Post on 22-Jan-2016
description
Data types and representationData types and representation
Two types of data:
Observations are a finite, countable,
number of values
Observations are a finite, countable,
number of values
Discrete
Observations can take on any
number of the countless number
of values in
an interval
Continuous
eg. Number of “sixes” after 3 throws of the dice
eg. The average IQ of ten random Heads of Department
Data types and representationData types and representation
Types of measurementsNominal
Objects are named and assigned to classes
eg. male or female
Ordinal
Objects are either greater, or smaller than, a comparative object
eg. finishing positions in a race
Ratio level
Basic standard interval exists + meaningful zero
eg. mass
Interval level
Basic standard interval is introduced, but no true zero
eg. temperature in celsius
Data types and representationData types and representation
Summarising
discrete data:
Name Eye ColourJanice brown
Tom blue
Danielle green
Ian brown
Eduardo brown
Emily brown
Anja blue
Cara brown
Adrian brown
Eric blue
Sarah brown
David brown
Data types and representationData types and representation
Summarising
discrete data:Frequency tables
Eye Colour Frequency
Brown
Blue
Green
33
14
3
Data types and representationData types and representation
Summarising
discrete data:
Eye Colour FrequencyRelative Frequency
Brown
Blue
Green
33
14
3
66%
28%
6%
Frequency tables
Data types and representationData types and representation
Summarising
discrete data:
Frequency bar graph
Data types and representationData types and representation
Summarising
discrete data:
Relative frequency bar
graph
Data types and representationData types and representation
Summarising
continuous data:
Name
Hours of
Sleep / NightJanice 6
Tom 7.5
Danielle 10.5
Ian 9
Eduardo 7
Emily 6
Anja 8
Cara 5
Adrian 8.5
Eric 6.5
Sarah 7.5
David 4
Data types and representationData types and representation
Hours of Sleep Frequency
3 - 4 hrs
4 - 5 hrs
5 - 6 hrs
6 - 7 hrs
7 - 8 hrs
8 - 9 hrs
9 - 10 hrs
10 - 11 hrs
1
3
6
14
16
5
3
2
Summarising
continuous data:
Frequency tables
Data types and representationData types and representation
Summarising
continuous data:Frequency bar graph
(Histogram)
0
5
10
15
20
3.5 4.5 5.5 6.5 7.5 8.5 9.5 10.5
Nightly hours of sleep
Fre
qu
ency
Data types and representationData types and representation
Summarising
continuous data:
Relative frequency bar chart
0
10
20
30
40
3.5 4.5 5.5 6.5 7.5 8.5 9.5 10.5
Nightly hours of sleep
Fre
qu
ency
(%
)
Data types and representationData types and representation
Summarising
continuous data:
Line graph
Data types and representationData types and representation
Summarising
continuous data:
Scatter graph