John Gibson
Our own native tongue is the first foreign language we learn and
(ideally) we learn that language from a well-educated parent.In the matter of correcting the mistakes made by a student (of any age) of a foreign language there is only one correct attitude for the teacher: that of a well-educated, caring and ever-present parent towards his or her child learning their native tongue. "Well-educated" in this context means: "fully understanding the appropriate current and increasing language-needs of that particular child/pupil and observing and recognising the child's/pupil's readiness for the next step in language development."
In general such a parent/teacher normally utters a correction the first time in a conversation that the child/pupil makes a mistake and requires the child/pupil at once to imitate the correction. This is also a critical time for correct (that is, the most desirable) pronunciation to be stressed and properly imitated and for all the muscles used for that speech to be fully worked and developed in order to avoid a belated need for so-called "speech-therapy".
Repetition of a specific correction becomes less frequent according to (a) the child's/pupil's eagerness to avoid repetition of the mistake and (b) the place the child/pupil occupies in his personal "learning-curve".
Unfortunately for us all, our personal "learning-curve" progressively becomes less steep every day (until in adults it no longer exists), having been inadequately replaced by nothing better than the dubious impulse the behavioural psychologist calls "Motivation".
To sum up: the ideal pattern for correction is an individual matter for mutual agreement between an eager pupil and a competent and willing teacher. It is pointless to search for modifications to this rule in order to try to accommodate antagonistic forces such as too many pupils per teacher. Everything said here applies equally (as appropriate) to oral and written language learning and teaching.

Yubaraj Pandey, Nepal
I try to mark the mistakes I recognize and give the pupil a chance to find out himself what is wrong. If he cannot find the correct solution, only then do I help him. this makes them think rather than just copy what I put over his erroneous version.

Jérôme Quintana, France
It really depends what you mean by 'correcting'. The most active - and probably effective - way of dealing with students' errors in written work is to highlight / underline their mistakes, possibly indicating the sort of errors(grammar, vocab, sentence structure, etc.) and have the students correct their own mistakes (all or some of them). Correction work can be rewarded with either a grade or a bonus mark. You may obviously correct some errors yourself if you think it is beyond the students' grasp or level.

Philip, Rome
Avoiding mistakes in written English is very difficult for students, so they need to be aware of this at the outset and be encouraged to look upon the exercise in a positive way i.e. to learn from and try to avoid repetition of their most frequent mistakes. However, written text remains a source of reference for students and as such must not become a source of error, consequently it's important to correct the errors. However, students soon improve if given help and encouragement, and this is then reflected in their spoken use of the language. In my experience, after the initial disappointment of more errors than they hoped for, they begin to appreciate writing as a tool for improving their knowledge and use of the language.

Francisco João Aristides, Angola
Mistakes cannot be regarded as signs of failure, on the contrary, they make part of the learning process. Some mistakes show that learners have learned some grammar rules. For example if a students says "goed" instead of "went", it shows that he or she has learned the ed past form but the student has over generalised the rule and some remedial lessons are needed. Correcting every mistake may inhibit learners from participating enthusiastically in the lessons, specially in communicative activities.

Patricia Plaza
I'm very interested in the topic of errors in writing because I'm currently doing research on a related isssue. I personally think that students make more and more mistakes in written English because of the treatment that error has been given. The new treatment of error states that errors do not impede communication , and therefore they should not be corrected but rather considered to be part of the learning process. In my opinion, errors may not interfere with face-to-face social interaction, where non-linguistic features and self-correction contribute to the trasnmission of the message. However, they do prevent messages from getting across in written communication. I'd like to share this opinion and get some comments back, if possible.

Val F-G
I think it depends on the student and on the teacher's insight. One of my students insists that I correct all her written mistakes, however, I feel this may undermine the confidence of other students. A page full of corrections can be quite daunting to say the least.
I find it helps for the student to read out their own writing. They can often spot errors themselves if it doesn't sound 'right'.

Jill
I try to correct most of the written mistakes but not necessarily all at the same time, it depends on how many or how serious they are. However, before talking about mistakes, I like to point out how well the students have done and praise their achievements. Then I would move onto the less good parts and discuss together what improvements could be made and the reasons behind them. If the aim is to communicate effectively orally, I think the ability to communicate, even with some errors, is far more important than becoming tongue-tied and obsessed with grammatical correctness.

Astrid Sköldebring, Sweden
As of this school year I have begun using the "Portfolio-system" with my English classes. After realizing that very few students actually go back to their old written assignments and check up on the corrections (that took me hours to do!) I decided that my efforts were mostly futile. If they do check up, it´s still basically just a passive exercise. Instead, I usually turn the exercise into an active one by underlining the errors (perhaps referring to the error in the margin with a v for verb-error, n for noun, and so on) and have the students suggest alternatives themselves. This means in effect that they re-write the assignment, and I feel they benefit from this procedure as they put in an extra effort the second time.

James Stilwell-Stronge, Spain
I think it essential to correct and explain all errors in written work. Less so in spoken.
There are many ways of doing the explanation part, ranging from direct teacher-student explanation to peer "try-to-find-the-rule" type of exercise.
What I really cannot accept is that so many course books include error correction exercises from very early stages.
Students mentally record what is written. They spend minutes looking at and mentally repeating an incorrect sentence, and only one second on the correct version: it only produces confusion and ingrains the error in the student mind.

Nina Koptyug
I would divide Error Correction into several sections, according to Age, Level, Type of Task, to begin with.
1) Age. If your students are quite young, it is very important not to interrupt them at all when they speak a foreign language. They make mistakes in their own language, too. After they all had their say, I'd work at the mistakes which most or all of them make, and also give individual cards to each student. For example, there is no ARTICLE in Russian, nor is there a link verb in the present tense, and there are no auxiliary verbs in questions. "I am a student" becomes "I student", "Do you like it?" becomes "Like it?", and so on. Try to explain to young students what "do" means in a question, why they should use the mysterious word "a" in front of some nouns, but not all of them, and you'll see the difficulty. One should tread this ground with great caution, so as not to discourage the students.
2) Level. When we can already speak about a level, we can introduce some Golden Rules in the beginning of a theme. I usually have them handy so that if a student makes a mistake, I can simply point at them, to have my class chorus a correction.
3) Type of Task. If it is reading aloud, for instance, corrections can be made at once. If a student is making a report, I resort to jotting down the mistakes on a card which I then give to the said student, and they ask questions later if they wish.

Galina Kavaliauskiene, Lithuania
In my opinion, learner self-correction is more important than teacher's correction, because learners have time to THINK about their errors.
With teacher's correction, students more worry about their grade (mark), but not about improving their performance in the future.
Although I voted for correcting some mistakes, what I really support is just underlining learners' errors in their written work and ask them to self-correct (either in pairs or individually, if they prefer individual self-correction. You know, how learners are intimidated by losing face). Teacher's role is to provide feedback and answer any questions that learners might have.

Gill, Ghana
I haven't voted yet. I thought I would see what the comments were first because the choices for voting seem a bit ambiguous. By "correct" do you mean "draw attention to an error" or "draw attention to the error and give a correct alternative". I usually do the first for all mistakes, depending on the time that will be available for discussing the alternatives/correct answers. If there is very little time for discussion I will give answers or strong hints so that the student will hopefully understand where they went wrong.
Looking forward to reading other comments.