Avoid “Whiz Deletions”
So-named because they are examples of zealous over-editing, whiz deletions happen when the editor strikes out the relative pronouns which and that.
Dominique Joseph has commented on these elsewhere:
As a Francophone and a translator, I can confirm that keeping the “whiz” words in makes the text clearer and easier to understand. When “whiz” words are deleted, it can be tricky to figure out the underlying structure of the sentence and the relationships between words or ideas.
1. From “Rules for writing plain English”, by Bill Lutz (http://www.plainlanguagenetwork.org/Resources/lutz.htm#anchor)
Bill Lutz says we should avoid “whiz deleletions”, which he explains as follows:
Subordinate clauses are often introduced by such words as “which is,” “who was,” “that are,” etc. Deleting these words (the relative pronoun and linking verb) is known as “whiz-deletion.” For example:
1.The supervisor wants the report which was written by the Purchasing Office.
With a whiz-deletion we get:
2.The supervisor wants the report written by the Purchasing Office.
The whiz-deletion makes sentence 2 ambiguous. Does the supervisor want the Purchasing Office to write the report, or does she want the report that the Purchasing Office has already written? Generally, it’s a good idea to avoid whiz-deletions.
(source: http://www.plainlanguagenetwork.org/Resources/lutz.htm#anchor)
2. From “Revisiting Plain Language”, by Beth Mazur (http://www.plainlanguage.gov/whatisPL/history/mazur.cfm)
One such guideline is the suggestion to “avoid whiz deletions.” A whiz deletion is the absence of introductory text for subordinate clauses. The Guidelines offer the comparison between the sentence “The director wants the report which was written by the Home Office.” and “The director wants the report written by the Home Office” (Felker and others 1981, pp. 39-40). This guideline was based on direct research done by Charrow and Charrow (1978). In their extensive study of jury instructions, these authors found that whiz deletions made jury instructions harder to understand (Felker and others 1981).