Spot the difference

Why this shape

The differences between two images test attention to detail: inspection, proofreading, safety checks.

An example. Click the three differences between the before and after photographs.

What it is

Spatial and visual questions put an image in front of the student and ask them to act on it: click a part, outline a region, label, build, find a place on a map. The answer is a position or a structure, not a word.

Why it is needed

In anatomy, geography, engineering, art and every field with diagrams, knowing where a thing is matters as much as knowing its name. A hotspot question has no text to copy into a chatbot and no option to recognise: the student has to know where to click. It is one of the shapes that defeat cheating by its nature.

When to use it

Use it wherever the material is a picture, a diagram, a map or a chart: label the parts, locate the fault, find the country, pick the correct reading on a gauge. Use it for young learners, who can point before they can write.

How to write one well

Use a clear image at a size that fits a phone. Draw the accepted region generously enough that a right answer is not marked wrong for a pixel, and tightly enough that a guess is not rewarded. Ask for one thing per question.

For spot the difference in particular. Make the differences matter to the subject, not to the eye alone.

Mistakes to avoid

A region so small that a finger cannot hit it. An image that gives the answer away with a label. A question that needs two clicks but accepts one. A map projection that makes the place ambiguous.

How EdProcto marks it

EdProcto marks a hotspot by rule: the click must land inside the region you drew, stored as fractions of the image so it works at any size. The region never leaves the server, so the student's page shows the image and nothing else. Free drawing, labelling and building shapes are marked by a reader against your rubric.