Error checking test: how to spot mistakes fast and accurately
An error checking test measures attention to detail under time pressure: you compare codes, numbers or records against an original and find the ones that match exactly or contain errors. The errors are predictable: swapped neighbours, look-alike characters, one changed digit, or a missing character. Checking in small chunks is faster and more accurate than reading the whole string. These tests appear in finance, operations and admin hiring, and in batteries such as Korn Ferry's Aspects Ability.
- Compare items against an original and find exact matches or errors.
- Four hidden errors: swaps, look-alikes, changed digits, missing characters.
- Chunk into groups of 3–4 characters.
- Korn Ferry's Aspects checking test takes about 6 minutes.
- Speed and accuracy are both scored. Get accurate first.
Free sample question
Find the exact match
One original code, four copies. Three contain a hidden error. Pick the exact match.
One question in the real format, with the worked solution · no signup
Quick summary
- Error checking tests compare data against an original.
- Errors are usually swaps, look-alikes, single changes or missing characters.
- Check in chunks of three or four characters.
- Read numbers as groups, not single digits.
- Build accuracy first, then push the pace.
The four errors to look for
| Error | Original | Copy |
|---|---|---|
| Swapped neighbours | KX47-219B | KX74-219B |
| Look-alike characters | B08-5SO | B08-5S0 |
| One changed character | TR-48321 | TR-48371 |
| Missing or extra character | QL-9930-A | QL-930-A |
A method that works
- Split at natural breaks (dashes, spaces) or into chunks of three or four.
- Compare chunk by chunk, saying each chunk silently.
- Check the length: a missing character often shifts everything after it.
- Slow down on look-alikes: 0/O, 1/I/l, 5/S, 8/B, 2/Z.
Free sample question
Count the letters
Count one target letter in a grid of look-alikes (b, d, p, q). A classic concentration task.
One question in the real format, with the worked solution · no signup
Practise checking and concentration on forge
Korn Ferry Aspects-style checking tests, plus the free Aon-style concentration game.
Start checking practiceRelated guides
- Cognitive ability tests
- Talent Q Aspects test
- CCAT logic and attention questions
- Time management in tests
Source notes
The Aspects Ability checking test description and its approximate 6-minute duration come from Korn Ferry's Talent Q Aspects psychometric review (checked 2 October 2026). All examples and game items are written or generated by forge. forge is independent and not affiliated with Korn Ferry or Aon.
Frequently asked questions
What is an error checking test?
A timed test of attention to detail. You compare codes, numbers, names or data against an original and identify which match exactly and which contain errors. It is sometimes called a clerical checking or perceptual speed test.
Which jobs use error checking tests?
Administrative, finance operations, banking, data entry, compliance and customer service roles, plus some graduate schemes as part of a wider battery. Korn Ferry's Aspects Ability includes a checking test.
How do I get better at error checking?
Compare in small chunks of three or four characters, read numbers as groups ('47-21' rather than 'four, seven, two, one'), and watch for look-alike characters and swapped neighbours. Accuracy first, then speed.
What errors do checking tests hide?
Swapped adjacent characters (4721 vs 4712), look-alike characters (0/O, 1/I, 5/S, 8/B), a single changed digit, and missing or extra characters.
How long are error checking tests?
They are usually short. Korn Ferry's Aspects Ability checking test takes about 6 minutes, for example. The time pressure is the point: the test measures speed and accuracy together.
Sharpen your eye for detail
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