Charting with Excel

Overview

• Why use charts• Terminology• Chart types• Creating a chart• Modifying a chart• Avoiding common mistakes

Why use charts?

• Assist understanding of data

Monthly Sales, 2002 & 2003

Month 2002 2003Jan 94,640 57,894Feb 96,096 66,394Mar 111,552 88,816Apr 84,448 79,840May 75,712 71,093Jun 61,152 75,520Jul 50,960 73,098Aug 59,696 70,930Sep 99,008 85,904Oct 108,832 97,552Nov 122,112 100,464Dec 117,936 110,656

Monthly sales

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

Jan

Feb

Mar

Apr

May Jun

Jul

Aug Sep Oct

Nov

Dec

Month

Sal

es (

£) 2002

2003

When to use a chart

• Compare item to other items (student numbers for different departments)

• Compare data over time(student numbers since 1980)

• Make relative comparisons (proportion labour, tory, lib dem, green, other)

• Compare data relationships (marketing expenditure/student numbers)

Terminology

Monthly sales

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Month

Sal

es (

£)

2003

2002

Data points (bars, lines, columns, sectors, points)

Series (data points which come

from same row or column)

Value axis (y-axis)

Category axis (x-axis)

Legend

Scale (min, max, increments)

Gridlines (major & minor)

Column & Bar charts

• Column (vertical) • Bar (horizontal)• Use to compare discrete items

(people, countries, days)• For category data

Student numbers by department

Department No of studentsYoga 98Sanscrit 132Theology 79Music 165Dance 203

0

50

100

150

200

250

Yoga Sanscrit Theology Music Dance

No of students by department

0

50

100

150

200

250

Yoga Sanscrit Theology Music Dance

No of students by department

0 50 100 150 200 250

Yoga

Sanscrit

Theology

Music

Dance

No

Line charts

• For plotting continuous data • Useful for trends over time or distance

Student numbers by year

Department 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003Yoga 98 99 80 82 98 103 105 111 103 98 78 85 90 92Sanscrit 132 140 135 154 149 150 157 160 167 172 170 173 175 184

Student numbers since 1990

0

20

40

60

80

100

120

140

160

180

200

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

Year

No Yoga

Sanscrit

Area chart

• Like a line chart, coloured in below• May be stacked

Student numbers since 1990

0

20

40

60

80

100

120

140

160

180

200

1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003

Year

No Sanscrit

Yoga

XY Scatter

• To plot two numeric data series against each other

• Can add trend line

Marketing expenditure and student numbers

Year Marketing Student Numbers1990 10,034£ 89531991 14,065£ 11271992 13,062£ 90531993 15,425£ 110451994 19,373£ 134561995 19,476£ 130251996 12,045£ 100021997 15,925£ 128521998 17,630£ 134621999 17,492£ 140252000 13,953£ 124852001 10,348£ 92402002 11,543£ 99782003 18,245£ 12004

Marketing expenditure and student numbers

8000

9000

10000

11000

12000

13000

14000

15000

£10,000 £12,000 £14,000 £16,000 £18,000 £20,000

Marketing expenditure

Nu

mb

er o

f st

ud

ents

Pie

• For one series only • Compare contribution of different

components

Voting intentions

34%

13%31%

2%

20%

Labour

Lib Dems

Conservative

Green

Monster Raving Loonies

Voting intentions

Party 1997Labour 34Lib Dems 13Conservative 31Green 2Monster Raving Loonies 20

Doughnut

• Like a pie chart, for two series

Voting intentions

Party 1997 2003Labour 34 8Lib Dems 13 6Conservative 31 5Green 2 1Monster Raving Loonies 20 80

Voting intentions

34%

13%31%

2%

20%

8%

6%

5%

1%

80%

Labour

Lib Dems

Conservative

Green

Monster Raving Loonies

Paper exercise (5 minutes)

• Select (and sketch) an appropriate chart type…

Avoiding common mistakes

Mistakes: Plotting data out of context

Sales

0

20,000

40,000

60,000

80,000

100,000

120,000

Mar Apr May Jun Jul

£

Sales

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

£

Mistakes: Misleading scale

I ncomeJan 103,522.33£ Feb 102,054.26£ Mar 101,876.59£ Apr 102,356.77£ May 103,453.22£ J un 104,589.07£ J uly 105,563.45£ August 105,321.11£ September 104,579.56£ October 103,432.22£ November 102,364.79£ December 101,643.33£

Income

£ 99,000.00

£ 100,000.00

£ 101,000.00

£ 102,000.00

£ 103,000.00

£ 104,000.00

£ 105,000.00

£ 106,000.00

Income

£ -

£ 20,000.00

£ 40,000.00

£ 60,000.00

£ 80,000.00

£ 100,000.00

Mistakes: Aspect ratio

Sales

0

20,000

40,000

60,000

80,000

100,000

120,000

Mar Apr May Jun Jul

£

Sales

0

20,000

40,000

60,000

80,000

100,000

120,000

Mar Apr May Jun Jul

£

Mistakes: Category chart for value data

Height vs age

0

10

20

30

40

50

60

70

80

90

100

0 3 6 9 12 18 24

Age (months)

Hei

gh

t (c

m)

Girl ave. height (cm)

Boy ave. height (cm)

Height vs age

0

10

20

30

40

50

60

70

80

90

100

0 6 12 18 24

Age (months)

Hei

gh

t (c

m)

Girl ave. height (cm)

Boy ave. height (cm)

Mistakes: Too many slices of pie

Monthly sales

Month

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Monthly sales

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Mistakes: Complexity

0

5000

10000

15000

20000

25000

30000

Bev

erag

es

Con

dim

ents

Con

fect

ions

Dai

ry P

rodu

cts

Gra

ins/

Cer

eals

Mea

t/P

oultr

y

Pro

duce

Sea

food

Buchanan

Callahan

Davolio

Dodsworth

Fuller

King

Leverling

Peacock

Suyama

Drop Page Fields Here

Sum of Price

Category

Employee

Mistakes: Insufficient labelling

• Chart title

• Axis labels

• Units

• Legend

• Legibility