Thursday, 24 November 2011





5000 WORDS

Biology – GCSE level.

The creation-evolution controversy, particularly its place in the classroom, is undoubtedly a hot topic du jour. Contemporary reaction to Darwin’s theory of evolution was in many ways less critical than that of today. A post-First World War surge of opposition to the idea of evolution, culminating in the Scopes monkey trial, has led to creationism (latterly in the guise of intelligent design) being taught for decades in US schools. The level of scientific support for evolution is overwhelming, but still the debate rages.

The idea that humans evolved from monkeys (or monkeys from fish) is a common misconception of Darwin’s theory, which actually proposes that humans and monkeys share a common ancestor that lived about 40 million years ago. It is also wrong to state that Darwin believed that humans evolved from monkeys via Glen (presumably the ‘missing link’ so beloved of creationists). A number of transitional fossils have been found to support the hominid evolutionary record, including Lucy (Australopithecus afarensi) and Ardi (Ardipithecus ramidus), but as yet there is no Glen. Such a discovery would surely only weaken the creationists’ standpoint.

The decision by the Kansas State Board of Education to allow the teaching of intelligent design as an alternative to evolution was challenged by concerned citizen Bobby Henderson, who called for Flying Spaghetti Monsterism, his belief in a supernatural creator that closely resembles spaghetti and meatballs, to also be allotted equal time in science classrooms. The idea of a parody religion is not new – Bertrand Russell’s celestial teapot is the most famous argument that the philosophic burden of proof lies upon those who make unfalsifiable claims, not on those who reject them. Calls have also been made for physics teachers, alongside Newton’s law of universal gravitation, to teach intelligent falling. President Bush endorsed the teaching of intelligent design alongside evolution, stating, "I felt like both sides ought to be properly taught … so people can understand what the debate is about.” This is apt when he is perhaps the closest thing to a missing link yet found.

If creationism is to be taught in schools, then it should not be in the science classroom, but as a separate subject of politics of science and religion. And it should certainly be more balanced than simply calling Darwin a crackpot. Charles Darwin is one of the most influential figures in human history, and has the ultimate accolade of appearing on the back of an English banknote. What next: Elizabeth Fry = wally? Boulton and Watt = bozos? Adam Smith = nincompoop? (His name has been appropriated by the Adam Smith Institute, responsible for recommending the privatisation of British Rail and the introduction of the Poll Tax, so maybe the jury should stay out on that one.)

A ‘WO’ has been inserted in front of ‘MAN’, pointing out that the gender-neutral ‘human’ should perhaps have been used (despite the original use of ‘man’ as being a gender-neutral indefinite pronoun). Whilst this kind of direct linguistic rejection of a patriarchal hegemony might seem a little ‘bra-burning wimmin’ now, it provides a welcome relief to all the other conservative, reactionary nonsense.

A 5000 word essay by what is presumably this Friday is a tall order, but if God made the world in six days then it should be doable.

0/10 See me.

(Many thanks to Wayne for sending this picture in.)

Thursday, 10 November 2011



X| | 
 | |O

Lessons in Life – universal
Computer Science – A-level/undergraduate level

There can be few better exhortations to students than this. Working hard and doing one’s best will always produce the finest possible results, either in the classroom or on the playing field. After any exam or sporting challenge there is no failure if one can say afterwards “I did my best”. (England footballers please take note.)

A game of noughts and crosses is underway on the blackboard. If this has been done by a student then it should have been rubbed off immediately (see post #9 re Wilson and Kelling’s broken windows theory). But if this is actually part of the lesson then a gold star should be awarded as noughts and crosses is a great introduction to many mathematical and computer science concepts from combinations and symmetry to artificial intelligence.

A first question to pose to the class would be how many games of noughts and crosses are possible (the game tree size)? A naive answer would be 9! = 362,880 (assuming X always goes first). However, many games will be over before all the squares are filled, and many more are simply rotations and reflections of others (in effect there are not nine, but only three starting places: corner, centre and edge). Taking these into account gives an answer of 26,830.

Devising an algorithm to produce perfect play is also a favourite challenge, exploring ideas such as backwards reasoning and recursion. These can then be applied to other, more complex games such as Connect 4 and draughts, through to unsolved games such as Reversi, chess and Go (with its game tree complexity of 10360).

