Data 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 representation Types of measurements Nominal 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 representation Summarising discrete data: NameEye Colour Janicebrown Tomblue Daniellegreen Ianbrown Eduardobrown Emilybrown Anjablue Carabrown Adrianbrown Ericblue Sarahbrown Davidbrown

Data types and representation Summarising discrete data: Frequency tables Eye Colour Frequency Brown Blue Green

Data types and representation Summarising discrete data: Eye Colour Frequency Relative Frequency Brown Blue Green % 28% 6% Frequency tables

Data types and representation Summarising discrete data: Frequency bar graph

Data types and representation Summarising discrete data: Relative frequency bar graph

Data types and representation Summarising continuous data: Name Hours of Sleep / Night Janice6 Tom7.5 Danielle10.5 Ian9 Eduardo7 Emily6 Anja8 Cara5 Adrian8.5 Eric6.5 Sarah7.5 David4

Data types and representation Hours of Sleep Frequency hrs hrs hrs hrs hrs hrs hrs hrs Summarising continuous data: Frequency tables

Data types and representation Summarising continuous data: Frequency bar graph (Histogram)

Data types and representation Summarising continuous data: Relative frequency bar chart

Data types and representation Summarising continuous data: Line graph

Data types and representation Summarising continuous data: Scatter graph