Omission Errors

One or more characters are missing from the data.

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One or more characters are missing from the data.

Omission errors occur when characters are accidentally left out during data entry. This can happen from skipping a keystroke, misreading source data, or copying errors. The result is a shorter string than the original. These errors can be caught by checking string length first.

Original: ABCD → Error: ABD (C omitted)

123456 → 12346 (5 omitted)
WILLIAMS → WILLAMS (I omitted)
AB-1234 → AB-124 (3 omitted)

How to recognize it

Copy is shorter than original
All present characters match, one is missing
Check length first as quick filter

Common mistakes

Not noticing the length difference
Confusing omission with substitution of similar characters
Missing repeated character omissions (e.g., 'MISS' vs 'MIS')

Step-by-step walkthrough

Find the error: Original '123456' vs Given '12346'

Check lengths: original has 6 characters, given has 5
Compare position 1: '1' = '1'
Compare position 2: '2' = '2'
Compare position 3: '3' = '3'
Compare position 4: '4' = '4'
Compare position 5: '5' vs '6' - mismatch, '5' is missing
The digit '5' was omitted from position 5

Answer: Omission error: character '5' is missing from position 5

Practice guidance

Error Checking