SR120 Introduction to Data Analysis and Research Methods

1
SR120 Introduction to Data Analysis and Research
Methods

• Lecture 7
• Presentation of Data Basic Concepts

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Aims

• To revise Levels of Data and discuss how each
  should be displayed
• To introduce basic ways of Presenting Data
• To introduce basic guidelines when Presenting
  Data
• To introduce the concept of Independent and
  Dependent Variables

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Levels of Data

• Nominal
• Ordinal
• Interval
• Ratio

• What was wrong with
• A New View of Statistics http//www.sportsci.org
  
• Data and Variables
• A Hitch Hikers Guide to Statistics on the
  Intranet
• Analysing Your Data

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Simple Ways of Presenting Data

• Tables
• Pie Charts
• Bar Graphs
• Column Graphs
• Line Graphs
• Histograms
• Frequency Polygons

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Tables

• Tables shouldnt contain too much or too little
  information
• Use either a Table or a Graph, not both
• Use a Table in preference to a graph when
• The reader needs to know the actual numbers
• There is no interesting trend in the data
• There are too many variables to fit on a graph

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Pie Charts

• Suitable for Nominal Level Data
• Can be shown with or without percentages
• (Segment/Total)x100
• Can be 3D with slices removed etc.

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Bar and Column Graphs

• Generally suitable for any Level of Data
• Bars - horizontal
• Columns - vertical
• Good for looking at comparisons or differences
• Include one Independent Variable

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Column Graphs

• Use of two Independent Variables
• Gender
• Age
• Use of one
• Dependent Variable
• Distance Jumped

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Line Graphs

• Generally suitable Interval or Ratio Levels of
  Data
• Good for looking at changes over time
• Can include one or two Independent Variables

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Histograms

• Used for Nominal Level Data
• Used to represent the distribution of a large
  amount of data on one variable
• Constructing a Histogram
• Find Range
• High Score - Low Score
• Decide number of Intervals
• Usually about 15
• Calculate the Interval Size
• Range/15
• Round to an Integer
• Tally scores in each Interval

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Frequency Polygons
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Preparation for Next Week

• Recommended Reading
• Vincent (1999)
• Chapter 2
• Thomas and Nelson (1996)
• pages 399-407

• Tasks on the Student Intranet
• All graphs in this lecture in Tasks for Lec. 6
  Solutions
• Tasks for Lecture 7
• One in MS Excel
• One in MS Word