Characterising and studying the processes worked out by the teachers for labwork

Characterising and studying the Characterising and studying the processes worked out by the processes worked out by the

teachers for labworkteachers for labwork

Hélène Richoux, UMR ICARHélène Richoux, UMR ICAR

Translation : Vincent ParbelleTranslation : Vincent Parbelle

IMPRESSE – Berlin – April 2007

IMPRESSE - Berlin 2007

• A tool to describe the instructions given to students during A tool to describe the instructions given to students during laboratory workslaboratory works

context of its construction and presentation of the toolcontext of its construction and presentation of the tool

• Using this tool to characterize students’ tasks, to analyse Using this tool to characterize students’ tasks, to analyse processes, … processes, … Two examples with a similar learning objectiveTwo examples with a similar learning objective

Two examples Two examples labelled “inquiry process”

• From a guided to an inquiry process…questions about physics and chemistry teacher training

Characterizing and studying the processes Characterizing and studying the processes worked out by the teachers for labworkworked out by the teachers for labwork


1h1/2 each week for all students (15 years old) 1h1/2 each week for all students (15 years old)

2h (or more) each week for students who learn 2h (or more) each week for students who learn sciencessciences

Practicals in physics and chemistry in French Practicals in physics and chemistry in French lower and upper secondary schoollower and upper secondary school

- Small groups of 2 or 3 students in a specially equipped laboratory

- scientific equipment for each group :tailor-made for schoolsstandard

- generally, a worksheet instructs

the students what to do


Examples of worksheetsExamples of worksheets

SHED YOUR LIGHTS…

Achille Talon, his father and his neighbour go camping. They have at their disposal 3 tents but only one battery.

•You have to set up an electric circuit which will allow to light up each tent, independently from each other.•First, you will work individually, then as a group. During group work, you have to suggest a solution and argue your choice.

DRIVEN OSCILLATIONS OF A RLC CIRCUIT

I. Recognizing the driven oscillations Set up the circuit shown

Complete the diagram with the measuring devices. Plot the graphs u(t) and i(t)…

II. The phenomenon of resonance Add an ammeter to the circuit Give different values to the frequency and plot the values of f and I. Plot the graph I(f). Determine the value of the frequency … Observe and plot the graphs u(t) and i(t) …


A method to describe and analyse the A method to describe and analyse the tasks given for learningtasks given for learning

Many discussions and criticisms about the tasks given to Many discussions and criticisms about the tasks given to the students for learning, about the processes elaborated the students for learning, about the processes elaborated by teachers, about the uses of data …by teachers, about the uses of data …

The use of computers in school laboratories to modify The use of computers in school laboratories to modify teaching processesteaching processes

A research to study the evolution of teachers ‘ practicesA research to study the evolution of teachers ‘ practices

•The context: a research on labworkThe context: a research on labwork in Francein France (1998, Beaufils & al.)(1998, Beaufils & al.)

• A tool to analyse the tasks: a complex grid to A tool to analyse the tasks: a complex grid to characterize the instructions written on worksheetscharacterize the instructions written on worksheets

• A new grid adapted for teacher trainingA new grid adapted for teacher training


Description of the instructions to studentsDescription of the instructions to studentsI. Using information from a text, a table, etc.. O. Observing, with or without manipulation C. Choosing, guessing, suggesting

A. Assessing the quality/validity S. Sketching/drawing K. Calculating, analysing (numerical results) R. Realising, carrying out an experiment with objects or instruments G. Giving an answer, a result T. Telling/writing down a (required) piece of knowledge


Aim of this practicalWe will study the evolution of the pressure of the amount of air in a syringe according to its volume.

Data processing :- Enter in the spreadsheet the values of V and P for each reading.- Compute 1/V,- Plot the graph P = f(1/V)- Find a straight line of best fit for these values- Deduce from the modelling result that the product PV remains constant throughout this experiment.

Boyle’s Law -1Boyle’s Law -1

Experimental device :- Lock an amount of air in the syringe, at room temperature, ….- Connect the other end of the tube to the pressure sensor.- Connect the pressure sensor to the computer …- Press the piston (very slowly) and collect about ten values of volume V and air pressure P.


A first analysis of the instructionsA first analysis of the instructions

Teaching objective : Boyle’s Law II

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Behaviour of gases at low pressuresBehaviour of gases at low pressures ((Boyle’s Law -2Boyle’s Law -2))

• To start with, discuss the following questions with your partner :What are the four macroscopic quantities relevant to describe a gas ? When Boyle’s law can be used, what are the fixed macroscopic quantities and those that can change ? • With the following set of apparatus, … suggest an experimental protocol to answer the initial question.

A discussion between all groups will lead to agree on a relevant protocol. • Carry out the protocol chosen by the class.• Write down your experimental results and the answer to the initial question with your arguments to support it.

Terms of Boyle’s Law At low pressure, all gases have the same behaviour. We note that, at a given temperature, for a given amount of gas, pressure and volume are linked by the relation PV = constant.

“Is Boyle’s law satisfactory to predict the behaviour of the air inside the classroom at the usual pressures?”


