1 Adding a statistics package Module 2 Session 7

2 Learning Objectives Recognise the limitations of any software even Excel! Introduce statistics packages in general using Instat as a simple example Explain the reasons for adding a statistics package at this stage in the training Show how easy it is to use a statistics package hence give confidence to students that they could easily use another package later, if needed

3 Contents Review of use of Excel Problems with Excel for statistics all packages have limitations Adopting a flexible software strategy Why do more? Instat - an example of a statistics package What are statistics packages? Why were they scary? and are not now Practical, then brief discussion

4 Use of Excel for statistics Used Excel for descriptive statistics tables and graphs exploration and summary Needed an add-in for effective use Summary of EXCEL for Statistics Data manipulation very good Pivot tables very good Graphics all right Very visual environment

5 Now need to do more Process multiple response questions Produce tables, with weights Cope with missing values and zeros Excel is reaching its limits It is a jack of all trades It is serving us well We can add other software to our toolkit And still use Excel when appropriate

6 Another problem with Excel Software should give the right answer We show that Excel did not though SSC-Stat is OK Give the mean and standard deviation of: mean = 3s.d. = 1.58 What is the mean and s.d. if we add 10? mean = 13s.d. = 1.58 again * Check you understand that this is true

7 Standard deviation in Excel 2000

8 Conclusions from this problem Some statisticians argued If answers were sometimes wrong, how can you trust Excel therefore use different software for statistical applications Our view Data where you see problems are very odd You should notice when you get such odd data So continue with Excel for descriptive statistics But switch to statistical software for more complex descriptive analyses and for modelling So introduce statistics packages at this point Earlier - SSC-Stat was a first example of a very, very simple statistics package

9 Mixing software This used to be difficult for statistical applications because transferring data was messy and each package had its own commands Now it is easy Windows software is all similar Menus and dialogues replace commands These dialogues are similar in most packages And similar to those already in SSC-Stat An example of a simple statistical package

10 A familiar dialogue in SSC-Stat There are similar dialogues in any statistics package

11 So A statistics package is introduced We use new software A simple package called Instat Designed as a first statistics package And to assist in teaching concepts In Module 4 We introduce a more powerful statistics package Called STATA

12 Why Instat? A simple general statistics package and therefore easy to learn to use Designed to support teaching statistics To show the value of using the computer to support the teaching of statistics Designed as a stepping stone To show how easy it is to use any statistics package So you can easily add others (like Stata) when you need It also has a special menu for the analysis of climatic data which is a small component of this training You can distribute Instat freely in your country

13 Why Instat continued You also learn: It is easy to move from one Windows package to another This is useful in Module 4, where you will use another statistics package Once you have used two statistics packages If later, you need to use further statistics packages you should find they are simple to learn hence you no longer need a special course And you can work with partners who use different packages

14 Spreadsheet view of data Results in different type of window Names for columns Data start in row 1 Key menus are Manage, Graphics, and Statistics - compare with SSC-Stat INSTAT Windows

15 What is a statistics package? It is essentially a column calculator like Excel when the data are in list format Some results are on the previous slide Menus are like those in SSC-Stat Manage, Graphics, and Statistics in Instat Manipulation, Visualisation and Analysis in SSC-Stat (Data, Graphics and Statistics in Stata) Other aspects of Instat See details of the previous slide

16 Practical work Instat should have been installed for you It comes with a tutorial And there is an extensive demonstration The first practical gives 2 options The tutorial for those who are more experienced The demonstration for those with less experience What you choose is up to you – and your staff! And then asks for your initial views Two things you liked Two things you did not like

17 Discussion Evaluate Instat In its own right And as an example of a statistics package Also the demonstration exercise Consider Ease of use Potential for further work Advantages and limitations compared to a spreadsheet

18 Initial views on Instat What were your likes? What were your dislikes?

19 Why were statistics packages scary? Instinctive Statistics is scary, so statistics packages must be scary too! They used to be All different - and users not experienced in computers Command driven So you had to learn a language Then you were tied to one package Data was difficult to transfer between packages Now All packages are in Windows, so easy to use Data easy to move between packages All similar, so easy to use any, once one is familiar Can be used in addition to Excel

20 Objectives: Can you now: Recognise all software has limitations even Excel!! Explain the reasons for adding a statistics package at this stage in the training See how easy a statistics package is to use hence have confidence that you could easily use another statistics package later, if needed