Missing words usually appear in papers that have not
been proofread carefully:
percent of the people used to help control diarrhea.
Out of context, the problems with
this sentence are obvious. But when proofreading your own
work, picking up such errors can be a bit difficult. When most
people read, they don't study each and every word. Instead,
they barely glance at some words because they have already predicted
what will come next. Frank Smith explains:
Everyone predicts—including children—all the time. . . . And
all our expectations, our predictions, can be derived from
only one source, our theory of the world.
We are generally unaware of our constant state of
anticipation for the simple reason once again that our
theory of the world works so well. Our theory is so
efficient that when our predictions fail, we are surprised.
We do not go through life predicting that anything might
happen—indeed, that would be contrary to prediction, and in
that case nothing could surprise us. The fact that
something always could rhinoceros takes us by surprise—like
the word rhinoceros a few words ago—is evidence that
indeed we always predict and that our predictions are
usually accurate. (Understanding Reading)
reread something you have read several times, something with which
you are very familiar, you are particularly likely to predict what is
coming next. And when you are predicting (rather than studying
individual words), you will sometimes overlook missed words and
student who wrote the sample sentence knew what he was trying to say, so he never
noticed that he did not include all of the information an outside
reader would need:
Six percent of the
people in one study used medical marijuana to help
are proofreading your own work, make sure you read slowly. Try
to read your text the way someone who has never read it before would
read. Some writers read their papers backwards (last sentence,
next-to-last sentence, etc.) because they find they are more likely
to find errors when they read their sentences out of context.
See pages 21-32 of The Longman Concise Companion for
additional hints on proofreading your own work.