ISA Guide

For Core Science By Mr J Kenny

Section 1 There are usually 5 questions. Questions 1, 3 and 5 are generally very similar and examples are given below.

Question 1 Think about the research that you did to find out how to test this hypothesis.

Name two sources that you used for your research.

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Which of these sources was the more useful and why?

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(3 marks)

People tend to drop marks here by saying why the better source was good without commenting on the second source.

Question 3 In this question you will be assessed on using good English, organising information clearly and using

scientific words where appropriate.

Describe how you plan to do your investigation to test the hypothesis given.

You should include:

the equipment that you plan to use

how you will use the equipment

the measurements that you are going to make

how you will make it a fair test

a risk assessment.

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(9 marks)

People tend to drop marks here by

not explaining how the equipment will be used, i.e. not giving step by step instructions on how to do the practical. not stating control variables and how they will be controlled. not organising their answer logically or, poor spelling, punctuation and grammar.

Forgetting to do the risk assessment

Question 5 – completed before the exam

5 Make sure that you hand in your Candidate Research Notes and your blank table for the results with this paper.

You will be awarded up to two marks for your table.

(2 marks)

Marks dropped on this question are generally due to a lack of units on column headings.

Question 2and 4 vary from paper to paper and examples include.

2 In this investigation, you will need to change the area of the solar cell exposed to the light.

Describe briefly how you would do a preliminary investigation to find a suitable interval to use for this variable.

You should also explain how the results of this preliminary investigation will help you to decide on the best interval to use.

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(3 marks)

2 In this investigation, you will need to control some of the variables.

Write down one variable that will need to be controlled.

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Describe briefly how you would do a preliminary investigation to find a suitable value to use for this variable.

You should also explain how the results of this preliminary investigation will help you to decide on the best value for this

variable.

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(3 marks)

4 Do you think that the level of light in the room in which you are going to do the investigation will be important?

Explain the reason for your answer.

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(3 marks)

4 When you have completed your investigation, you will be asked to share your results with others.

Explain the advantages of sharing your results with others.

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(3 marks)

4 In your research you will have found other methods you could have used.

Briefly outline one other method you could have used.

Explain why you chose not to do this method.

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(3 marks)

Section 2 As with section 1 there are some questions which come up in most papers and some questions which vary with each

paper. Questions 1a, 1d/e, 2a, 2b, 3, 4 are generally the same, the others vary from paper to paper.

Question 1 (a) What were the variables in the investigation you did?

The independent variable was .......................................................................................... .

The dependent variable was ............................................................................................ .

One control variable was .................................................................................................. .

(3 marks)

Marks dropped are usually due to not being precise enough with wordings e.g. by saying ‘the emulsifier’ instead of ‘the

volume of emulsifier’, or by getting independent and dependent variables confused.

Question 1 (d) The hypothesis that you were given before you started the investigation was:

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Do your results support this hypothesis?

Explain your answer.

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(3 marks)

Marks dropped are usually because of a lack of detail to get to the 3rd mark. It is often useful to quote examples from

results.

A simple description might be when A increases so does B.

A detailed description might be that B is directly proportional to A, as can be seen from the straight line on the graph

which passes through the origin or the fact that results for B double when A doubles (quoting numbers from results).

Question 2 You have been given a Secondary Data Sheet that provides results from similar investigations.

2 (a) Draw a sketch graph of the results in Case Study 1.

The graph should show how the mean time for the mixture to separate varies with the volume of egg yolk used.

(2 marks)

When marks are dropped it is usually for the line, the axes headings can be copied from the table of results and do not

require units. The line should be either a smooth curve or a straight line drawn with a ruler. If two lines can be seen then

the mark will be lost.

Question 2 (b) Explain whether or not the results on the Secondary Data Sheet support the hypothesis you were

given.

To gain full marks your explanation should include appropriate examples from the results in Case studies 1, 2 and 3.

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(3 marks)

Very few candidates get 3 marks here, for one of two reasons.

Either they forget to give examples (e.g. write numbers from the results table) or because they run out of space and have

not given sufficiently detailed explanations of both case studies 2 and 3. There is usually one of case studies 2 or 3 where

the results are irrelevant because the variables are not those of the hypothesis investigated. The other usually supports

the hypothesis but to give a detailed explanation something else is required. e.g. It could be that the results support the

hypothesis in general but the pattern seems to level off for higher values of the independent variable suggesting that

there is a maximum value of the dependent variable.

Question 3 How could the results from your investigation be useful in the context you have researched?

You may use information from your Candidate Research Notes to help you to answer this question.

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(3 marks)

Few candidates score 3 marks on this question. You must find some way in which your results can help in the context give.

As this question come up every time and the context is given beforehand, this is definitely an example of a question where

planning what you will write before the exam is likely to gain you at least 1-2 marks.

Question 4 – completed before the exam

4 Make sure that you hand in your Candidate Research Notes, results tables, and chart or graph with this paper.

You will be awarded up to four marks for your chart or graph.

(4 marks)

If marks are dropped it is generally because of one of a few things.

Plotting points in the wrong place (choose yourself an easy to use scale)

Joining the dots rather than drawing a line of best fit (never join the dots unless you know why you are doing it)

Forgetting to label (with units) the axes

Having an incorrect scale on axes, e.g. 1 square from 0 to 5 and two squares from 5 to 10.

Drawing a line of best fit which has lots more points on one side (above/below) than the other.

The other questions in section 2 vary from paper to paper. Some examples are given below.

1 (b) What difficulties did you have in getting accurate results?

Explain how these difficulties could be overcome.

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(3 marks)

1 (b) Resolution refers to the smallest scale division of a measuring instrument.

What was the resolution of your measurement of the volume of emulsifier?

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Do you think that this resolution was appropriate for this measurement ?

Explain your answer.

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(3 marks)

1 (c) Did you repeat any of the results in your investigation?

Explain why you did or did not repeat any of your results.

Your explanation should include examples from your results.

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(3 marks)

1 (d) In your investigation you changed the area of the solar cell exposed to the light.

What was the range of this variable?

The range was from ........................................... cm2 to ........................................... cm2

If you had been able to use another value of this variable, either within or outside this

range, what value would you have chosen?

Give a reason for your answer.

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(3 marks)

1 (d) Most experiments contain errors or uncertainties.

What do you think was the cause of the largest error or uncertainty in your investigation?

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What you could do to reduce the size of this error if you were to repeat the investigation?

Explain your answer.

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(3 marks)

1 (e) You have been given the results obtained by others.

Do these other results show that this investigation is reproducible?

Your explanation should include examples from the results.

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(3 marks)

Question 2c generally asks you to look at case study 4 on the sheet and do some of the

following things:

describe the relationship between the variables, or

look at how the people who did the experiment have described the relationship and

criticise their work and say whether you agree with it or not, or

analyse some information and make and justify a prediction

say what extra evidence would be useful

When marked are dropped on the question it’s usually because of a lack of detail in the answer. To get 3 marks generally

requires a good amount of detail.

Other things that could get asked.

You should make sure that you know the following things in case you get asked about them:

The independent variable

The dependent variable

A list of control variables (and how you will control them)

The range of the independent variable you will investigate

The interval of the independent variable you will use

The meanings of the other terms on the yellow sheet in your books