SADC Course in Statistics Presenting good tables and graphs Module B2, Session 8

To put your footer here go to View > Header and Footer 2 Learning Objectives students should be able to Provide some principles that characterise good tables and graphs Use these principles to recognise examples of good practice Suggest reasoned improvements for tables and charts Provide examples of improved presentations Be able to extract key points from a table or graph for a talk or a report

To put your footer here go to View > Header and Footer 3 Contents First practical: reading CAST group work that also practices teaching skills Discussion of the principles Of good tables And good graphs Notes added to the practical sheet Second practical Putting the principles into practice Also continues the group work and discussion

To put your footer here go to View > Header and Footer 4 Practical 1 Work in groups of between 2 and 4 Read CAST page as a group agree on the main point and write it in the practical sheet The remaining pages from CAST are divided Read your page(s) carefully and make notes on the key points Present your page(s) to the others so they can work just from the tables and graphs your explanations are instead of the text

To put your footer here go to View > Header and Footer 5 Discussion of principles A class discussion to give a list of principles for tables and graphs They are noted in the practical sheet Some examples are evaluated using these principles Suggest improvements Suggest comments for the text Examples are given on the next slides

To put your footer here go to View > Header and Footer 6 UN report on principles – Table 1

To put your footer here go to View > Header and Footer 7 Points on the table Layout is reasonably clear But – CAST has the following suggestions: Because the columns of frequencies and columns of percentages are not adjacent, comparisons are harder. A better format for the table groups together the columns of related values and separates these groups with white space. We have also made improvements to the column headings and replaced the first two rows of the table with the country categories Least developed and Other developing to form a standard frequency table.

To put your footer here go to View > Header and Footer 8 Suggested improved layout

To put your footer here go to View > Header and Footer 9 Table 2 from UN survey report What improvements can you suggest?

To put your footer here go to View > Header and Footer 10 Reflection and preparation There are more tables in Practical 2 for you to discuss and improve Now look at some graphs Some are of new types, but the same principles apply The next 4 slides show an impressive chart It may not look much like statistics But it was prepared by the UN Statistics Division! Then graphs and text together From UN MDG update for Africa Then more graphs From UN Disaster report 2004

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To put your footer here go to View > Header and Footer 17 Aids and HIV prevalence

To put your footer here go to View > Header and Footer 18 UNDP – Reducing disaster risk from

To put your footer here go to View > Header and Footer 19 Pie charts from UNDP disaster report

To put your footer here go to View > Header and Footer 20 Chart clutter As mentioned many times every aspect of a chart must have a function. Including unnecessary features can distract from the point More worryingly they can also mislead Look at the pie chart on the next slide and assign a (rough) percentage value to each “slice”.

To put your footer here go to View > Header and Footer 21 3D pie chart: from the Tanzania Survey

To put your footer here go to View > Header and Footer 22 Compare a few of the classes answers in a table on the board. Cereals Roots and tubers Pulses Fruit and vegetables Cash crops 0% Oilseed 0%

To put your footer here go to View > Header and Footer 23 Pie chart with values included

To put your footer here go to View > Header and Footer 24 Surprised? Did you estimate the 3 smallest pieces to be of the same size? Making graphs 3D is one of the most dangerous adaptations you can do. It reduces the clarity of the chart and leads to misinterpretations. The purpose of a chart is to provide clear visual illustrations of your analysis. It is the message that is important not the “look”.

To put your footer here go to View > Header and Footer 25 Practical 2 CAST suggested improvements for table 1 in the UN report on statistical principles and in official tables from New Zealand Improvements can be suggested wherever the report is from! The report of the Tanga region may have a 2 nd edition Tables and charts are given from this report Share them between you Suggest improvements Suggest points that can be made in the text Discuss with others in your group

To put your footer here go to View > Header and Footer 26 Finally: Are you now able to Provide some principles that characterise good tables and graphs Use these principles to recognise examples of good practice Suggest reasoned improvements for tables and charts Provide examples of improved presentations Be able to extract points from a table or graph for a talk or a report

To put your footer here go to View > Header and Footer 27 Sessions 4 to 8 have considered how to produce good tables and graphs, once the data are ready for the analysis The next sessions look at how to prepare the data so it is ready for the analysis