SADC Course in Statistics Good graphs & charts using Excel Module B2 Sessions 6 & 7

To put your footer here go to View > Header and Footer 2 Learning Objectives students should be able to Understand the terminology –used to identify different parts of a chart Recognise parallels between tables and charts Decide which type of graph –is appropriate for displaying the information effectively Produce graphs from summaries & raw data Improve a chart –by judicious choice of type, arrangement and formatting

To put your footer here go to View > Header and Footer 3 Why do we need graphs? Charts are visual representation of the data and so are easier to digest Charts give a concise way of conveying information Are useful for highlighting key points, patterns and differences

To put your footer here go to View > Header and Footer 4 Graph overview Plot area Chart area Gridlines

To put your footer here go to View > Header and Footer 5 Graph overview value axis Legend chart title series data labels category axis

To put your footer here go to View > Header and Footer 6 Overview - some Excel chart types Excel has facilities to provide many types of graphs out of which the most common for categorical variables are: »Column charts »Bar charts »Pie chart

To put your footer here go to View > Header and Footer 7 Choice in type of graphs

To put your footer here go to View > Header and Footer 8 Where appropriate Column charts and bar charts –Useful for showing quantities in categories –stacked column & bar charts can show relative proportions in categories Pie charts –Useful for showing proportions of the whole Terminology ExcelOften called Bar chart Horizontal bar chart Column chartBar chart

To put your footer here go to View > Header and Footer 9 Using the Chart wizard Create data –possibly by typing –have the column of categories on the left –then the frequencies or proportions Select the two columns Choose chart –from the menu –or click on the Chart wizard icon –and follow the instructions * The chart wizard demonstration shows the process

To put your footer here go to View > Header and Footer 10 Editing the Chart Click in the chart –to edit the corresponding element Use good practice for charts to –Select appropriate graph type –Select suitable colours, fonts and style –Change the scales for the axes –Add titles and units –Edit and position legend –Change borders and fill effects

To put your footer here go to View > Header and Footer 11 Practical 1 Activity 2 uses CAST For bar charts, stacked bar charts and pie charts Activity 3 shows how to construct and edit a simple chart Activity 4 shows how to display different types of data on the same chart Activity 5 gives practice Note any interesting points and difficulties at the end of the practical for discussion later

To put your footer here go to View > Header and Footer 12 Comparing pie charts and bar charts Bar charts better to compare single categories Pie charts good when multiple categories combined

To put your footer here go to View > Header and Footer 13 Cumulative counts and percentages Particularly useful for ordered variables

To put your footer here go to View > Header and Footer 14 Pie charts Multiple pie charts can be useful but consider stacked bar charts as an alternative

To put your footer here go to View > Header and Footer 15 Horizontal bar charts – when labels are long

To put your footer here go to View > Header and Footer 16 Using Pivot tables & charts Usually start with the raw data and need both a table and a graph Use the pivot table facility, –go to the raw data –produce a frequency table using Pivot tables See Activity 3 in the last session Click on chart icon –in the Pivot toolbar and follow instructions

To put your footer here go to View > Header and Footer 17 Practical 2 Activity 6 uses the data on the fundamental principles Activity 7 uses the Tanzania data What positive points can you say about Excels graphics? Did you have any problems? What negative points do you have?

To put your footer here go to View > Header and Footer 18 Pie chart What percentage of households ate meat one time or less? What other questions did you give?

To put your footer here go to View > Header and Footer 19 Summary Graphs & charts –give a visual presentation of your results A good graph –is simple, uncluttered –and has all the essential information Graphs can be produced using the chart wizard directly –or through the pivot table facility Select a chart which is suitable –for the type of presentation one is dealing with.

To put your footer here go to View > Header and Footer 20 Now you know how to construct good tables and good graphs the next session shows how to improve existing presentations