Behaviour of gases at low pressuresBehaviour of gases at low pressures

Second part :

During the work you have just realized, you have taken care to keep both values of temperature and amount of gas constant. Now the new question is

“what happens to the «« Boyle’s constant »» if temperature or the amount of gas is modified.” Using the gas kinetic model, predict how the product pV will be modified if :- temperature is modified (while keeping n constant)- the amount of gas is modified (while keeping T constant)

With the equipment avalaible, imagine an experimental process that would allow you to check your predictions in both cases and describe it on your sheet.

If you have time, show your suggestion to the teacher and run your experiment. If you don’t have time the teacher will choose two suggestions among those given by the class and will carry them out during the next session.


A first analysis of the instructionsA first analysis of the instructions

The main teaching objective : Boyle’s law II

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A ‘new’ way for teachingA ‘new’ way for teaching

• « La main à la pâte »« La main à la pâte »

• Teaching units elaborated in a socio-constructivist model in a Teaching units elaborated in a socio-constructivist model in a context of didactic researches, tested and publishedcontext of didactic researches, tested and published

•Instructions into the curriculum of French upper secondary Instructions into the curriculum of French upper secondary school (1999, 2000) and examplesschool (1999, 2000) and examples “… Experimental activity in education helps pupils to develop a scientific mind

only if it is accompanied by actual questioning and modelling.”

•Instructions into the curriculum of French lower secondary Instructions into the curriculum of French lower secondary school (2006) and examplesschool (2006) and examples “In continuation of the method employed at primary school, lower secondary school curricula favour the inquiry process [...] an approach that promotes

the pupil's own build up of his/her knowledge.”


One of the causes of the rise of ocean levels isOne of the causes of the rise of ocean levels isthe melting of ice.the melting of ice.Ices are constituted by:Ices are constituted by: Sea-ice (e.g. icebergs): ice on the oceans Sea-ice (e.g. icebergs): ice on the oceans and seas.and seas. Icecaps (e.g. mountain glaciers): ice on the Icecaps (e.g. mountain glaciers): ice on the continentscontinents

A labwork labelled “inquiry process”A labwork labelled “inquiry process”

Glaciers meltingGlaciers melting

•Does the melting of sea-ice have an effect on the rise in the sea Does the melting of sea-ice have an effect on the rise in the sea level?level?•Does the melting of icecaps have an effect on the rise in the sea Does the melting of icecaps have an effect on the rise in the sea level?level?•What is an estimate of the rise of the sea level in 2100?What is an estimate of the rise of the sea level in 2100?


On a winter night, Policeman Bignose is on duty in a shoppingOn a winter night, Policeman Bignose is on duty in a shoppingstreet with a speed camera. The red neon lights of a store arestreet with a speed camera. The red neon lights of a store arelighting the street.lighting the street. A fast car appears suddenly. Policeman Bignose reaches for hisA fast car appears suddenly. Policeman Bignose reaches for hiswalkie-talkie and sayswalkie-talkie and says::““Chief, chief, someone speeding! A black car going at 138 Chief, chief, someone speeding! A black car going at 138

km/h!”km/h!”

A labwork labelled “inquiry process”A labwork labelled “inquiry process”

The colour thief !The colour thief !

You are a scientific expert and you are the friend of the accused. You are a scientific expert and you are the friend of the accused. HowHow can you help him prove that he is innocent and find who the can you help him prove that he is innocent and find who the reckless driver is?reckless driver is?

His colleagues, one kilometre further down the street are ready to stop the reckless driver! His colleagues, one kilometre further down the street are ready to stop the reckless driver! In the white light of their headlamps, they see a red, then a green and a white car drive by. At In the white light of their headlamps, they see a red, then a green and a white car drive by. At last a black car appears. They stop it. But the driver contests the offence:last a black car appears. They stop it. But the driver contests the offence:

« My old car cannot go over 110 km/h !! »« My old car cannot go over 110 km/h !! »..


From a guided to an inquiry processFrom a guided to an inquiry processHow can a teacher recognize an inquiry process?

A model based on tasks (Morge & al.)

•The sequence includes a chain of tasks and the teacher delegates to the students the responsibility to carry them out themselves.

•Students answer the tasks by elaborating productions

•Students are able to take part in controlling the whole process and actually do it.

•The control of the findings is carried out by testing validity, relevance.

•Students acquire knowledge through carrying out tasks.

•Students are in charge of conceptual tasks and not only empirical tasks.

Morge L. & Boilevin J-M (to be published) Des séquences d’investigation en physique-chimie au collège et au lycée:Recueil et analyse d’exemples issus de la recherche en didactique des sciences physiques et chimiques


From a guided to an inquiry processFrom a guided to an inquiry processA necessary training to develop teachers’ expertise…

•To analyse teachers’ productions in terms of learning and teaching

•To know students’ prior knowledge,

•To know the relevance, the importance of inquiryfor student learning, for student implication/involving in the study,in relation to science processes,

•To know how to lead students within an interactive practice,

•To construct (to adapt) their own lessons

•To analyse, to assess their own teaching units in terms of students’ learning, students’ behaviour, organization, difficulties …. Adopting any innovation is a long and complex process

See for example: Understanding innovation in science teachinghttp://www.pjb.co.uk/npl/bp33.htm

Characterising and studying the processes worked out by the teachers for labwork

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