Teach GCSE Maths

Collecting DataCollecting Data

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Collecting Collecting DataData

The word survey can be used for several methods of collecting data.

Can you and your partner think of advantages and disadvantages of the methods given below for getting the required data ?

1. A face-to-face survey, on the street, to find out which TV programmes were watched the previous day.

2. A postal survey to gather views on traffic in a town.

Purpose of Survey

Advantages Disadvantages

Face-to-face

Choice of TV programmes

PostalViews on Traffic

Cheap.

People often do not reply and the answers may not reflect all opinions.

Expensive.

Questions can be explained.Data can be collected while people still remember.

Here are some possibilities. You may have thought of others.

Not random.

In these presentations we have also seen data that has been collected by the following methods:

• experiment• direct observation

• using recordsOne other way to collect data is to use a data

logger. These record data over a period of time using a sensor.

Surveys can also be carried out by telephone or using the internet. They use questionnaires to collect the data.

This is a picture of an old wind gauge.

Ans:

C. Do an experiment and record results.

A. Direct observation.

B. Refer to records.

E. Use a questionnaire.1. To find the average daily maximum

temperature in London in June.

D. Use a data logger.

Decide with your partner which of the methods A, B, C,D or E you would use to collect data for the investigations described below.

B

B. Refer to records.

Ans:

C. Do an experiment and record results.

A. Direct observation.

B. Refer to records.

E. Use a questionnaire.2. To find the best soil conditions for

germination of seeds.

D. Use a data logger.

Decide with your partner which of the methods A, B, C,D or E you would use to collect data for the investigations described below.

C

C. Do an experiment and record results.

Ans:

C. Do an experiment and record results.

A. Direct observation.

B. Refer to records.

E. Use a questionnaire.3. To find the age distribution of cars in a

town.

D. Use a data logger.

Decide with your partner which of the methods A, B, C,D or E you would use to collect data for the investigations described below.

A

A. Direct observation.

Ans:

C. Do an experiment and record results.

A. Direct observation.

B. Refer to records.

E. Use a questionnaire.4. To find out what types of transport

students use to get to a school.

D. Use a data logger.

Decide with your partner which of the methods A, B, C,D or E you would use to collect data for the investigations described below.

E

E. Use a questionnaire.

Ans:

C. Do an experiment and record results.

A. Direct observation.

B. Refer to records.

E. Use a questionnaire.

D. Use a data logger.

5. To monitor a patient’s heart rate in hospital.

Decide with your partner which of the methods A, B, C,D or E you would use to collect data for the investigations described below.

D

D. Use a data logger.

A census gets data from all the people or things that are being studied.

The National Census is a survey of all the people and households in the UK and has taken place every 10 years since 1801.

Everyone in the UK is asked the same questions on the same day and the answers allow the government to plan housing, education, health and transport services.

Most of the time a sample is quite enough . . .

A census is very expensive. The 2001 census covered 30 million households.

There are millions of forms to be delivered and collected.

and sometimes a sample is the only way to find out information.

The life-time of batteries could be tested by taking a sample of 100 batteries and using them to see how long they last.

If they used all the batteries they wouldn’t have any to sell !

Surveys usually involve taking a sample.

SUMMARY

The National Census is a survey covering such things as age, gender, work, health and housing. It is carried out every 10 years for all the people living in the UK.

Data can be collected by • direct

observation • experiment • using records • using a data logger • a survey using a questionnaire

A census is a survey of all the people or things that are to be studied.

Advantage

Disadvantage

(a) telephone

(b) door-to-

door

Exercise

1. Write down one advantage and one disadvantage of the following ways of collecting data for a survey:(a)by

telephone(b)door-to-

doorSolution:

It is cheap.

Certain groups of people may not have telephones.

Questions can be explained.

Some people will be out or unwilling to speak to the interviewer.In both (a) and (b) the disadvantages given

here could lead to a sample that does not represent all opinions.There are lots of other good

answers.

Exercise2. From the list below write down a suitable

method for collecting data for each of the following investigations:(a) To find out the amount of money

students at a university spend on magazines. (b) To discover which of 3 varieties of tomatoes give the highest yield.

(c) To find out how many birds visit a particular patch of woodland.

D. Do an experiment and record results.

A. Direct observation.B. Refer to records. E. Use a

questionnaire.C. Use a data logger. Solutio

n:(a) E (b)

D(c) A