Prepared by Elisabeth Lindsay.
A spell checker is a feature of most word processing systems that allows a user to check and correct the spelling within a document or e-mail. When the user initiates a spell check, the system scans the document and compares the spelling of words to those of its built-in dictionary. If the system picks up a word it estimates to be misspelled, the user has the option to change, ignore, or add the word to the dictionary. Users can set preferences to have documents spell checked as they type, allowing them to correct spelling as they go. Along with a spell checker, a word processor may provide a grammar checker and thesaurus.
Spell checkers are useful tools for anyone, including genealogists, and are great for picking up typos (errors in typing) and truly misspelled words, but they are not fool-proof. For example, spell checkers do not pick up on words that sound alike but are spelled differently, or words that are spelled the same but have different meanings. A grammar checker may pick up on some context-sensitive errors in usage, but careful proof-reading by the writer or an editor is still important. It is a good idea for users to make sure a document has been "saved" prior to doing a spell check, in the event unintentional changes are made and one needs to return to the original document.