Proofreading your written English work

Each line of the essay extract contains zero, one, or two mistakes.

When you are going through the process of proofreading you can sometimes over-correct a piece of writing. Although it is sometimes necessary to improve for example, the way you have expressed a point, too much time spent changing words can start to be detrimental. If you have identified more mistakes than those indicated below, consider how this might have happened.

The number of mistakes in each line of the introduction are as follows:

1 Continuing advance in Computer Science have steadily increased the
2 reliability which can be achieved in computer controled equipments.
1 A growing number of routine functions were now automated leaving
0 human operators with the overall control and the necessary
2 supervisory tasks. As overall controllers these operators are guiding
2 the computer by initiating the desired actions and, choose appropriate
2 modes. As supervisors, they must to monitor the system, to judge of
2 the computers actions and to correct rapidly faults if necessary. The
1 problem with the latter task is that, in complexed systems such as
2 nuclear power plant, there is often no independent way for operator
1 assessing the state of the monitoring process; for this she depends
1 entirely on information providing by the computer. This means that the
1 operator must be able to trust the computer despite of the need to
1 accept that some of its actions could be faultly. In this essay, the
0 dangers of both mistrust towards computers and of over reliance on
1 them are illustrated with examples of accidents which were down to
0 such attitudes. Finally, three factors which could encourage an
0 appropriate attitude of operators towards computers are suggested.

1 Continuing advances in Computer Science have steadily increased the
2 reliability which can be achieved in computer controlled equipments equipment.
1 A growing number of routine functions were are now automated leaving
0 human operators with the overall control and the necessary
2 supervisory tasks. As overall controllers, these operators are guiding guide
2 the computer by initiating the desired actions and (comma deleted) choose choosing appropriate
2 modes. As supervisors, they must to must / have to monitor the system, to judge of
2 the computer's actions and to correct rapidly faults rapidly if necessary. The
1 problem with the latter task is that, in complexed systems such as
2 nuclear power plants, there is often no independent way for operators
1 assessing to assess the state of the monitoring process; for this she depends
1 entirely on information providing provided by the computer. This means that the
1 operator must be able to trust the computer despite of despite / in spite of the need to
1 accept that some of its actions could be faultly faulty. In this essay, the
0 dangers of both mistrust towards computers and of over reliance on
1 them are illustrated with examples of accidents which were down to the result of
0 such attitudes. Finally, three factors which could encourage an
0 appropriate attitude of operators towards computers are suggested.

Laura's introduction contained a number of typical mistakes that could be identified by proofreading. Here is a summary of the types of corrections that Laura needs to make in her work:

tenses (present simple - are, guide)
modal verbs (must/have to)
more formal choice of words (the result of; down to = informal)
use of linking expressions (despite/in spite of)
reduced relative clause( provided adj.)
word order (to rapidly correct)
infinitives and gerunds(to assess; choosing)
form of adjectives( complex; faulty)
uncountable nouns (equipment)
singular and plural noun forms (nuclear power plants; advances)
punctuation ( commas)

When correcting your own work, it can help to consider the types of mistakes that you often make and to check your work for mistakes in these areas in particular.