IGCSE ICT: Proofing — Revision Notes

Proofing in Cambridge IGCSE ICT 0417 (Topic 15) is about reducing errors: using spell and grammar checkers sensibly, using validation routines to stop unreasonable data being entered, verifying data by visual checking or double data entry, and proofreading documents for layout and consistency errors. You must also explain why validation and verification are both needed, a frequent Paper 1 question.

Condensed for revision. For the full explanation, use the proofing study guide, then try the proofing practice questions.

Syllabus coverage

Syllabus ref	Be able to	Know and understand
15.1 Software tools	Use spell check and grammar check and make appropriate changes; use validation routines to minimise data entry errors	Spell check suggestions are not always correct; importance, characteristics and uses of range, character, length, type, format and presence checks
15.2 Proofing techniques	Visual verification: correct transposed numbers, incorrect spelling, inconsistent character spacing, inconsistent case. Proofread: correct inconsistent line spacing, remove blank pages/slides, remove widows/orphans, fix inconsistent or incorrect styles, keep tables and lists from splitting over columns or pages/slides	Importance, characteristics and uses of verification (visual checking, double data entry); the need for validation as well as verification

15.1 Why can’t you trust a spell checker completely?

Spell check compares words with a dictionary and suggests corrections, but:

• A correctly spelled wrong word is not flagged (their / there, form / from).
• Names, technical terms and words in another language may be flagged even though they are right.
• The first suggestion may not be the word you meant.
• The dictionary language may be wrong (for example US instead of UK spelling).

Grammar check finds some errors (for example subject–verb agreement) but can also suggest changes that alter the meaning. Always read the suggestion before accepting it.

Validation checks

Validation is an automatic check by the computer that data entered is reasonable and sensible and follows set rules. It cannot tell whether the data is correct.

Check	What it checks	Example
Range check	Value is between a lower and upper limit	Percentage between 0 and 100
Character check	Only permitted characters are present	A surname contains no digits or symbols other than hyphen or apostrophe
Length check	Number of characters is exact or within limits	Password of at least 8 characters
Type check	Data is the correct data type	Quantity is a number
Format check	Data matches a pattern	Postcode or a date in DD/MM/YYYY form
Presence check	Data has been entered; field is not blank	Email address is required

15.2 What is verification?

Verification checks that data has been copied or entered accurately from the source.

Method	How it works	Limitation
Visual checking	The person compares the entered data with the source document on screen or paper	Slow; the checker can miss errors, especially if tired
Double data entry	Data is entered twice (often by two people); the computer compares the two and flags differences	Takes twice as long; if both entries have the same mistake it is not found

Why are both validation and verification needed?

• Validation can accept data that is reasonable but wrong — a date of birth typed as 12/05/2009 instead of 21/05/2009 passes a format check.
• Verification can confirm data was copied accurately, even when the source itself was unreasonable — an impossible value copied faithfully would pass.
• Used together they catch more errors: validation stops unreasonable data, verification stops copying mistakes.

Visual verification: errors to find

Error	Example
Transposed numbers	1532 typed as 1352
Incorrect spelling	“recieve” for “receive”
Inconsistent character spacing	Two spaces after some full stops and one after others
Inconsistent case	“Price”, “price” and “PRICE” used for the same heading

Proofreading a document: what to check

• Inconsistent line spacing between similar paragraphs.
• Blank pages or blank slides that should be removed.
• Widows and orphans: a widow is the last line of a paragraph left alone at the top of a new page or column; an orphan is the first line of a paragraph left alone at the bottom of a page or column. Remove them by adjusting breaks or using the widow/orphan control setting.
• Inconsistent or incorrect application of styles — every heading should use the heading style.
• Tables and lists split across columns, pages or slides — keep them together.

Worked example: validation or verification?

A clerk types a customer’s phone number, 07700 900123, as 07700 900132.

• A length or format check will accept it: it still has the right number of digits.
• Only verification (visual check against the form, or double entry) would find the transposed digits.

Common mistakes and exam traps

• Saying validation checks that data is “correct”. It checks that data is reasonable.
• Calling double data entry a validation check. It is a verification method.
• Describing a check without giving an example linked to the field in the question.
• Mixing up widows and orphans, or not knowing they relate to page and column breaks.
• Accepting every spell-check suggestion in the practical papers, including changing correct names.

Frequently asked questions

What is the difference between validation and verification? Validation is an automatic check that data is reasonable and follows the rules, such as a range check. Verification checks that data has been entered exactly as it appears in the source, by visual checking or double data entry.

Why is a spell checker not enough to proofread a document? It only finds words that are not in its dictionary. Real words used wrongly, inconsistent spacing or case, and layout errors such as widows and split tables must be found by proofreading.

Which check would stop a field being left blank? A presence check. It makes sure data has been entered before the record can be saved.

What is a transposition error? Two characters are swapped, such as 47 typed as 74. Visual verification or double data entry can find it; most validation checks cannot.

Self-test

1. Name the validation check for a password that must have at least 8 characters.
2. Give two reasons why spell-check suggestions may be wrong.
3. Describe double data entry.
4. Define a widow.
5. Explain why validation alone is not enough.

Answers: 1 length check; 2 correctly spelled wrong word not flagged, names flagged, wrong dictionary language, first suggestion not the intended word; 3 data entered twice and the computer compares the two versions and reports differences; 4 last line of a paragraph alone at the top of a new page or column; 5 data can be reasonable but still wrong, such as transposed digits.

Official syllabus

Cambridge International, Cambridge IGCSE Information and Communication Technology (0417) syllabus for 2026, 2027 and 2028, Version 3, Topic 15 “Proofing” (15.1 Software tools, 15.2 Proofing techniques).