The order also matches the process.

Band 5 vs Band 8 Thinking

Band 5 Learner	Band 8 Learner
Labels by position only	Matches diagram to detailed description
Chooses a similar word	Looks for exact match in passage
Misses word limit	Double-checks every instruction
Doesn’t check grammar	Ensures answer fits grammatically

Common Traps to Avoid

Trap	Fix
Matching visual shape, not description	Always match meaning, not looks
Using general knowledge	Use only the passage
Changing word form	Copy exactly as shown in passage
Ignoring arrows/sequencing	Follow the diagram’s direction carefully

Quick Tips – Do vs Don’t

Do	Don’t
Understand the whole process	Guess from the picture only
Use the correct word from text	Use your own words or reword
Check spelling and word limit	Add extra or wrong word forms
Read all instructions	Assume it’s the same as other tasks

Mini Quiz

In photosynthesis, sunlight is absorbed by chlorophyll in the leaves. Water enters through the roots and carbon dioxide through tiny pores called stomata. The process produces glucose and oxygen.

Diagram: Plant Photosynthesis

Sunlight captured by

Water enters via

CO₂ absorbed through

Show Answer

Answers:

chlorophyll
roots
stomata

Related Resources

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Final Advice from Your Tutor

Diagram Label Completion is a visual test of your reading accuracy.
You must translate what you read into labelled understanding — while being exact.
Follow these principles:
- “Visual thinking + accurate scanning = high score.”
This is a powerful question type once you learn how to match words to visuals.
Practice this well, and your reading fluency will grow fast.