Hard to Teach – Secondary Science using ICT

Data-logging

Avoiding the barriers and developing higher order thinking skills

Paul Preece - Camborne Science and Community College

Introduction

The world in which we live is changing rapidly as we move towards a more technologically advanced society. As teachers it is our responsibility to prepare pupils for the ever changing demands of the digital world and ultimately for future employment in jobs that currently do not exist. But this is not the only reason we need to include ICT in our lessons. Pupils are already computer literate by the time they arrive in year 7, so science teachers need to embrace the opportunities provided by data-logging to develop higher order thinking skills, thus enhancing and deepening pupils’ learning of science. .

For us to develop the higher order thinking skills of applying knowledge, analysis and synthesis we need to provide opportunities for pupils to draw conclusions based upon the data they have generated. In some cases the only (or best) way to do this is by using data-loggers.

However, in order to interpret the data the pupils need to produce graphs and this is often a huge barrier to pupils getting to the interpretation stage. Graphing is a valuable skill, but also a difficult technique to master for most pupils, especially at KS3. So when the objective of the lesson is to interpret and not specifically the graphing skill then let the data-logger do the work so that the learner can move easily from the collection of data to the interpretation of the data, and potentially onto the application of knowledge to different situations.

This case study focuses on four uses of the most commonly found sensors in schools. pH, light gate and sound plus, for the slightly more ambitious, an example of how a combination of sensors can be useful (oxygen, carbon dioxide, humidity). Although the specific details of the setup of the sensors is omitted a description is provided of how ICT can be used to unlock the potential of the learners by removing some of the barriers to them practising their application, analysis, synthesis and evaluation skills. For the setting up please consult your manuals, as this varies for different suppliers.

Contents

Whichear shape is best?

What happens to the speed of a truck as it rolls down a slope

Combustion

Energy – Sound

Which ear shape is best?

Curricular Context

  • The activity meets the requirements of the KS3 topic Sound and Hearing (8L)
  • Obtaining data from an experiment makes it easier to make the teaching point that the ear shape of different animals can have a dramatic effect on the sensitivity of their hearing. It also relates to the topic of Energy, as energy can be used as the basis for justifying the conclusion obtained.
  • The activity is suitable for all ability ranges.
  • Depending on the depth of activity chosen the activity promotes the skills of planning, application and synthesis..

NB The programme only features the introduction to this activity, in which pupils explore using the sound sensor attached to the hand-held PDA device to investigate loud and quiet sounds and get some idea of what order of magnitude of decibels is involved.

ICT approach

Sometimes in biology, when there is more than one variable, it is difficult to establish which variable makes the biggest difference.. At KS3 the topic of Sound and Hearing explores the concept of how animals detect sound. Using sound sensors it is possible to obtain quantitative results so that conclusions can be drawn.

In this activity pupils explore the effect of the shape of ear flaps on the level of sound detected and apply what they discover to their knowledge of different animals (application). Higher ability students can explain, using ideas from the Energy topic (analysis), why the longer and wider the ear shape the more sensitive the animals hearing will be (synthesis). If you wish there is also the opportunity to explore the control of variables i.e. fixing distance away from sound source, using the same frequency and sound intensity for all measurements etc.

The key elements are that if the length of the cone is altered then the diameter of the open end of the cone must be kept the same (or vice versa). It is best to get different groups to make their own set of longer ear cones (same diameter) or a set of wider ear cones (same length), the results can be collated in a class results table to determine the best shape. A template for producing cones is provided which outlines the way to alter the length or the diameter only.

Method

Equipment needed: sugar paper, rulers, scissors, glue/sticky tape, signal generator, sound sensor, loudspeaker, bosses and clamps.
Pupil activity / Teacher activity
Pupils can predict which shape they think is best.
Pupils can help plan the activity by deciding the variables to fix/control.
Pupils make cones using the templates. It is best if some groups produce and test different length and the others work on the different diameter ear cones.
Pupils can attempt to use the idea of energy to explain why the wider, longer ear cones are better for collecting more sound energy.
For higher ability ask them to explain why wider, longer ears are better for hearing quiet sounds. / Ask pupils why animals have different shaped ears.
Explain that the experiment is to find out what shape of ears is the best for hearing quiet sounds.
The outcomes they need to be guided to are the same distance from source and detector, only change one variable at a time (length or width), same sound level and frequency.
Collate all results and display on the whiteboard so that a conclusion can be arrived at by a class discussion (combination of longer and wider is best).
Remind them that sound is energy travelling through the air.
Turning the situation around and asking which is best for hearing the quietest sound (long, wide) since the others might not even hear it but the long and wide ear cones are more likely to collect enough energy for the sound to be heard.

Benefits of the approach

  • The activity tests pupils’ understanding of sound and energy , whilst providing them with opportunities to control variables, analyse data and apply what they have discovered to deciding which ear shape is best for hearing quiet sounds.
  • The procedure is quick and reliable, producing a robust set of data from which a clear conclusion can be drawn..
  • The activity can be simplified for the lower achievers by providing the set up and they make and collect the results and draw a simple conclusion or even only one variable could be investigated.
  • Practical work that produces data is not common in this area of the curriculum.

Motion – Speed and Acceleration

What happens to the speed of a truck as it rolls down a slope?

