These notes are prepared to help you start to use the MINITAB Statistics package at the University of Leeds.
Accessing Library Files on the Leeds University Computer System
Placing MINITAB output into Word
Last updated 13 September 2002
MINITAB is one of many packages now available for performing statistical calculations. Other Statistics Packages commonly used include SAS, SPSS, GLIM and Splus (and its free equivalent R).
Many spreadsheets such as EXCEL have built-in statistical commands and have some advantages over the use of a statistical package for manipulating data. However, the range and flexibility of the statistical facilities make them poor tools for teaching statistical concepts. Therefore, we use MINITAB at the introductory levels because of its convenience as a teaching tool.
We are using Version 13, which is available on Windows XP machines linked
to the University's computing system.
On the Windows XP system MINITAB can be launched from the Start menu. Click on this, then select Programs, then Statistics and finally MINITAB 13.
When MINITAB opens we get a window which looks similar to the following:
The window has two components:
Data Window - in which the data are visible and can be edited.
There are other windows that can be reached via the Project Manager tool bar (the right-hand part of the tool bar). These include:
History - in which the full history of commands issued is stored.
The MINITAB worksheet comprises a set of cells, into each of which a value may be stored. The cells are organised into columns, which are inherently labelled C1, C2, C3, etc.
Columns are usually associated with variables. Each column comprises an arbitrary number of cells, which are considered as rows and are usually associated with observations.
Outside the column and row worksheet structure, a series of cells (termed constants) are inherently labelled K1, K2, K3, etc. and addressed as such. Finally, a series of matrices may be specified. These are labelled as M1, M2, M3, etc. and addressed as such.
Columns can be given a name by entering text into the cell at the top
of the column, above the first row.
Performing Calculations in MINITAB
Instructions to the package can be entered either by typing the command (which is often easier for simple commands once you know the commands) or using the drop-down menus. It is probably easier to do calculations using the latter in the early stages and when you are not sure of the command.
The two alternatives are
Commands to perform calculations can be very simply done using the drop-down menus. The Menu Bar allows access to various sub-menus that are grouped by subject. They are summarised as follows.
An Example
To set up the descriptive statistics command, which gives a set of simple summary statistics, click on Stat on the menu bar, then Basic Statistics in the sub-menu, and then Display Descriptive Statistics in the subsequent sub-menu. This opens up a window in which the data columns to be used can be set up.
This sequence of commands describing the menu path is often written as Stat -> Basic Statistics -> Display Descriptive Statistics
The columns available for use in the command are on the left-hand side of the dialog box. The variables to be used in the operation are then entered in the block on the right-hand side. This can be done by
The Help button gives help on the command by clicking on it.
Typing Commands in the Session Window
MINITAB has several hundred commands. The screen prompt MTB> in the Session Window indicates that a MINITAB command may be entered. If the command language is not enabled (i.e. there is not a MTB> prompt present in the session window) it can be activated by
After the initial word, most MINITAB commands require arguments, specified as follows:
MEAN C1 K1
is the command which calculates the mean of C1 and stores it in constant K1, and
DESC C1 C2 C3 or DESC C1-C3
is the command which produces a full set of descriptive statistics for the data in the three columns C1, C2 and C3.
Some MINITAB commands (optionally) require sub-commands, which are invoked
by terminating the command with a semi-colon. After pressing the Enter
key, the MINITAB prompt SUBC> indicates
that an appropriate sub-command is required, or a full stop if no further
sub-command is required.
MINITAB has substantial help facilities which can be invoked and displayed
on the screen using the Help menu. This operates as a Windows help
system. To access help on a specific item, use Search for Help on
the sub-menu. Each menu also has its own Help button giving information
on how to use it and on what it does. In many cases examples of output
are also available.
There are three types of files which are associated with MINITAB
Opening, Saving and Retrieving a Project
At critical points in a work programme, and in particular if it is necessary to leave the terminal, the entire current project (including graphs) can be saved for subsequent recall by using the File -> Save Project As menu option.
At a later stage, the project can be retrieved using the File -> Open Project menu option.
Saving in this way saves the data in a special form which also retains the column names and any constants you have formed, together with the contents of the session window and any graphs you have currently opened. However in this form it can only be read by MINITAB.
You can also save the worksheet using the File -> Save Current Worksheet As (on the first occasion) and File -> Save Current Worksheet (on subsequent occasions). You can also save the worksheet in a form that can be used in earlier versions of MINITAB. (This latter option is not available for complete projects). There are several data files for use in the practicals already saved in this form. They are retrieved using the File -> Open Worksheet menu option.
Data can be entered directly into the spreadsheet simply by selecting the positions, using the mouse or the ¬ , , ® , or ¯ keys in the columns, and typing in the appropriate data values.
Names can be applied to columns by typing the required name into the cell at the top of the column.
Data can also be entered from a file using the File -> Other Files -> Import Special Text menu option. This will display the following dialog box:
Once you have entered the data columns into which the data will be stored (C1, C2, C3 etc.), click on OK to give the file selection menu.
Here, you can select the drive, directory and filename of the file containing
the data.
Worksheet data can be edited by selecting the cell in the data worksheet
and typing in the new values. Once the editing is complete, a different
cell must be selected to confirm completion.
Performing Calculations on Worksheet Data
Many commands perform calculations on the worksheet data. One very frequently used command is:
LET E = Expression
where the expression may refer to several columns and constants related by the arithmetic symbols +, -, * and /. For example,
LET C4 = 1 + C1 + K1*SQRT(C2)
sets the values into cells of the column C4
equal to the one plus the value in corresponding cell in C1
plus the value of the constant in K1
times the square root of the value in corresponding cell in C2.
Saving the Results of a MINITAB Session
Often the results of a series of MINITAB calculations are sufficiently important, lengthy and/or complex to warrant a permanent record which can be studied away from the terminal.
This can be achieved by one of several means.
If you wish to retain the contents for further use, you can
A MINITAB programme of work is terminated either by typing
STOP
in the Session Window, or by clicking on Exit in the Filemenu.
Placing MINITAB Output into Word
Click on the Start icon at the bottom left hand corner of the
screen, then click on Programs and select Microsoft Word
from the list of software by clicking on it.
From the set of icons at the bottom of the screen select your MINITAB session.
If your graphs have disappeared, minimise the Data window by clicking on the button with a line on it at the top right of the session window.
Select a graph you want to transfer by clicking the right mouse button on the graph and choose Copy Graph,
or highlight the text you want to transfer, then click the right mouse button and choose Copy.
Select your Word session from the set of icons at the bottom of the screen.
When in Word use menus Edit -> Paste to insert the text. The font selected will ensure correct spacing of tables but will probably be different from the font of the rest of your text.
To ensure that the graph stays where you put it, it is better to use
the Edit -> Paste Special menu and select Picture from the
list and also click on the small box next to Float Over Text so
that the tick is removed.
To print the document, get back into Word then use the menus File -> Print and click OK.
You need to specify the printer (PS27 or PS28 in the Bragg cluster). To check the print queue select the Print queue viewer icon.
Note that printing is not free, each page costs 5 credits. New users
have 60 credits; when these are used you will have to pay for extra credits.