IT for handling data and models in science

Background (1995)

This document suggests a number of practical activities for handling data and ‘modelling’ with a computer. It also provides some case studies of how science departments have equipped themselves.

The activities draw upon current practice and have been chosen because they help to introduce IT to pupils and staff. More than this, many of the activities are relatively easy to implement and yet they still enhance, or add-value, to typical science activities.

The curriculum makes a clear reference to the ‘appropriate’ use of IT in science. That can be seen as an opportunity to explore many avenues: new software, new technology, the Internet and so on. It also implies that teachers and pupils should evaluate the worth of the technologies they employ. So while the ideas here draw upon current good practice, and are recommended, everything is up for judgement in your situation, and with your pupils.

The ideas have been organised under the following headings:

Using CD-Rom

Using spreadsheet programs

Using database programs

A final section looks at hardware.


Using CD-Rom: computer models and facts

CD-Rom uses a computer readable 'compact disc' to store programs and data. It is already replacing floppy disc based software, although unlike floppy discs the computer can usually only read, but not write information on the discs.

The CD-Rom can store hundreds of times more information than can a floppy disc and this allows you to enjoy full colour photographs, animation, voice commentary and film clips. This increases the processing demands on your computer, so you will need the best computer you can afford to get the most enjoyment and not be frustrated by slow running machinery.

Schools have had a variety of success in providing CD-Rom access to a large number of computers (networking) so CD-Rom is usually found on stand-alone machines. One tip is that a 17 inch screen monitor will be helpful when you want to discuss what on the screen. However, things change fast.

It is important to realise that the vast majority of CD-Rom titles with science content were produced for the ‘home’ market and not the classroom. The ‘home’ titles can be truly stunning and hard to dismiss. But the question of what is ‘good’ is really one of judging whether the title can stimulate the learner, or be used to teach, or to learn from. Therefore in addition to judging a piece of software as good or bad, you might find it helpful to classify it as being most suitable for the home, the library or the classroom.

Encyclopaedias

A CD-Rom encyclopaedia can help when you are faced with a question which either you do not know the answer to or you are inclined to tell pupils to find out for themselves! The benchmark CD-Rom encyclopaedia of the moment is Microsoft’s Encarta ’95 (PC or Mac, Microsoft).

If you needed to find out about salt, you could type in the word ‘salt’ and see what appears. You will find Salt the mineral and Salt, as in Strategic Arms Limitation Talks. If you click on ‘salt’ the program tells you what salts are, how they are made and about sodium chloride. It tells how it is extracted and where it is found, such as the Great Salt Lake in the USA. It offers interesting snippets too: about Roman soldiers being paid their salary as salt, and that salt blocks are used by cattle on a farm.

If you want to explore further, you will find much here. You can read about its industrial preparation, or neutralisation, or halite or the alkali metals. Although the reading level is sadly, at or just below advanced level, younger pupils are using this resource. It may be kept in the library, and pupils can take out pictures and use them in projects or they can highlight the key points of the text in a word processor program.

One ‘warning’ is that ‘Encarta’ is very distracting: teachers and pupils will soon find themselves exploring Salvador Dali, or Salvation Army or whatever catches the eye.

Models

As a rare bonus, Encarta’s Nutrition section has a surprisingly useful diet analysis program. You simply click on the foods you ate today, say how much you ate (as in two slices of bread) and enter your age and sex. One more click and you see a nutrient by nutrient breakdown of your diet, shown as a bar graph.

The dietary program is a good example of what is meant by modelling with a computer. The computer holds all the data on different foods, even the vitamin C content of a Kiwi fruit and can do the necessary calculations for you. So if you find that your fat intake is too high, you can play with the model, try boiled eggs instead of fried, and see how you are achieving your goal.

Another modelling title is Multimedia Motion (Cambridge Science Media, PC). This is the CD-Rom of a Laservision disc, some will have seen many years ago, but it stands the test of time. It allows you to analyse over fifty filmed motion sequences, measuring time, distance, velocity and acceleration in a unique way.

Imagine a film clip of a tennis ball hitting a racket. Imagine too, that you can control the film, frame by frame and see the action step by step. Using this CD-Rom you can click on the ball in one frame, advance the action, click again and plot a dot and keep doing this until you have a series of dots on the screen. In just one more click the dots are plotted on a graph, with time along the bottom axis and distance up the side. You can change the axis and plot velocity or acceleration against time. You can take readings from the graph and calculate say, the average acceleration of the ball or compare the speed of the ball before and after it hits the racket.

There are sequences showing free-fall, car crashes, train crashes, spinning objects and so on. There is also a commentary and help with data such as the mass of the tennis ball and formulae. The title has been very well received, and the only criticism I have heard is that the motion sequences chosen could have been more exciting. Physicists will be able to pick this up quickly and run.

Handling information

Likewise, biologists this time will be able to work wonders with Plant Science (Attica, PC). This isn’t a model to explore, but it is a huge bank of information for GCSE and A level. There are pictures of plants and case studies of successful experiments. There is an identification ‘key’ where you enter details about a plant you may have and it helps you to find out more about it. In a unique section called ‘Plan’ the pupils are prompted, step by step, through planning an experiment. It helps them to control variables, or choose a species to investigate, and they can explore the information as they develop their experiment plan. Plant Science isn’t the singing and dancing affair you associate with CD-Rom titles - it is a serious tool that biologists will find valuable in their classrooms.

A few of the titles intended for the ‘home’ also have a place in school. The Eyewitness Encyclopaedia of Nature (Dorling Kindersley Mac or PC) is above average. It allows you to visit habitats in various parts of the world, to see the animals there and see the food webs within a habitat. You can use it as a discussion point in the classroom, or place it in the library as stimulus material. You could do the same with The Ultimate Human Body (Dorling Kindersley Mac or PC) where even the youngest pupils will ‘enjoy’ removing eyes, nose, heart and lungs bit by bit from a very graphic human body. They can click also on things and read about them in detail, and you will appreciate several animated sequences that describe how peristalsis works or how the circulation works. As a disc for the library, this generates a crowd, not always for the right reasons of course, but it is all science.

And returning to physics, but still in the library, The Way Things Work (Dorling Kindersley, Mac or PC) is an especially interesting and fun look at how everything from the laser printer to the salad spinner works. There are profiles of the inventors, a time-line of inventions and detail about electrons (in how a battery works) or electromagnets (in an electric motor). A favourite, under the scientific principles of light, might be the chicken posing for the camera under three spotlights, one red, one blue and one green. You can switch on the lights in pairs and see the colours mix.

These then are a sample of current titles. They involve handling data (including word and pictures) and useful models for teaching. There is more, but this shortlist is shortened by the need to get a balance of things that help make science enjoyable and things we could use to teach with.

Using spreadsheet programs: handling data


If you need to handle data in science a spreadsheet program could be the first tool to pick. You can use one as a ready-made table to record the results of an experiment and then turn the table into a graph.

You can also sort the table and quickly answer questions such as "which is the biggest?" or "which is the best". Many teachers have discovered how these programs can be used as a mark book for storing assessments. That’s not a curriculum use of course, but it is the way many teachers have developed their spreadsheet skills for later use with their classes.

A special feature of a spreadsheet program is that it can do calculations. In the mark book example you can take a list of test marks and work out the average value. In some work on Ohms Law you could take readings of voltage and current and then use the spreadsheet to work out resistance. And in some work on motion, you can use the program to work out speeds, using time and distance values.

Things become really interesting when you use spreadsheets to create mathematical models. For example, you might do a survey of the amount of water used at home. You could create a table with a column for how much water is used by a bath, a hand wash, a clothes wash, a toilet flush and so on. Beside it you could have another column where how many baths, hand washes, clothes washes and so are entered. Finally, you can calculate and total the results and show the total amount of water used in a day, a week or a year.

You can them ask questions such as ‘if we half-filled the bath, how would this affect the amount of water we used’ and you would change figures in the table to see the result.

The water example is one of several models you might build. You could use a spreadsheet to look at the use of electricity, or model chemical equilibrium, population dynamics or the discharge of a capacitor.

Spreadsheet example: Testing cotton reel rollers

In this activity the pupils test the idea that the more times they turn an elastic band on a cotton reel roller, the farther the roller will travel. They might start their experiment, by twisting the elastic band twenty times and then see how far the roller travels. They might then test 30, 40 and more turns of the band, they might also see if they can repeat their results.

They can enter their results into a spreadsheet just as they might enter it into table. The spreadsheet has been set up for them so that it will calculate the average of each run. They can then produce a graph showing the relationship between turns of the band and the distance travelled. They can discuss what kind of graph - bar chart, line chart or scattergraph is best to present their results. They might even extrapolate their graph and predict how far a roller would go if they twisted the band an even-more number of times. They might then test this prediction in practice.

When you look at published textbooks and science schemes, drawing a graph is often the end product of an experiment or a homework. It’s even used, let’s be frank, to keep pupils busy. Yet surprisingly little time is spent on looking at the graph and this activity, by saving the time spent on graph drawing, allows you to take the work further.

Spreadsheet example: Launch pad

The pupils might try to answer the question: What is the best angle to throw a ball into the air if you want it to go the farthest. They might approach this by making a catapult using elastic and cardboard. They might test how far they can launch a paper ball by setting the catapult at different angles.

They can enter their results into a spreadsheet table, average the results of repeated attempts, and plot the results on a scattergraph. This graph might have the launch angle along the bottom and the distance travelled up the side and the result can be shown as a series of scatter points. The points should be in the shape of a hyperbola with the peak or ‘best’ angle coming out as 45 degrees.

As in the previous exercise, the pupils can reach the stage of interpreting their results sooner by using a spreadsheet. And should their results not match their expectations, they may also be able to repeat some results, plot them and discuss them in the same lesson.

Much time is spent tabulating and graphing results in science. That these two activities have much in common is deliberate: teachers and pupils can master the fairly easy skill of plotting a graph with a computer and then apply it to many activities. They can graph the growth of a plant, compare pulse rates across the class; make acid-base titration graphs, or draw a pie chart of the gases in the air. The job of graphing and analysing data on the computer can become a fairly easy ritual.

Further up the school you can extend pupils' skills with slightly more challenging work. In the last two examples, the calculation feature of a spreadsheet is used.

Spreadsheet example: How the length of a wire affects its resistance

You might set about measuring the current passing through lengths of constantin wire. The pupils can enter the results into a spreadsheet and calculate the resistance of the wire. Doing a calculation on a spreadsheet is something which pupils in years 9 and above should certainly be able to do. They can then plot a scattergraph (an x-y graph) of wire length against its resistance.

Spreadsheet example: Water in soil - How much of soil is water?

In this experiment the pupils weigh samples of soil in a dish before and after heating them. Instead of putting their results onto paper they enter them onto a spreadsheet. The program helps them with the calculations: it subtracts the mass of the dish from each weighing, and it calculates the percentage of water. You can also collate the results of the whole class and plot these on a graph. You might do this to see the level of error or compare soil samples from different locations.

I have frequently found pupils fazed by the simplest calculations - and it’s rarely because they can’t do them. The reason may be that the calculation has been a distraction and if so the computer can help by allowing the pupils to focus on their results. Once we’ve looked at the results, and discussed the underlying pattern, we have gone back to look at how we got there.


Databases

A database program is another IT tool that allows you to handle data. These programs are especially good at handling the results of surveys. For example you might survey people’s smoking habits or their health awareness. You might survey cars in a car park to find how their age affects corrosion and which parts corrode first. Whenever there is a lot of data that needs organising and analysing, a database program can be useful.

Organising and structuring data for a database program is very much a scientific process. Database programs almost insist that pupils think carefully about the data they collect and how they enter it into the computer. They may be faced with questions such as: how will we record the amount of rust? How will we record the car’s age? They will need to distinguish between relevant information, such as the brand of car and less relevant information, such as whether it has fuel injection.

At the lower end of the school, you might provide the pupils with a database ready for them to add their data. Further up the school, perhaps by the end of Key stage 3 they may be able to do this for themselves.

Database example: How we differ

The most successful, and most used survey is one about ‘ourselves’. It has been used in teaching about human variation - but it’s also a good introduction to data analysis.

The starting point for the activity could be a discussion where various hypotheses about ‘ourselves’ are proposed for testing: for example, do younger people have faster reaction times, do people with blonde hair have blue eyes, or do taller people have more lung capacity. The pupils can set about deciding what data they need to collect and ensuring that they are consistent about how they collect it. They will eventually enter the data and check it for errors.

They can then set about testing the suggestions they made using the program. They might search the data for those with blonde hair and draw a pie graph of their eye colours. They might plot a scattergraph of height against lung capacity. They might plot age against reaction time. They may even digress and find other patterns in their data.

This activity may take a couple of lessons or more, it may require some upheaval in the timetable, for example, you might borrow the school’s computer suite for the duration or enlist the support of a member of the IT staff. However, with planning pupils can achieve a valuable level of data handling skill which could help them at many points in the future.

Database example: Planetary Patterns

There are many patterns in the data on the planets. For example, there is a pattern between the planets’ distance from the sun and the time for a single orbit. There is a pattern between the gravity of the planet and the number of moons that it has.

Using a data handling program, pupils can analyse planetary data very easily. You can start by giving the pupils a ready-made database on the planets. You might go over technical points such as what we mean by ‘surface temperature’. You might ask for a handful of possible patterns and see if pupils can explain them.

It takes just a minute or so to plot a scattergraph of the distance against the orbit time. Trying another idea is but a minute away so this is an excellent place to experiment with data. This activity ought to fit very nicely within a lesson.

Some data handling packages do this activity much more easily than others so it is worth discussing it with the IT staff beforehand. They should be able to recommend a suitable program to use.


Equipment and resourcing scenarios

Computers and resources

Whether you have the resources to try activities such as these is a big issue. There is a kind of Catch 22 to getting computer resources: if you do not have the computers you cannot use them, and if you do not use computers, it is harder to persuade people to give you funds to buy them!

Through various initiatives and those occasional bits of money, some science departments have acquired a ‘critical mass’ of computers and moved on noticeably. Bear in mind it is also possible to have too much equipment - or more that you can realistically manage in a lesson! The following four case studies may point to a suitable type and level of resources.

Dept A

The science department has several desktop computers around the department. These are quite old now but they are on trolleys and as the entire dept is on a single level, they can be wheeled into any science lesson. These computers are used exclusively for data logging and the dept has invested in a basic sensor kit for each one. The department also has two fairly modern machines, one of which is connected to a laser printer. This is rarely moved from the science office and is used by about half of the dept for keeping records and word processing. The other modern computer is a multimedia PC which someone managed to connect to a large television. This is used by two members of staff for work with CD-Roms and spreadsheets. Pupils frequently browse through the CD-Roms at lunch time.

Dept B

Also has two modern computers in the dept. They are well placed being just along the corridor from the school’s main IT suite. The key to this room is kept close-by in the prep room. They have invested some funds in a set of eight data logging kits which they take to the IT room to do fairly 'clean' experiments. In one or two lessons, a member of staff takes a class into the IT room. They use the data logging software to examine a graph from a pendulum experiment in detail.

This year they have timetabled a science project in the IT room. The project took shape when a teacher decided to give the database idea a try after going on a course. The pupils use the IT facilities to plan and create a database of pupil measurements. The IT co-ordinator has helped by setting up a system whereby the results of different classes can be collated into a single datafile. This the pupils can analyse. A member of the IT staff is timetabled to provide teachers with support when it is their turn to try the activity.

The dept is not over happy about their trip to the IT room as it is slightly disruptive, but in time the department hope to acquire their own set of computers.

Dept C

The dept has a set of six laptop computers each with a basic set of sensors. They obtained these through a bid they made jointly with the geography dept. They also have six data logging interfaces with a dozen temperature probes. In their workschemes, they have highlighted three lessons per class per year when they will use them. A member of the dept has the responsibility for implementing the use of IT in science.

Perhaps surprisingly, the laptops are used mostly for graph work with spreadsheets. Two members of staff have been getting their pupils to write experiment reports on a word processor and ‘pasting’ their graphs into that.

The laptops are kept on a trolley, and the batteries are charged by the technical staff. The equipment is stored in sets with each in a separate tray. The items in the tray, such as sensors and cables, are labelled with coloured spots to aid fault finding.

The computers are booked with an equipment requisition slip and a wall timetable shows advance bookings. They have a portable colour ink-jet printer for printing out, and printing causes a bottleneck at the end of a lesson.

Dept D

This science dept has one CD-Rom desktop computer, 3 laptop computers and 4 palmtops. (A palmtop is a very small handheld computer.) They also have a sensor kit with two temperature probes, for each of these computers. This allows them to do experiments with the whole class - although after the palmtops have collected the data, it has to be transferred to the laptops for printing. They are nevertheless pleased that the set-up allows more pupils to use a computer.

They find the palmtops especially valuable for recording results from manual experiments. Pupils very quickly learned to use them to draw graphs with the built-in spreadsheet. They also took the palmtops on a field trip and again pupils used them to record results. They aim to get a class set of palmtops when funds become available.

Finally

It is possible to start handling data with a single computer at the side of the laboratory. Many teachers have begun in this way. However, when departments have had easy access to a greater number of machines the use of computers has increased markedly. Laptop and palmtop computers are particularly useful here, not least because they can be brought to the science instead of the science going to the computer.

For a number of reasons, some connected with the heavy requirements of the first National curriculum, the expectation of what science teachers should be doing with IT in their classrooms is significantly ahead of what is immediately possible.

We should nevertheless strive hard to explore what IT has to offer because it can seriously benefit our teaching. The activities that we start with do not need a great deal of skill or equipment: if we choose activities which are within our means, we have a chance of success. Success may breed success.

 


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