Curricular Context

  • The activity fits into the module Speeding Up (9K) in year 9.
  • Using the light gates pupils can easily measure the speed instantly.
  • The activity works on many levels. Pupils can simply justify that the speed increases as it goes down the ramp and then they can change the angle of the ramp to see the effect or for higher ability students they can plot the figures to attempt to explain how the speed changes as it moves down the ramp.

ICT approach

If a trolley moves freely down a slope, it appears to get faster as it nears the bottom. In this experiment the pupils measure the speed of the trolley at different points along the runway. The experiment is a simple one to setup and it gives the pupils easy access to a method for measuring speed.

To measure the speed of an object is a difficult. Light gates with interrupt cards are easy to set up and graph created provides immediate feedback so that the pupils can see the speed instantly at that part of the slope. This can lead onto investigating what might happen if the slope was extended, or if the angle of the slope was changed

Method
Equipment needed: 1 to 1.5m slope, a dynamic trolley, a straight piece of card, meter rule, light gate.
Pupil activity / Teacher activity
Pupils setup the experiment for themselves. They then collect data at various points on the slope by running the trolley several times and moving the light gates to a different point each time. / Ask pupils to explain what happens to the speed of an object as it rolls down the slope.
Ask why is rolls faster (bring out the ideas of force of gravity and low friction to make the trolley roll easily).
For higher ability students you can get them to produce an Excel plot of the speed against length.

Benefits of the approach

  • To measure the speed without a light gate is very difficult. It can be done using ticker tapes, but the technique is difficult to master and can be a distraction. Using light gates gives immediate results with no difficult analysis required, thus making the measurement speed strauightforward..
  • Easy access to speed measurements allows the pupils to explore how the speed changes when forces are applied.

Plot from the spreadsheet provided

Particles – KS3/4 Combustion

Curricular Context

This is a more demanding experiment because it uses three sensors. Prior experience of setting up and using the sensors is advisable. This activity addresses the Combustion part of the KS4 syllabus.

  • It is difficult to teach the combustion equation and the need for oxygen in combustion. This activity shows how the amount of oxygen in the air determines how well a fuel combusts. The production of carbon dioxide is often forgotten by the pupils so this can be addressed by this activity.
  • It works on many levels. It can kept as a simple demonstration for lower achieving students or for establishing and justifying the equation for combustion with the more able.

ICT approach

Combustion is a process which is taught throughout KS3 and KS4. When pupils are asked “if a candle was placed in a bell jar how much oxygen you would need for combustion to occur?” they would probably say “when the oxygen runs out!”

Also if you asked what is also produced along side heat and carbon dioxide they would (in most cases) not mention water. By using oxygen, carbon dioxide and humidity sensors it is possible to demonstrate that with approximately 16% oxygen in the air the candle will go out and that water and carbon dioxide are produced.

This visual demonstration shows in real time how the oxygen is ‘used up’ and the ‘carbon dioxide is produced’ as one line drops the other increases. This provides the opportunity to establish that the oxygen is being used to react with the fuel and released as carbon dioxide. But if a humidity sensor is also available the humidity will increase during the time that the candle is burning indicating that water is also produced during combustion. As the quantity of oxygen approaches around 16% the candle flame reduces in size and eventually goes out. At this point combustion ceases and the oxygen level stops going down also the humidity also stops increasing therefore linking the use of oxygen and production of water when combustion occurs.

Method

Equipment need:Large bell jar, rubber bung with notches to allow the wires for the sensors to be fed through but keeping it almost air tight, humidity sensor, oxygen sensor, carbon dioxide sensor and a candle.
Pupil activity / Teacher activity
Pupils share their thoughts as to what will happen when the candle is lit. This provides the opportunity to test the pupils’ knowledge of the process of combustion.
Get pupils to write the combustion equation and justify from their results how they know what the products are and what the reactants are. Pupils can write on the worksheet to aid this process. There are two pages, one with the word equation and the other with the formula equation. / Set up the experiment with the data logger ready to plot in graph. mode the amount of oxygen , carbon dioxide and humidity. Discuss with the pupils the purpose of the apparatus and set the graph plotting without the candle lit. Ask the pupils to describe what will happen to the levels when the candle is lit.
Set the candle burning and give the pupils time to see that the oxygen level is dropping and the carbon dioxide level is increasing. Then ask the question when will the candle go out?
Once the candle has gone out indicate that the oxygen level does not have to be 0% for the combustion to occur.
Introduce the combustion equation and show that the fuel and oxygen are used up (reactants) since they go down and that the carbon dioxide levels and humidity goes up which means that they are produced products.
For higher students you could reverse the argument and ask them to suggest what would happen if a plant was placed in the bell jar filled with a high percentage of carbon dioxide and humidity (compared to normal levels).

Benefits of the approach

  • Since the pupils cannot see the particles involved in combustion they find it difficult to grasp what is going on. Also combustion is complicated equation to teach and pupils often find it difficult to remember the reactants and the products. This is a visual way to demonstrate that combustion really does use oxygen and produce water and carbon dioxide.
  • The sensors show in real time that when combustion occurs that reactants are used and products are produced and data is produced to represent this.

It provides an opportunity for the teacher to embed the process of combustion by relating the equation to real results. .Pupils then have a greater appreciation of what the equations represent.

  • The pupils can see for themselves what happens rather than relying upon teacher knowledge.

Note to teachers

This document was not created by Teachers TV but the author has allowed us to publish it here to be used for educational purposes