How to choose the right graphic for your data.

1. WHICH GRAPHIC TO USE
How to Choose

2. there are three main types of graphic

3. bar chart pie chart line graph

4. all three are used to display
different kinds of data

5. let’s have a look at some examples

6. using a class of
30 students

7. and information about their
social media use

8. BAR
CHARTS

9. bar charts are good for
showing discrete categories
of data

10. let’s say we wanted to find
out which social media apps
they use

11. so we ask them to answer a
survey telling us which apps
they use

12. it should give us a table that
looks like this

13. Snapchat 19
Twitter 21
Instagram 17
Facebook 12
Other 11

14. as the total is more than 30,
we can see that most of them
use more than one app

15. Snapchat 19
Twitter 21
Instagram 17
Facebook 12
Other 11
Total = 80

16. if we add all the responses
together, we get more than 100%

17. this means the people who use
each app are a discrete group

18. if the number of people using
one app increases, it doesn’t
mean the number of people
using other apps goes down

19. Snapchat 26
Twitter 21
Instagram 17
Facebook 12
Other 11

20. because we want to compare
how may people use each app

21. we need to display the
information in a bar chart

22. 0
10
20
30
Snapchat Twitter Instagram Facebook Other

23. PIE
CHARTS

24. pie charts are good when we
want to show parts of a whole

25. now, let’s say we wanted to
find out which app they use
the most

26. so we ask them to answer
another survey, telling us their
favorite app

27. we should get a table that
looks like this

28. Snapchat 9
Twitter 14
Instagram 3
Facebook 2
Other 2

29. this time, because each person
only selected one app, we have
a closed group of 30 responses

30. so when we add the different
subgroups together, we get 100%

31. this means we can consider
each subgroup a percentage of
the whole class

32. so we need to display the
information in a pie chart

33. 7%
7%
10%
30%
47%
Twitter
Snapchat
Instagram
Facebook
Other

34. LINE
GRAPHS

35. line graphs are used to show
how things change

36. usually over time

37. the surveys we’ve done so far
don’t show us any kind of change

38. but let’s say we wanted to see
how the results changed

39. we could do one of the same
surveys repeatedly

40. so let’s say we ask them to
answer the survey about their
favorite app

41. and we ask them at the
beginning of every year

42. we’d get a table that looks like this

43. 2014 2015 2016 2017
Snapchat 2 3 3 9
Twitter 10 14 19 16
Instagram 4 5 3 3
Facebook 14 8 5 2

44. now we can see that people’s
favorite app has changed over time

45. and we can show this with line graph

46. 0
5
10
15
20
2015 2016 2017 July
Snapchat Twitter Instagram Facebook

47. so all three kinds of chart
show different kinds of data

48. bar chart pie chart line graph
discrete
groups
parts within
a whole
change over
time

49. now you know which one to use

50. END