However, if this is an attempt to teach the strategy of perfect play then one must hope that the teacher has picked a very poorly-played game to illustrate what not to do. Assuming that X’s first move was in the corner (always the best start: of the then 73 possible games, assuming perfect play on X’s part, 71 result in victory and two in a draw), then O has immediately blundered by playing the far edge instead of the centre (where his/her only hope of a draw can come from), resulting in what should be certain victory for X. X could then force a win by playing the centre, but has him/herself blundered by playing middle bottom. O can now snatch a draw from the jaws of defeat by playing centre or top right, leaving X to harp on about how the Wags should have been allowed to stay in the team hotel.

Despites its pedagogical pedigree, noughts and crosses quickly becomes futile when both players can easily force a draw. This was well-illustrated in WarGames, when the military supercomputer, equating the game to global thermonuclear war, evaluated all possible outcomes and remarked, “Strange game. The only winning move is not to play.” Failing that, just work hard and do your best.

8/10 An inspired choice of teaching material.

Monday, 31 October 2011


Dr Lagina’s Math tutorial

√24/√3 = √(24/3) = √8

= √(4.2) = √4√2 = 2√2

√(81/25) = √81/√25 = 9/5


Bramm S
Blake F
Hailey Y
Jordan A
Kara B

Mathematics – A-level standard.

These are some good examples of operations with surds, using the rules for both multiplication (n√(a.b) = n√a.n√b) and division (n√(a/b) = n√a/n√b). All the working is correct. The sloppy square root sign in the second example extending over the equals sign could be confusing, and handwriting in general isn’t great, but is legible.

Unfortunately, despite this good academic work, Dr Lagina is entirely unsuited to a career in education due to his surname. It would be no use trying to insist on a different pronunciation such as La-GHEE-na as students of any age will still make cruel remarks – it is little wonder that his detention list is so long. It is a shame that no careers officer ever tried to dissuade him from his current employment path, though he is still young enough to change his vocation. It is either that or change his name: even a teacher should be able to afford the £33 fee for a Deed Poll, though perhaps he has already changed it from something even more embarrassing, like Dr Lesticle, Dr Lyphilis or Nick Clegg.

There are a couple of other points to make. Firstly, a different hand has scrawled MOZ on the blackboard. According to Wilson and Kelling’s broken windows theory, a disordered environment signals a place where people do as they please and get away with it without being detected. Like the New York City Transit Authority removing graffiti from their trains leading to a sudden and significant drop in petty and serious crime, this should have been wiped off before the lesson began in a zero-tolerance approach. Not restoring a disordered environment early means that classroom discipline will only deteriorate, a fact surely worsened when one’s surname rhymes with a part of the female genitals. Whether Moz is the Morty who appears on the detention list, or just a deranged Morrissey fan is not clear.

Secondly, the appearance of Bramm S on the detention list raises the questions of how many students with this unusual name there are in this class that they need to be differentiated by their surnames, and whether this is a class consisting entirely of Gothic novelists, though there is no sign of Mary S or Edgar A P, and the works of Jordan A and Kara B must have been sadly lost to the world of literature.

8/10 – Good work, though loses a mark for ‘math’. And remember that sticks and stones may break your bones, but being called Dr Vagina every day of your working life will never hurt you. Though it may cause a career-ending nervous breakdown.

(Many thanks to Wim for sending this picture in.)

Saturday, 15 October 2011

Break Time!

Just to say that there will be a short break from lessons whilst we at Blackboards in Porn Towers stop looking at pornography for long enough to move to bigger premises. In the meantime, please do browse the archives.

Thank you to everyone for your comments and for sending in so many great images of blackboards in porn. We have been deluged with a shedload* of pornography, but hope to get through the backlog and posting reports again soon. It's a tough job, but somebody has to do it.

(* The SI unit of pornography)

Thursday, 13 October 2011


Mary Had A Little Lamb

- ½ beat
- 1 beat
- 2 beats

Music – introductory level

The treble clefs have been beautifully drawn, but there is no hiding some fundamental errors on this blackboard.

Firstly, the time signature is written as both ‘4/4’ and ‘c’. This is tautologous as ‘c’ means common time (4/4), so just one of these will do. Also, there is no need to put the time signature on every line unless it has changed, and there are definitely no mixed meters in Mary Had a Little Lamb.

