# SADC Course in Statistics Session 4 & 5 Producing Good Tables.

## Presentation on theme: "SADC Course in Statistics Session 4 & 5 Producing Good Tables."— Presentation transcript:

SADC Course in Statistics Session 4 & 5 Producing Good Tables

To put your footer here go to View > Header and Footer 2 Learning Objectives students should be able to Explain the properties of a table and their role in the data analysis process Produce a frequency table by hand and using Excel Pivot Tables Produce a table with counts, proportions & percentages Improve a table Hide, re-order and merge categories in a table Display tables with an appropriate format, and with or without the margins

To put your footer here go to View > Header and Footer 3 Contents Examples of one-way tables Why do we need tables Practical 1 – CAST for one-way tables Tables by hand tables of counts, proportions and percentages Discussion Practical 2 Pivot tables in Excel Discussion

To put your footer here go to View > Header and Footer 4 Example 1 – a one-way table Sources of drinking water for households in rural Tanzania in 2002/3 Two summary statistics Counts and percentages Table margin (gives totals)

To put your footer here go to View > Header and Footer 5 Example 2 - also a one way table TB cases in SADC countries in 2005 Three summary statistics

To put your footer here go to View > Header and Footer 6 Example 3 – Responses to survey Response rates for UN survey on the principles of official statistics Twelve summary statistics! (Not six?)

To put your footer here go to View > Header and Footer 7 Example 4 – the principles adopted? Nine one-way tables – still in Excel Percentages Counts How could you deduce the individual counts?

To put your footer here go to View > Header and Footer 8 Same information – in a graph Tables first – later sessions look at graphs

To put your footer here go to View > Header and Footer 9 A 2-way table Two-way because 2 factor (categorical) variables Type of country (3 levels) and Principle 4 (4 levels) The table margins of a two-way table are one-way tables In this course we mainly cover one-way tables

To put your footer here go to View > Header and Footer 10 Why do we need tables? Data checking and data cleaning To capture the information in the data and summarize it in different ways Reference tables in appendices Presentation of results

To put your footer here go to View > Header and Footer 11 Types of tables One-way Tables –How often does a particular variables category occur? Two-way tables (or higher) –What is the relationship between two (or more) categorical variables? –How often does a particular variable occur at each combination of category levels Type of table depends on type of data & the question being answered We concentrate here largely on 1 way tables

To put your footer here go to View > Header and Footer 12 A one-way table.. Frequency tables can be made using –tallies ( by hand or with computer) –using the pivot table facility in Excel Frequency table can be made to –show counts – actual frequencies –Proportions – relative frequencies –Percentages- proportions multiplied by 100; easier to compare

To put your footer here go to View > Header and Footer 13 A one-way table As an exploratory tool, can be used to –give overall frequency distribution –reveal incorrect categories –reveal categories with few observations As a presentation tool, can be used to –summarize results and interpret the findings so that it highlights the key features of the data

To put your footer here go to View > Header and Footer 14 Formatting Suitable formatting and displaying can make a lot of difference to the readability of the table, one should consider: –Number of decimal places –Spacing –Alignment –Ordering of categories –Merging of groups –Labelling of groups –etc

To put your footer here go to View > Header and Footer 15 Practical 1 Use CAST to learn more about tables A simple way to get a frequency table is to tally the numbers in each category by hand enter the summary data into Excel and work out the proportions and percentages from the frequencies These are activities 2 to 5

To put your footer here go to View > Header and Footer 16 Discussion of Practical 1 – activity 2 This layout is the usual one Thats because surveys have a lot of questions Here you can process each variable in turn

To put your footer here go to View > Header and Footer 17 Activities 3 and 4 Was the demonstration useful? What points were new to you, if any? Report on your results at the end of activity 4 a – this is a frequency or count b – this percentage is just 100 – 22.7 = 77.3 c – this is just the percentage divided by 100 d – this is a conditional question. The answer is 100*(13.6/(13.6+27.2))=33% or 1/3

To put your footer here go to View > Header and Footer 18 Activity 5 What did you reply for your country on principle 1? What were your responses on a b c – not possible with a 1-way table – 2-way table below d – not possible with a 1-way table – 2 way table below

To put your footer here go to View > Header and Footer 19 Tables from the raw data So far you have tallied by hand To get the counts or frequencies And then used Excel to get proportions and percentages Now you start with the raw data And use Excels pivot-tables To do the whole process There is a demonstration to start you off

To put your footer here go to View > Header and Footer 20 Practical 2 The usual way of making tables with Excel Uses the pivot-table wizard This is explained in the demonstration Using Pivot Tables. First watch the demonstration That is Activity 5 Then practice the skills with a second data set These are Activities 6 to 8

To put your footer here go to View > Header and Footer 21 How easy were these tasks? NoTaskHow easy? Comment 1 Order of categories 2 Name of category 3 Percentage instead 4 Format data 5 Frequency and percentage 6 Hide a field 7 Interpret a percentage 8 Hide a margin 9 Merge levels

To put your footer here go to View > Header and Footer 22 Summary One-way tables are a useful tool for presenting summaries on the categories of a single variable. Tables can be made by hand or by using special software facilities e.g. Pivot table Wizard in Excel Appropriate formatting and display is used to present the summary effectively

To put your footer here go to View > Header and Footer 23 The next 2 sessions are similar to these, but on how to produce good graphs (charts)