Tuesday, 18 August 2009

The quietest lesson

Late last year I was doing a bit of revision of basic averages with a (low-ish ability) class who kept getting confused between mean, median and mode.

The homework for the previous week had a question at the end inviting them to tell me their favourite terrible joke.

We then used these to look at averages in context - i gave them a list of rubbish jokes (obviously pretending i thought they were the funniest things ever...) and they found average number of words per sentence, letters per word etc. Very amusing and a decent reminder of why we divide by the total number of items - letters per word is different from letters per sentence.

We then moved this to look at Stylometry - i gave each group a different writing sample. Group A had an essay written by "Julia" and Group B had an essay written by Aaron. Group C had an essay but didn't know who wrote it...

Yeah, alright you can all see where this is going...

I told them that these two kids handed in the same essay. One of them has obviously copied the other persons work. How are we going to find out who is the cheater?

Suggestion 1 was handwriting- but this was shot down because things are all word processed now. One kid suggested we stick them suspects in an interview room and sweat it out of em a la Homciide:Life on the Street, but i gently weaned him off this idea.

Given what we had just done, lots of kids realised straight away that we could find the average number of words per sentence etc for each piece and use this to compare the "copied" work to other pieces. The person who copied the essay will be the person whose average writing style is nothing like the average writing style of the copied work.

My kids always get involved in things if there is some sort of crime or mystery involved. Basically absolute silence here whilst they collected data, to the point where i started going round and winding kids up cos i was bored. They are either gonna all grow up cops or they're gonna be the most elusive criminals around...