Adding a statistics
package
Module 2 Session 7
1
Learning Objectives

Recognise the limitations of any software


Introduce statistics packages in general


using Instat as a simple example
Explain the reasons for adding a statistics
package


even Excel!
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
2
Contents


Review of use of Excel
Problems with Excel for statistics






Adopting a flexible software strategy
Why do more?
Instat - an example of a statistics package
What are statistics packages?
Why were they scary?


all packages have limitations
and are not now
Practical, then brief discussion
3
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


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Data manipulation very good
Pivot tables very good
Graphics all right
Very “visual” environment
4
Now need to do more

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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
5
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:
1

3
4
mean = 3
5
s.d. = 1.58
What is the mean and s.d. if we add 10?
11
*
2
12
13
14
mean = 13
15
s.d. = 1.58 again
Check you understand that this is true
6
Standard deviation in Excel 2000
7
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
8
Mixing software

This used to be difficult



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Now it is easy




for statistical applications
because transferring data was messy
and each package had its own commands
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
9
A familiar dialogue in SSC-Stat
There are
similar
dialogues in
any statistics
package
10
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
11
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
12
Why Instat continued

You also learn:
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Once you have used two statistics packages

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It is easy to move from one Windows package to
another
This is useful in Module 4, where you will use another
statistics package
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
13
INSTAT Windows
Key menus are Manage, Graphics, and Statistics - compare with SSC-Stat
Names for
columns
Data start
in row 1
Spreadsheet
view of data
14
Results in different type of window
What is a statistics package?

It is essentially a column calculator


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Menus are like those in SSC-Stat
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Manage, Graphics, and Statistics in Instat

Manipulation, Visualisation and Analysis in SSC-Stat
(Data, Graphics and Statistics in Stata)


like Excel when the data are in “list format”
Some results are on the previous slide
Other aspects of Instat

See details of the previous slide
15
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

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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
16
Discussion

Evaluate Instat

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In its own right
And as an example of a statistics package
Also the demonstration exercise
Consider


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Ease of use
Potential for further work
Advantages and limitations

compared to a spreadsheet
17
Initial views on Instat
 What
were your likes?

What were your dislikes?
18
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

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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
19
Objectives:


Can you now:
Recognise all software has limitations


Explain the reasons for adding a statistics
package


even Excel!!
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
20