There is a good attempt at an explanation of the different lengths of notes, though there are actually no quavers in this particular piece, so the teacher might be introducing the concept too early. The dotted minim might not be necessary either, and it is unclear what the minim with a quaver flag is meant to be. The teacher should also draw a semibreve for the last note ('snow').

The biggest error, however, is that each stave has only four lines instead of five. This would make it very difficult for the students to know which notes to play. Reading from the bottom, the first notes would be B A G A | B B B, which sounds correct. But reading from the top, the notes would be D C B C | D D D, which sounds wrong as there is only a semitone between the second and third notes. Imagine if half the class were playing one version and the other half the other – it would sound terrible and the class’s confidence might be badly affected if they felt they couldn’t master even this simple melody. (To be honest, when teaching this level of music it inevitably sounds awful when played tutti, so the teacher really isn’t doing his ears any favours here.)

An experienced musician would see that the positioning of the treble clef tells us which line is G (hence its alternative name of the G-clef), but it is unlikely that students of this level would know that. After adding the missing line to the top of the stave, the tune itself is basically correct, though usually the last two notes of bar four go up (to D in this case). The fact that the last note is a G helps to indicate that this version is in the key of G so needs a # sign on the F line just after the treble clef.

A good mnemonic for remembering the notes on the treble clef is, reading from the bottom line, Every Good Boy Deserves Football. Or, perhaps in the case of this classroom, Flagellation.

5/10 A good effort, marred by a silly error.

(Many thanks to Lucy for sending this picture in.)

Monday, 10 October 2011


1. S=0 A=0
2. S=1/4 A=1/16
3. S=1/2 A=1/4
4. S=1 A=1
5. S=2 A=4
6. S=3 A=9

t p
3/4 02/5
S 42/A9

Mathematics - year 8 level

This sets out to be a good illustration of the function more commonly expressed as y=x2. (Why the teacher has chosen A and S is unclear; these are sometimes used in lower case form as acceleration and distance respectively, but the relationship between them would not then be physically correct.) The important points (S=0, S=1, two points where S<1 and two points where S>1) have been well chosen to illustrate this function, though it would have been useful to have included some more points where S<0 to show what happens when squaring a negative number.

The graph has then been plotted, but sadly this is where the lesson begins to falter. Firstly, axes on the graph should be labelled with 'S' (horizontal) and 'A' (vertical). And the graph that has actually been plotted seems to be more like:
1. S=0 A=4
2. S=4 A=8
3. S=6 A=15

The graph is roughly the correct shape, but is not positioned correctly: it clearly intersects with the vertical axis at A=4. Even allowing for other drawing errors, this is a function more like A=bS2+4. It would also have been useful to extend the graph to S<0.

What is going on on the right-hand blackboard is less clear. There is a drawing of a trapezium, and also the equation 100=S=A, which is hopefully not meant to be related to the function A=S2.

Finally, the teacher should make sure that her students keep their focus on their work. She only has three students, so can't complain too much about the pupil-teacher ratio. The teacher is giving all her attention to the lone male student, allowing the two female students to talk to each other, thus reinforcing gender stereotypes of women in maths, despite being female herself. Sadly, it is this kind of attitude which leads to the 'Math class is tough' talking Barbie and low numbers of women choosing to study maths in further and higher education.

5/10 Shows some promise

(Many thanks to Chris for sending this picture in. Please keep them coming, folks.)

Friday, 2 September 2011





H2O + H2OSO4


H2SO4 => SO4

H2OSO4 = H

Chemistry – A-level/undergraduate level

This is a frustratingly inconsistent approach to writing chemical formulae. On the one hand the teacher has gone to the trouble of also using structural formulae to improve clarity (eg H2N2O2 could be nitramide, but the addition of HO-N=N-OH makes it clear that we are dealing with hyponitrous acid here), but then writes SI (sulphur iodine) instead of Si (silicon) in the formula for orthosilicic acid. This, combined with not using subscripts for many of the numbers, could lead to a great deal of confusion.

Whilst this lesson appears to be aimed at quite a high level, such elementary errors may affect comprehension.

5/10 - rather sloppy.