My S3 credit class have just finished the straight line topic, so today I used the activity from this teacher's tv video as an end-of-topic assessment. I expect this will be familiar to many maths teachers - our probationer used it during one of her student placements last year.
I put the class into groups of two and threes, handed them out the envelopes and said "this is an assessment activity - show me what you have learned in this topic".
The pupils struggled initially with the open nature of the task. Several asked "what are we supposed to do?" to which I replied "show me what you have learned about straight lines." "This is weird" said one of the pupils!
I did not say that they had to make a poster, but the resources to do so were available unobtrusively at the front of the room. Once one group asked if they could make a poster, and I said that they could if they wanted, the idea took off across the room and they all ended up doing so.
Despite my assertions to the contrary, most of the class seemed to believe initially that there was a "right answer" towards which they were heading, and one group of boys said "we've finished" once they had gathered the resources into groups and stuck them onto a poster. I asked if they felt that they had had the opportunity to demonstrate everything that they had learned about straight lines, and they said yes [slightly worrying since we spent some time working on mathematical modelling with straight lines!].
For me the most valuable element of this activity is the discussions that take place between pupils, and between me and the pupils. Pupils have the time to talk to each other about their learning, and these conversations can clear up lots of wee misunderstandings. I am also able to ask interesting questions, and pupils have the time to think about them. I asked one pair of girls, who were busy gathering bits of card into groups: "why does this graph belong with the equation y=6-x?" They answered in terms of gradients and y-intercepts, but were also, when pushed, able to explain that the line represents all the places on the diagram where the equation is true." I asked if this was the only place they could put (3,3) then left to talk to another group. This is the poster they produced:
At the end of the lesson we discussed the activity. The pupils were all very positive about it. One of the boys who had declared "we're finished" said that he would have liked to have had more blank graphs to fill out. I finished by saying "I know this was an assessment activity, but does anyone feel that they have learned some more about straight lines during this lesson?" 80% of the class put their hands up.
Two of my department came in during the lesson to join in with the task of questioning the pupils. At the end of the day we had a chat with two more members of the department about how we might improve the activity. We thought we would try to make the resources reusable (laminated perhaps so pupils can write on them with dry-wipe pens), or maybe make it into an electronic activity by having the resources as objects on a drawing. We would also change the cards to make the task more open-ended. At the moment they fit together too neatly, so it does seem as though there is one right answer.