Those who can do, those who can't teach and those who have been at the school longer than you, or are drinking buddies of the Head Teacher, appraise teachers.
Usually you will be given a fair (meaning anywhere between a week and 6 minutes) amount of warning that you won't be able to fall back on your favourite wordsearch for the umpteenth time and will have to produce something that bears more than a passing resemblance to a lesson plan.
Many teachers fail to give the humble lesson plan its due. Think of it as educational Viagra for learning. Imagine you've just had three consecutive private sessions and are feeling emotionally and physically drained. You're not a machine, you can't just turn it on for the big group session you've got planned at the end of the day. You need an artificial boost so as not to let your audience down and to ensure that they participate fully. That's where the much maligned lesson plan comes to the rescue.
The ‘Senior Teacher', will nod and "Hmmm" whilst casting a knowing eye over the ersatz educational waffle that you've cobbled together in your lesson plan. You, on the other hand, will be wiping sweaty palms on your newly pressed slacks - something you'll regret later when the stains on your trousers become a major distraction to the class.
Never had to do a lesson plan? Don't believe the hype - there are actually only 6 different lesson plans in existence - all others are variations of these. Basically, they all begin with an ‘Aim'.
Briefly your aim shouldn't solely be along the lines of getting through the lesson without getting caught peering down the blouse of the babe from Accounts. Try to attain the nirvana of one line descriptive ‘Aim' sentences by using words like ‘lexis' and ‘facilitate' and ‘syntax'. Your goal is something along the lines of:
"Aim : To facilitate constructive syntax using appropriate L2 lexis."
This has absolutely no meaning but it's often enough to impress all but the most knowledgeable assessors - try it for yourself.
Start the lesson by using a tried and tested ‘Warmer' - this is the accepted TEFL terminology for an activity designed to lull the students into believing that they will be spending the next 90 minutes in a ‘sanuk' work free environment. Class discussions on the relative merits of Man U & Liverpool, MBK & Central, Siemens & Nokia, or any of the other major talking points that crop up without prompting in the average classroom, always make good warmers. Note that at least 25% of this activity should be conducted in English. Allowing the warmer to drag on until the mid lesson break will be frowned upon.
‘Presentation' follows - this is where the teacher gets the chance to confuse the students by waffling on about a random grammar point which will later be proved to be an exception rather than the rule. Any detailed explanations should be accompanied by semi-illegible scrawling on the white board which can easily be wiped off before the students have time to question its validity.
Having spent 10 minutes writing something that they will never read again in their pristine Hello Kitty notebooks, it's time for some ‘Practice'. Practice generally comes in two forms: ‘guided' and ‘free'. Guided = the teacher tells them what to say. Free = the students talk about whatever they like and the teacher is happy because at least they're speaking an approximation to English.
Now that they've mastered whatever it is they were supposed to be learning it's ‘Production' time. The attentive students now have 20 minutes to whisper amongst themselves and stare blankly at each other before one plucks up the courage to ask just what they are supposed to be doing. The teacher now has 5 minutes to recap the entire lesson before the assembled students release a collective, knowing, " Ohhhhhh" which is followed by more incomprehensible muttering and finally by the most intelligent learner spending the next 10 minutes translating the entire lesson into Thai which then draws another "Ohhhhhh" of understanding. If there's any time left after this labourious ritual then it's the teacher's job to get the students on their feet to ‘mingle' or ‘mill' - technical parlance for wandering aimlessly around chatting.
End the class by allotting a few minutes for any questions the students might have e.g. " Will this be in the exam?" which could be more accurately expressed as " Is there any point in me committing any of this to memory or can I delete the last 2 hours from my short-term memory?". This in turn equates to " I'm pretty sure my brain's full so if you make me remember this then I'll have to erase my entire childhood memories."
Finally, a word of warning, just as your on the way out of the door, there will always be a question along the lines of "Do we have to bring our dictionaries next lesson?". Resist the urge to remind the class that there are an unimaginably large number of words in the English language and the class collectively knows 426 of them - which effectively negates any possibility of attaining a TOEFL / TOEIC / IELTS or even IQ score in treble figures.