• 12-15

This activity is ongoing and hopefully will lead the students towards a more organised approach to any investigation and analysis and a deeper understanding of their own thought processes.

The idea is that rather than teach, in a traditional manner, the 7 step scientific method, it can be allowed to evolve as students go through several science investigations.

Began with pre-assessment.

Asked students to write out all the steps involved in a science investigation. They were reminded that there are no wrong answers (you need to do this a lot) and that the idea is to understand how our individual minds work when approaching a problem.

The result was that each student produced a map or list of steps they would see themselves following in a science experiment. These were very different, as individual as the students themselves. I was surprised and pleased to have such variety in a class of 12. There were instruction lists, linear step-by-step models, expanding options list, centralised mind-maps and a cartoon map (I will try to upload scanned versions at some point).

We all then reviewed the others' steps and commented on them. This was an interesting discussion. The students really saw and understood that they each have very different ways of going through a problem. The students also decided that certain pairs might find it especially hard to work together because their natural/instinctive approach to an investigation was so very different and they might find it hard to communicate!

NEXT STEPS: Do some experiments; masses and springs (extension), masses and springs (vibrations), mass and volume (density), pendulum swings.

NOTE: I should point out that the students are already familiar with the ideas of variables and values in terms of a single experiment, so this is not a rotation they had to go through in the 'framework' steps 1-3. They can easily spot variables and can also usually spot which are linked.

So I want to lead them to a better meta-cognitive understanding of their own procedures and then to a better appreciation of the power of tabulating and graphing results in order to 'see' and understand relationships. Tabulating and graphing should be used, as a matter of course, in all experimental investigations.

e.g.1: one student routinely avoids tabulating results, despite the fact that they save time and effort (his own words!) and allow links between variables to be more easily seen/noticed (looking at what happens to variable 'B' as variable 'A' doubles, etc).

e.g.2: students don't draw graphs without being asked/instructed to do so (this is not at all unusual). I would like it to become automatic as a diagnostic tool. They do automatically look for the variables in any new experiment, so I hope graphing can also become automatic.

e.g.2b: students don't yet know how to use technology (Excel) to tabulate data, draw graphs or find gradients.

e.g.3: students do not recognise that the shape of a graph (particularly the gradient) reveals the character of the relationship between the variables (this is normal at this stage, but I don't want to feed them this information, I want them to discover it for themselves). Also would like them to later on group graphs by shape and identified mathematical relationship.

e.g.4: students do not realise that a graph can be used directly to identify still unknown values (reading from the graph) or that one can extrapolate a graph to unmeasured ranges of values.

e.g.5: students do not do a 'run-through' of the experiment to determine the extremes of the values they will be measuring. This is a useful step (particularly if you're going to draw a graph). They do 'play' with the apparatus to determine all the variables but don't yet recognise this as a valid step in their process. This could also be described as 'playing with the experimental materials' at first.

RESOURCES:

A: http://phet.colorado.edu/en/simulations/category/new

excellent simulations of classical science experiments

SPECIFICALLY:

density lab: http://phet.colorado.edu/sims/density-and-buoyancy/density_en.html

masses and springs: http://phet.colorado.edu/sims/mass-spring-lab/mass-spring-lab_en.html

pendulum lab: http://phet.colorado.edu/sims/pendulum-lab/pendulum-lab_en.html

buoyancy lab: http://phet.colorado.edu/sims/density-and-buoyancy/buoyancy_en.html

B: Thread, balls and timers to allow students to do hands-on pendulum investigation.

More resources to be added later stages.

I have begun this series and will post a report of the first stages this week.

SO what happened?

Well they wrote down their first variation on how to do a science investigation some weeks ago.

In generic terms the original algorithms looked like this;

Introduction - read the question

Hypothesis - what do you think will happen

Materials - get the materials (that you've been told to get)

Write down all the variables - then experiment (this was the full level of detail - no actual instructions from any student)

Method - write a record/description of what you did

Results - record your observations

Conclusion - what did you see in the experiment

STEP 1 - 2: Their idea of how to run an investigation won't work at all. They are stuck but they don't know it. They NEED to become aware of their thinking.

It's pretty clear the students know the layout of an experiment BUT they also clearly expect on some level to be told what to do and how/when to do it, what to measure and so on. There were really no instructions as such contained in their algorithms, except for some isolated instructions in one or two cases. In fact it appears their job, as they see it (from their algorithms only), is to record stuff and do a good layout.

Follow on activity background: - They now go through a number of investigations using the density lab and the mass/spring lab.

DENSITY LAB: This was a lab about collecting data making tables and drawing graphs. The simulation is great because there's loads of variables, length/width/height, volume, mass, displaced volume etc. You can record loads of data AND you can set it as homework (they can do the data gathering at home). This started as a whole class exercise and broke into groups.

MASS/SPRING LAB: This time as an individual exercise. They also had a real spring balance to try out. My instructions to them were 3 challenges A) Can you explain how a spring balance works. B) Can you find the mass of the 3 unknown masses in the simulation (and explain how you did it) C) Can you determine the gravity on planet X (and support your answer).

You could say all of this this is at the stage of 'building a bank' of procedures or 'building steps' with the students such as;

• spotting variables
• looking for which variables affect each other and how
• 'playing' with the materials/apparatus (i.e. discovering extremes/effects)
• gathering data
• making data tables
• taking measurements (accurately!)
• exploring methods for analysing data

There is a certain amount of groping around in the dark at this point (which is productive), because I have not given them any instructions as to how 'I want' them to carry out the investigations. Nor have I given them a list of relationships to look for or even pairs of variables to investigate. They have to make all the decisions themselves.

THIS IS WHERE HAVING A WORKING ALGORITHM WOULD HAVE HELPED THEM!

This approach proved to be frustrating for most students. Some found it only a little frustrating and some found it very frustrating indeed. i.e. they got stuck - "I don't know what to do!"or "what do you want me to do??" this was because the original algorithm (procedure) they had written for themselves were essentially a list of headings or sections of a science report. Hypothesis/materials/results etc. rather than a set of instructions on what to actually do.

This happened at a different point now for each student. It was not possible to do this as a whole class exercise anymore.

HOW CAN I HELP AT THIS POINT? We (student and I) reviewed the steps they were following: I went around to them as they asked for help and asked provocative questions or leading questions. I asked them to explain what they were looking at and what they could see and so on. I asked them had they looked for variables, which variables had they identified, had they discovered any which were connected?  Perhaps they needed to do something else? I would 'play' with the experiment set-up with the student and encourage them to do the same (i.e. show them it's ok not to know exactly where you're going). This gets them past being stuck and usually leads to them seeing variable links by themselves.

Goto PART 2