1 7
AUTHORING AP H D60
Respondents saying government is doing a good job (%)
50 40 30 20 10
J
J
J
A
S
O
N
D
F
M
A
M
Month of the year Good job’
Smoothed good job’
0
(f)
Line graphProportion of the UK survey respondents seeing their governments as doing a good job in 2001 (hypothetical)Use a line graph chart whenever you have continuous overtime data.
Don’t use line graph charts if the data are overtime but are not really continuous you have very few observations in both these cases use a vertical bar chart.
Points to watch
if you have more than one line, make sure that they are each visible.
HANDLING ATTENTION POINTS 10
J
F
M
A
M
J
Month
Percentage
% Very good Fairly good’
J
A
S
O
N
D
0
(g)
Layer chartProportion of UK survey respondents rating the performance of the railways as very good orb bfairly good, 2001 (hypothetical)Use a layer chart whenever you want to show how the relative size of two positively associated variables varies across time.
Don’t use a layer chart if your two variables are not really linked.
Points to watch put the layers in an order that gives
the clearest visible pattern, e.g. a numerical progression with the largest layer at the bottom and smaller layers towards the top if the variables have to be kept in a fixed sequence but this gives a jumbled
appearance to the layers, then use another type of chart.
1 8 AUTHORING AP H D 45 Customer satisfaction (%)
35 30 25 20 15 10 0
2 Flights delayed (%)
8 10 12 14 5
0
(h)
Scatterplot or X and Y graphShare with your friends: