Prior knowledge or prior labels? Two lessons on prior knowledge

Dr Amanda Berry & Mr Paul Ribert Monash University & Simond's Catholic College Clayton & West Melbourne, Victoria, Australia

It was time to teach the topic of human reproductive systems to my year 8 (all boys) classes. Students often come to class thinking that they ‘know it all' about human reproduction (even when they don't!). I wanted to find out what they did know and hopefully help them to sort out some differences between their ‘everyday knowledge' and accepted scientific knowledge. I had been exploring students' prior views in other science topics and I thought that this new topic of reproduction was a good one to continue this approach. After all, they were more than likely to have some prior views about reproduction! I had some other learning objectives with this class, too. These were to encourage students' skills in questioning, develop cooperation amongst peers, improve their skills of presenting to the class and encouraging them to feel comfortable using correct science terminology.

In the first of my two year 8 classes, I started off investigating students' prior views by handing out to each student an unlabelled diagram (cross section) of the human male and female reproductive system. I asked students to write in the missing labels and to include the functions of any of the labeled parts, if they knew them. I emphasised that the point of the activity was not about using reference material ‘to get the right answers' (some of my students really worry about this) but to explore what they already knew, so that we could have a better sense of where the unit might go and what difficulties/confusions they may have.

After I handed out the task, there was some initial confusion about what to do, then most students set to work labeling the diagrams. I could see that nearly all of them could label at least one or two things and they quickly began sharing their ideas with those around them and filling in any missing gaps. I then divided the class into five groups and asked each group to pool its knowledge, so that all students could finish filling out the diagram. I also supplied them with a word list that included a range of terms, from readily recognisable (e.g. penis, testicles) to more sophisticated (for example, fallopian tubes, epididymus) that I asked them to check off the ones they had included.

It was while I was walking around watching the groups at work that I began to realise some problems with the approach I had chosen; problems I hadn't thought about before. While students could label some of the ‘obvious' parts of each diagram, they were completely confused about other parts of the diagram, as well as some of the terms that I had given them.

‘What's that sir?' one group asked me.

‘Have you got any ideas about what it might be?' I asked.

‘Not really', came the response.

‘It's got something to do with the passage of waste material from the body', I suggested.

‘What? What's that got to do with the reproductive system?'

Another asked, ‘What's the pelvic bone?'

And ‘What about that thing there? What's that?' (this student was pointing to the spinal column).

‘Hmm...yes', I muttered. ‘Don't worry, some of these parts are a bit harder to label than others. Just do what you can.'

As I looked again at these diagrams, I started to see some of the possible difficulties associated with them. There were structures such as the colon and the pelvic bone that are not usually thought of in everyday knowledge as part of the reproductive system but that are regularly included on diagrams of this type. I had not really thought about this before and why it might be confusing to students doing a task about the reproductive system. Also, the shape of some of the parts were ‘stylised' representations, and pretty hard to interpret from the squiggles on the page. I started to think that maybe this wasn't so much an exercise in reviewing prior knowledge as I had hoped but more about students' ability to pick the correct labels or interpret the diagram.

I asked each group to present their work-in-progress to the class, then students went back to their desks. Individually, they looked at the information from the textbook and other worksheets and figured out what mistakes they made. They regrouped and discussed these, then each group re-presented their findings to the class. All the while I was thinking about whether this activity was really achieving what I had intended.

These thoughts were going through my head as the bell sounded and my second year 8 class was entering the room. Okay, I had planned to do the same thing with this class, but maybe I needed to make changes. I took a deep breath and thought about what I could do that would really get at the prior knowledge I was after. I had an idea. It was a bit risky but I figured that it was worth a try. I took out a packet of A3 poster paper.

‘Okay guys, today, as I mentioned to you, we are starting off our topic of male and female reproductive systems' (muffled laughter, groans, some smiles and nods).

‘To get started, I thought it would be helpful to find out something about what you already know about this topic' (more muffled laughter).

‘Oh we know everything sir! What do you need to know?'

‘What I'd like you to do is draw one picture of the human male reproductive system, and one picture of a female human reproductive system. Label the names of any parts you know and where you can, write the function of the parts you have labeled.'

I passed around the A3 sheets of paper, then encouraged them to get to work. I felt pretty nervous about doing this - drawing a labeled diagram of the reproductive system could be an invitation to engage in some inappropriate responses to the task. At the same time, I knew this group of boys well and I figured that, after some kidding around, they would do what I had asked.

‘You're joking!' was one response. ‘I have no idea what to draw!' was another. ‘Just have a go', I encouraged them.

After a little time, most of the class were on task, and they even seemed to be quite enjoying it! As I listened to their conversations this time, they were a little different from what I had heard in the other year 8 class. This group seemed to be taking more ownership and interest in what they were doing. Instead of doing a labeling task, they were trying to figure out what to draw, how to draw it and what else (besides the obvious) they could include. I could see from their drawings that a number of them were not thinking about the reproductive system as having any internal structures (what was on the outside was all there was) - particularly for the male. I tried to get them to think about this as I walked around talking with them about their pictures. Some students, on the other hand, drew very detailed anatomically correct diagrams.

I asked them about it. ‘Learnt it in primary school, sir.' This made me think about the range of knowledge that they had. Last class, I hadn't thought so much about that, because it was more about knowing, or not knowing, the labels.

Similar to the last class, I asked students to pool their information in groups but this time, to produce one drawing from the group that showed the group's collective knowledge. Their conversations were animated as they argued about what the drawing should look like and what should be included. I gave them the list of terms again, too.

‘Here is a list of words that are commonly used when studying the reproductive system. Do you have any of these on your diagram?'

Students presented their group drawings to the class and some explained the different structures they had included.

Afterwards, I asked them to have a look in their texts to compare the diagrams they drew with the ones in the book. The lesson ended as they were doing this - somehow the time had gone much more quickly during than the first session, where we had easily completed this task. Perhaps there was something here about giving them more time to explore their ideas?

I learnt a few things as a result of these two lessons in investigating students' prior knowledge:

The first class seemed to have less ownership on the work they did and what they presented to the class. The quality of the learning seemed to be less, although the amount of time taken to complete the lesson was considerably reduced. When the students in the second class went back to their desks to figure out what mistakes they had made, they had to re-draw their diagrams and add things they had missed. They could see the things they were not sure about and how they fitted into their diagram.

The two different lessons provided two unique tests of prior knowledge. In the first, they concentrated on trying to figure out labels. In the second, they were challenged to a much greater extent to have no reference material to start with. Although individually they found this challenging, collectively as a group of five, they produced some excellent work.

The students were asked what they found to be of value in the lesson.

‘It was actually fun', one boy said.

Many new things were discovered because the boys felt the pressure of having to present to the class, even though they were not sure if they were correct.

‘Because they had to discuss the mistakes they had made with the class, we remembered the function of many of the more difficult structures.'

Overall, they found it to be more valuable than just being given labeled diagrams and being asked to memorise where everything fitted in and what function it had.

The next week the students were at camp. The following week it was amazing to see how much knowledge the class that had drawn their own diagrams had retained. They still had their own pictures.

‘Sir, what do we do with our pictures? I'm not too sure if my parents will be happy to see this in my book!'

The lessons were reversed, the second class was easily able to fill in the diagrams with the labels and explain the function, whereas the first class simply could not remember. They required far more prompting. Here was another very valuable lesson for me regarding students' ownership of work and effective learning.

*This paper was written by Paul Ribet, in collaboration with Dr Amanda Berry.