Numbers, names and consistency: the errors hidden in facts

A proofreading test is not only about spelling and commas. Test writers also plant factual slips: a total that does not match its parts, a name spelt two ways, a date that says Tuesday when the calendar says Thursday, a figure that changes between paragraph one and paragraph three. This lesson shows how to check facts inside a passage against each other, and how to avoid flagging something that is not wrong.

The three kinds of factual error

• Internal mismatch. The passage contradicts itself. A letter says "three items" and then lists four. A total line does not equal the sum of the rows above it.
• Inconsistent form. The same thing is written two ways: "Mr Rajan" and "Mr Rajen", "10 March" and "March 10th", "e-mail" and "email". Either form may be correct alone; the error is the change.
• Impossible fact. A date like 31 April, a percentage above 100 for a share of a whole, or a time like 25:30.

Notice what is not on this list: facts you cannot check from the passage. If a letter says a meeting is on Monday 9 March and you do not have a calendar, you do not flag it. A guessed flag is a false flag, and it costs as much as a miss.

Worked example one: the invoice paragraph

"The order covers 12 chairs at 45.00 each and 2 tables at 180.00 each, a total of 880.00. Delivery is free on orders above 500.00. Please pay within 30 days of the invoice date, 14 June. Payments received after 14 June will carry a late fee." Check the arithmetic: 12 times 45 is 540, plus 2 times 180 is 360, so 900, not 880. Mark it. Then check the logic: the due date is 30 days after 14 June, but the last sentence charges a fee for anything after 14 June itself. Mark the contradiction.

Worked example two: the staff notice

"Priya Nair will lead the training on Friday 5 September. All staff should confirm attendance with Ms Nair by Thursday 4 September. Ms Naïr can be reached on extension 221." The accent on the third spelling is an inconsistency, so mark it. The dates are consistent with each other, so leave them. Do not change "Ms" to "Mrs"; the passage uses one form throughout.

Common mistakes

• Skipping the arithmetic because "it is a proofreading test, not maths".
• Marking a spelling variant that the passage uses consistently, such as "organise" throughout.
• Reading a number once. Read every figure twice, the second time digit by digit.

Practice habit: Take one real document a day, an invoice, a notice or a news paragraph with figures, and make a two-column list: every number and name on the left, where it appears again on the right. Any item that appears twice with a difference is your find. Ten minutes a day builds the reflex.