Types of GraphsDisplaying Information

What are Graphs used for?

We can present data in a graphical form as it is easier to see what is going on, or to spot patterns, rather than looking at raw numbers in a table or in a spreadsheet. Graphs are visual images which are quick and easy to read.

Raw DataRaw data is collected and recorded in a table.

Different eye Colours

A simple table is easy to read.What is the most common eye colour?

Blue Black Brown Grey Hazel Green

Class One

8 3 15 2 4 0

Types of GraphsThere are 5 main types of graphs;1. pictogram2. bar chart.3. comparative graph4. pie chart5. line graph

Pictograph• This is a simple way of representing data with a

picture. • What target market would this be good to aim

information at?

0

1

2

3

dog cat fish rabbit

Y axis

This tells us the number of pets.

X axis. This tells us the type of pets.

Pictograms - Advantages and

Disadvantages

Can you think what the advantages and disadvantages of a pictogram may be?

Advantages Disadvantages

Pictograms - Advantages and

Disadvantages

Can you think what the advantages and disadvantages of a pictogram may be?

Advantages

• Easy to read.• Quick.• Communicate

with other languages.

Disadvantages

• Simple data• Limited topics• Suits smaller

numbers unless a key/legend is used.

Pictograms - Advantages and

Disadvantages

Can you think what the advantages and disadvantages of a pictogram may be?

Advantages

• Easy to read.• Quick.• Communicate

with other languages.

Disadvantages

• Simple data• Limited topics• Suits smaller

numbers unless a key/legend is used.

Bar ChartA bar chart uses columns or blocks to show data values. This type of chart is useful for showing bigger numbers and for making quick comparisons.

Blue Black Brown Grey Hazel Green02468

10121416

Class 1

Class 1

X axis – represents the category choices, the data that does not change.

Y axis – usually represents the values that change.

Children with eye colour.

Bar ChartIs it easier or harder to read compared to the table?

Blue Black Brown Grey Hazel Green02468

10121416

Class 1

Class 1

Blue Black Brown Grey Hazel Green

Class One

8 3 15 2 4 0

Comparative ChartWhat happens if other classes are added.

Now which is the most common eye colour?Is it as easy as when it was just one class?

Blue Black Brown

Grey Hazel Green

Class One 8 3 15 2 4 0

Class Two 10 1 14 6 0 1

Class Three 18 0 3 0 1 2

Class Four 14 3 9 5 7 0

Comparative Graph• A comparative graph is used to compare sets of

data. It groups results for the same category.

Blue Black Brown Grey Hazel Green0

2

4

6

8

10

12

14

16

18

20

Class 1class 2class 3class 4

Pie ChartA pie chart is a circle made from segments. Each segment represents a proportion. The proportions of a pie chart are usually shown as a percentage.

This is a legend/key. It uses colour code to represent the different topics.

Pie Chart Advantages and

Disadvantages

Pie charts do not show exact values, but percentages. They are really useful when comparing a large sample with a small sample.

It would be difficult, as a bar chart, to compare class eye colour with a top value of 30 children to a whole school survey, where there will be over 200 answers.

Line GraphA line graph is used when the value being measured is the same. It is similar to a bar chart, but samples data at intervals.

Line graphs can track when values are high or low. One example is a weather chart, showing the sunshine or rainfall for the year. Each month would be an interval measure.

Business use line graphs to track their sales.

Graphs• Each graph type has it’s own advantages and

disadvantages. You need to think about your purpose and audience before choosing which style to use.

Can you remember the five main types of graphs?

Exam QuestionA company that makes bicycles is celebrating a successful year. They have excellent sales figures and want to use them to help promote their success. A graphic designer has been asked to produce graphs or charts that make the sales figures more visual for use in promotional graphics. The sales figuresare shown below.

Sales figures AWorldwide bicycle sales bypercentage in 2011UK Sales 37%European sales 27%USA sales 20%Australian sales 11%Sales in other countries 5%

Sales figures BMonthly bicycle sales in 2011Month Number of salesJan 1,600Feb 1,100Mar 1,200Apr 2,600May 2,200Jun 3,200Jul 5,600Aug 6,900Sept 2,400Oct 1,150Nov 1,100Dec 9,250

The Answer1a. State the name of a suitable graph for displaying the information revealed in Sales Figure A and explain your answer.

1b. State the name of a suitable graph for displaying the information revealed in Sales Figure B and explain your answer.