Collecting Data 1 2 3 Ways of displaying

Collecting Data 1

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Ways of displaying data The information that is gathered is generally called data. The branch of Maths that deals with collecting, presenting and analysing data is called statistics. 4

Survey Way of finding information It involves asking questions, recording what people say and presenting information 5

Consider these questions: What is the most common shoe size in the class? How long does it take a group of people to walk a mile? The answers to these questions will be a number for e. g. : 25 mins or size 6 6

Data which can be counted or measured is called numerical data because the answer is a number. Numerical data can be either discrete or continuous. 7

Discrete Data: Data which can take only certain individual values is called discrete data. eg. The marks achieved in a test or shoe sizes Continuous Data: is measured on a scale and can take any value on that scale. e. g. . The heights of students in your class or temperature 8

Some answers to questions are not numbers (Word answer) This is data that fits into a group of category. For e. g. : what colour is your car? What is your favourite movie? 9

Gender Country of birth Favourite sport Favourite TV programme 10

Categorical data that has an obvious order. E. g. : type of house attendance to a concert 11

Nominal data an example of nominal data is country of birth name of a book name of your school type of car 12

Collecting Data Categorical data Nominal data ◦ or Ordinal data Numerical data Discrete data or Continuous data 13

Why do people collect data? Market Research Census Future planning 14

Primary data - collected by an organisation or an individual who are going to use it. Obtained by a questionnaire, experiment, investigations 15

Secondary data- is already available or collected by someone else. Obtained by the internet, books, magazines 16

Surveys are particularly useful for collecting data that is likely to be personal. A survey collects primary data. 17

Postal surveys Personal interviews Telephone surveys Observation 18

Advantages-organized and mechanical Disadvantages- Results are prone to chance. 19

Advantages-Many questions can be asked and easy to do Disadvantages- Expensive, Interviewer may influence responses. 20

Advantages- Relatively cheap, Large amounts of data can be collected. Disadvantages- Poor Response rate 21

Useful for collecting scientific data. Use a data capture sheet to record results Example on next slide 22

Name Age Amount Saving 23

A questionnaire is a set of questions designed to obtain data from individuals People who answer questionnaire are called respondents. 24

An interviewer asks the questions and fills in answers. People fill out the questionnaire themselves. 25

Be clear what information you want to find out Keep it simple Provide response questions Avoid personal questions or bias 26