... and how to exploit the advantages and avoid the disadvantages
Few skills that TEFL teachers learn seem more unnatural when you first do it and then more difficult to drop once you have developed the habit than eliciting- trying to get all the language and other answers from the students before you finally give them the solution. There are advantages and disadvantages to eliciting, and looking at these should help both the beginning teacher who hasn't picked up the skill yet and the experienced teacher who has started to use it automatically without thinking about when and how they should do so.
Even the best students will find their minds wandering occasionally if there is someone at the front of the room speaking, especially if what is being said is a grammar explanation in a foreign language. If they are contributing to that stage of the lesson or at least know that they could be called upon at any time, there is far less chance that a missing item on their shopping list or something that their ex-girlfriend said to them could drift into their minds. Ways of exploiting this include choosing people at random rather than just going along the row and mixing this up with giving a general question for the whole class to shout out their answers to. You can combine these by taking the suggestion of one student and asking the whole class if they agree or having anything to add.
Eliciting helps you realise if the students are listening and understanding or not
If you say "The Present Perfect is used to talk about things connecting the present and the past", there is no way at that stage of knowing if the students have understood what you said (even if they were listening!) If you say "What do these Present Perfect sentences have in common?" or "What's the difference between these Simple Past and Present Perfect sentences?" instead, a lack of an answer makes it likely that they are not listening or are not following you (but see below for other possible reasons), and a correct answer makes it clear that they are alert and with you in your explanation. If that answer has only come from one person, you will need to make sure everyone else has understood as well with concept checking questions or further elicitation of example sentences etc.
Eliciting helps you find out what they already know
By starting with easy questions and working your way towards more difficult ones, you will be able to boost their confidence with the first ones and realise the limits of their knowledge once their answers start to become incomplete or wrong. Finding out what students do and don't know will also help you spend lesson time on the most important things, and help you plan future lessons with that in mind. There is the danger that you will only find out the limits of the knowledge of some of the students, or that you will underestimate their knowledge because they know but are not saying or they know but haven't explained themselves well. You can partly overcome these problems by monitoring body language and making sure everyone speaks.
Elicitation can mean more student talking time (STT)/ cut down on teacher talking time (TTT)
The fact that students are responding to almost everything you say in almost every stage of the lesson should mean that they are speaking more often than they would be if they just listening to an explanation by the teacher. This effect can be increased if you can get them commenting on what the other students say in the eliciting stages. Choosing your questions carefully can also help, e.g. by using Wh- questions rather than Yes/ No questions and by asking questions that have many different correct answers ("Open questions") rather than ones where you are just looking for one particular answer. This last tip should also cut down on your speaking time by meaning that you don't have to say "Good, but I was looking for a different word. What do you call...?" One example of this is to brainstorm all the vocabulary they know in a particular category rather than just defining the one piece of vocabulary you are looking for. Another is to ask "What does the Second Conditional mean?" rather than "Is the Second Conditional used to talk about real things?"
Eliciting helps students learn how to guess
Communicating in real time is a continual process of guessing- trying to predict what people are going to say, trying to work out their attitude by their tone of voice and body language, etc etc. Many students lack this skill or are shy about using it in the foreign language classroom, and getting them used to guessing the answer to almost everything you say by eliciting can really help with this. To make sure they are happy to make a guess when you are eliciting, you'll need to give positive feedback for any kind of contribution ("Very imaginative, but I meant something a bit more everyday"), standing close to people with quiet voices when they answer so that they don't misinterpret not hearing them as lack of understanding, and asking questions that have many possible correct answers.
They can learn/ be exposed to useful incidental language during elicitation
Incidental language is language that you don't teach but still hope that students pick up during their interactions in the classroom. Phrases they should learn how to understand and then maybe go on to be able to use (or at least be ready to learn consciously when they come up in the syllabus) from elicitation include "What does... mean?" "How do you spell...?" "What is this sound?" and "What's the difference between ... and ...?"
