Making Effective Graphs

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Making Effective Graphs
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Guidelines for creating an effective graph

• ? Every time you create a graph, you should
  address the following
• What is the purpose of making a graph from this
  data?
• What type of graph should you make? Pie
  Bar X-Y scatter
• Decide on a title and consider the Ws (who,
  what, where, and when)
• Legend yes no
• Descriptive x-axis label (if applicable)
• Descriptive y-axis label (if applicable)
• Scale (if applicable)
• Source of graph (add to graph using a text box)
• Does my graph stand alone?
• What story does your graph tell? What is the
  graph telling me? Dont just focus on the
  specific features of the graph!

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XY Graphs

• Use when you have a lot of data points
• Way of graphing data that changes over time
  (abortion rate, population, poverty line, price
  of stamps, etc.)
• So the x-axis will be years and the y-axis will
  be the quantity that is changing
• Use when categories along x-axis are numerical
  (e.g., seconds, minutes, years)
• When possible use relative rather than absolute
  numbers
• When labeling the x and y-axis and giving the
  chart a title, make sure you know the units.
• Dont use line graph

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Bar Charts

• Use when a quantitative variable is associated
  with a categorical variable
• X-axis is treated categorically
• Useful when you have a limited amount of data
• Useful when you want to compare more than one
  series (group)
• Years on X-axis HAVE to be consecutive!
• Use COLUMN chart type

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Pie Charts

• Use when you have categorical information (e.g.,
  ethnicity, gender, country of origin)
• Doesnt track changes over time
• ONE time period
• Quantities and categories must add up to 100
• Parts of a whole
• Categories can not overlap
• Dont include total category!
• Add labels (rounded to 2 decimals)

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How to describe your graph

• Graph should be able to stand alone
• If reader doesnt understand graph without a
  story then the graph isnt good
• Point out what you want the reader to know
• What is the graph telling me??
• Dont just mention specific features (minimum and
  maximum points)
• The goal is to
• Give a good idea of overall trends
• Point out the most interesting or surprising
  features.

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Helpful Hints

• Dont highlight blank cells
• Make sure screen size is 100 before you make a
  graph

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Legends on graphs

• Legends are added by default on bar and XY graphs
• Remove legend when only one data series
• Click and press DELETE or BACKSPACE
• When you have more than one series you MUST
  label the legend

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Adding Source Reference to Graph

• Add text box to area in graph
• Type - Source US Department of Education
• Insert tab text box
• Not adding a Source is plagiarism!