Elicitation can show them how to work things out for themselves
This is really just an aspect of the point above. Telling students that "Obstruction is the noun of obstruct" is obviously quick and might even be listened to and understood, especially if you write it up on the board in some way at the same time. However, there is often a reason to take the time to elicit with "What kind of word is 'action'?... A noun, good. And what word does it come from? I mean, is there a similar word that is an adjective, an adverb, a verb etc that is similar? Try taking off some of the letters towards the end... 'Act', good! What kind of verb is 'act'? We say 'He is acting', so what kind of word is it in that sentence?... 'V'. Sure, that's right, that's what it says in your dictionary. 'V' stands for 'verb'. So, 'act' is the verb and 'action' is the noun. Okay, so let's go back to 'obstruct' and 'obstruction.'..." This is a rather long example but I believe even this could be worthwhile because it has taught students some useful grammatical terminology and, more importantly, shown them how to analyse word formation for themselves.
As the example above shows, sometimes eliciting a word or explanation can take ten times as long as just explaining it. If students are getting more speaking during that time and are learning useful language analysis skills and incidental language this doesn't have to be a reason to abandon it, but it can still mean that students have forgotten about what the listening is supposed to be about (therefore making your lovely lead in stage a waste of time) by the time the vocabulary pre-teach finishes. Ways of avoiding this problem include: plan your elicitation and make sure you have found the quickest way, use pictures and other prompts if that will cut down on the amount of time eliciting will take, and teach them the grammatical jargon etc that they will need to understand when you are eliciting (maybe dedicating a whole section of a lesson to it). If how long your elicitation is taking is simply a sign of you not having got the hang of the process yet, you could try eliciting the same language from a teacher before your lesson to practice and get feedback, using Elementary Learner's dictionary definitions to cut down on the length and complexity of your own explanations, doing something similar with grammar explanations from grammar books for students, or giving students the vocabulary list for the next lesson to learn on their own the evening before. Alternatively, give written eliciting stages, e.g. definitions of the vocabulary you want to teach them (maybe letting them use bilingual dictionaries or giving them a list of the vocabulary to match to the definitions) or guided discovery grammar tasks.
Eliciting doesn't always lead to more STT
If the elicitation is much longer than the thing you are trying to elicit, it can actually mean more TTT than if you had just given them the answer. A general rule is to make the question shorter than the answers (using the tips elsewhere in this article). If that is impossible, explaining might be better than eliciting at that stage.
One student can dominate answering your elicitation questions
Solutions include: nominate particular people to answer, give them the elicitation stage written down to go through with a partner, follow all their answers up with requests for additional ideas from the other students, or occasionally tell them that you'd like someone else to answer.
Elicitation can become automatic
This is one of the most heard complaints from people attending workshops for teachers- the person giving the workshop isn't able to drop their classroom manner and so spends the whole time eliciting the things the teachers attending already know and doesn't give the kind of new information that they expected to hear. A good general tip for having balance in your classes is: once you know how to do something, try switching to something else. In this case, that means that once you are able to elicit example sentences, pieces of vocabulary and grammatical explanations almost at will, you are ready to look at what the other options could be at each stage. Some options are: give a mini-presentation as preparation for them giving their own mini-presentations on future language points, get them to do the guided discovery activities from the worksheet or textbook in groups, and get them into the habit of asking you for explanation by teaching them typical classroom questions ("What does ... mean?" etc) and giving them tasks that are impossible if they didn't take advantage of the Q and A stage.
Eliciting can be met by silence
This could mean that students don't know the answer, that they do know the answer but aren't confident, that they would know the answer but haven't understood your elicitation, that the people who do know the answer are too shy to speak, that the person who knows the answer is trying to avoid dominating the class, that giving the right answer before everyone else might seem like boasting, that they have been put off answering by getting so many previous answers wrong, that they know you always give the answer if they wait long enough, that they expect to be asked individually, that they don't understand that you really want people to speak out, or even that they are refusing to take part because they are unhappy with the teaching methodology of the teacher. Knowing how to reduce the problem of silence depends firstly on you being able to identify which of these reasons is the most important for your class or a particular student.
The language of elicitation is not like normal communication
Can you imagine elicitation in normal life? "What do you want from the shops?" "What do you think I want from the shops? They are white and sold in packets..." That would soon lead to a divorce, I reckon! That does not necessarily mean it should be avoided (after all, the phonemic script isn't less useful for EFL students just because it isn't used by native speakers), but making classroom language as natural as possible will help with giving them exposure to the kinds of language they are likely to meet in their real lives. One way you can work on this is to brainstorm all the sentences you could use when eliciting and choose the ones that are most natural. Questions types that are perfectly natural in native speaker classrooms but are sometimes neglected in EFL classrooms include statements with tag questions, statements as questions (just changing the intonation), unfinished sentences ("And the opposite of 'hot' is...?") and leaving out some grammar words such as pronouns.
Eliciting can get boring/ repetitive
As well as mixing up elicitation with the other techniques like guided discovery worksheets that are recommended elsewhere in this article, you can introduce variety by using different methods of elicitation (pictures, realia, sketches, mime, guessing from context etc) and by brainstorming different language you can use to start your sentences ("What do you call I thing for...?" "I'm thinking of a thing that..." "Can anyone tell me the name of...?" "You should all be able to explain the difference between..." "Do you all remember the object we talked about on Monday?" etc).
Eliciting can seem childish/ patronising
One way out of this is to be especially careful with your tone of voice and body language, as "Good guess!" with extreme variation in tone and both thumbs up is likely to make adult students laugh out loud with embarrassment or genuine humour. You could also just go with that by making it so extreme sometimes that it is obvious that you are overdoing it deliberately. Otherwise, I have sometimes found it useful to say to my students that how I speak to them is just "teacher speak" and so useful for me but not necessarily something they should copy. I don't have any other particular ideas to overcome this point and it is something I still find to be an issue in adult classes and even more in teenage classes where they want to be treated as more of an adult than the adults do! Keeping this is mind should at least help the teacher to subconsciously adjust their language.
Eliciting can be culturally inappropriate
Some students are used to the teacher giving all the answers and so do not expect you to be waiting in silence for the students to come up with it. With such students, too much elicitation can lead to a lot of classroom silence and even thoughts that the teacher is not taking responsibility and maybe not even teaching. Some justification of your teaching methods in your classes, in tutorials, or the literature for the school can help, as can questions on feedback questionnaires that seek to analyse students' attitudes to elicitation and the reasons for those feelings. If you are encountering resistance or think you might, starting with a more traditional teaching style and then moving towards students contributing more and more can help. It is possible to give these factors too much importance, however, as students might not be used to elicitation or comfortable about it yet but might have chosen to come to communicative language classes exactly so that they can get used to those kinds of things. There is also a chance that even students who don't answer when you elicit have at least come up with an answer in their heads, and so have prepared their brains to learn whatever you and the other students say.
There is no point asking a question you already know the answer to
This is one factor of the unnaturalness of elicitation questions. Ways around this include asking questions that there are many different ways of answering, brainstorming rather than asking for particular things, and asking students to give example sentences that are actually true about them. The most important thing, though, is to always respond to things they say first of all for their meaning and only after for how much they were what you were looking for, e.g. "Can you give me an example of the Present Perfect that is true for you?" "I have been to Paris last weekend" "Really, just for the weekend? That's a lot of travel. Last weekend is a finished time, though, so if you just change the verb..."
There is a chance the wrong thing will be more memorable than the right one
There is a lot of debate about whether writing something wrong on the board is likely to make them remember it, and I have personal experience in foreign languages of thinking "I remember there are two forms and one of them is right and the other one is wrong, but I can't for the life of me remember which one is which". The way I see it now, though, is that being able to remember there is a tricky point there is at least progress. If students are learning off each other enough that they start picking up each other's mistakes, this is also something I take as proof that an interactive, communicative language classroom where they work cooperatively is working. Some clear error correction should (eventually) sort out any doubts.
The positive feedback might mean that the right answer doesn't stand out
This is linked to the point above- if you are responding to all student suggestions with "Good idea", "Very imaginative", "That's correct English, but not what I was looking for" etc, the right answer might not stick in students' minds, and the fact that it was the right answer might even be completely missed by distracted students. One technique is to give positive feedback to all the contributions but only write the one you were looking for on the board.