Department of Statistics
Penn State University

Introduction to Minitab 12 for Windows

IBM/DOS Public Labs

Minitab for Windows is available for student use at all public computer labs at the University Park campus. Students need an access account user ID and password to use any computer in the labs. In this document all commands will be carried out with pull-down menus and the mouse in an exclusively Windows environment.

Starting Minitab

Once you have logged onto a CAC computer, click on the Start button in the bottom left-hand corner of the screen. A menu will appear which includes Statistics and Spreadsheets. Move the mouse to this selection and click on Minitab 12 from the sub-menu that appears. This will activate the software.
 

Figure 1: Minitab for Windows

Figure 1 illustrates how Minitab looks when you first begin the program. Initially, the Session window and the Data window are open. The title bar of the active window is blue, and the other window has a gray title bar. The outer-most or background window contains pull-down menus for statistical analyses, and short cut buttons. If you position the mouse over any of the short cut buttons without clicking, a description of the button will appear.

Worksheet window: The Worksheet window is where you enter the data to be analyzed.  The data for each variable is stored in a different column. At the top of each column is a blank cell for specifying the name of the variable. A variable may be referred to by its name or column location (c1 for column 1, c2 for column 2, etc.)  (If the Data window is not visible on the screen, select Data from the Window pull-down menu. This will activate the Data window.)

Session window: In general, the Session window is where Minitab will print the results of an analysis.  Minitab also prints the commands that generated the results in the session window, too, but don't worry about the commands.  You will use pull-down menus to tell Minitab what to do.  (If the Session window is not opened, select Session from the Window menu to open the window.)

You may edit the output in the Session window, delete lines or add lines, much as you would in a word processor. This feature can be very useful for the preparation of assignments.

History window: This window lists all the commands that have been entered during the current Minitab Session, but without the output generated by those commands. The history window may be accessed by selecting History from the Window menu at the top of the screen.

Info window: This window lists information about the active worksheet (i.e. the data currently showing in the Data window). This window is also accessed from the Window menu.

Entering Data

To enter data, you have to activate a Worksheet window by clicking once on the Worksheet window's title bar.  The Worksheet window is active when the title bar turns blue.  Use your mouse, the keypad, and the carriage return to enter the following data into columns C1 and C2.  The data represent the average temperatures for Atlanta and New York for the twelve months of the year.
 

C1 C2 C3
Month Atlanta New York
1 1 42 32
2 2 45 33
3 3 51 41
4 4 61 52
5 5 69 62
6 6 76 72
7 7 78 77
8 8 78 75
9 9 72 68
10 10 62 58
11 11 51 47
12 12 44 35

The space above the first row is reserved for variable names. If you haven't already done so, name the first column "Month", the second column "Atlanta", and the third column "New York."  If you choose not to specify variable names, you can refer to the variables during analysis by their column names, namely C1, C2, etc.

Should you mistakenly enter an incorrect value, editing data is simple. Simply move to the data cell, by clicking once on the desired cell, and type in the corrected value. The pull-down Edit menu offers some other editing functions which may be of interest.

Analyzing Data

Once you have entered the data, you can analyze the data graphically or numerically.  In general, all of the graphical analyses available in Minitab are under the Graph menu, and all of the numerical analyses available in Minitab are under the Stat menu.  Also, in general, the results of numerical analyses appear in the Session window, while graphical results appear in a separate graph window.

As an example of a numerical analysis, calculate the basic descriptive statistics (n, mean, minimum, range, etc.) for Atlanta's average monthly temperatures:

  1. Select Stat.
  2. Select Basic Statistics.
  3. Select Display Descriptive Statistics...
  4. The Display Descriptive Statistics Pop-Up Window will appear.  In the left box, click once on the variable you want analyzed ("Atlanta").  Click once on the Select button.  The column name (or variable name) will appear in the box labeled Variables.
  5. Select OK.  The output will appear in the Session window.
The following output should appear:
Descriptive Statistics

Variable             N       Mean     Median     TrMean      StDev    SE Mean
Atlanta             12      60.75      61.50      60.90      13.80       3.98

Variable       Minimum    Maximum         Q1         Q3
Atlanta          42.00      78.00      46.50      75.00

Now, as an example of a graphical analysis, create a boxplot of New York's average monthly temperatures:

  1. Select Graph.
  2. Select Boxplot....
  3. The Boxplot Pop-Up Window will appear.  In the left box, click once on the variable you want analyzed ("NewYork").  Click once on the Select button.  The column name (or variable name) will appear under the Y in the box labeled Graph Variables.
  4. Select OK.  A new graph window, which contains the boxplot, will appear.

Saving Your Work

Once you've entered data and performed your analyses, you may want to save your work for later use.  You can either save just your data ("the worksheet") or you can save your data and your output ("your project").

To save just your data:

  1. Select File.
  2. Select Save Current Worksheet As...
  3. The Save Worksheet As Pop-Up window will appear.  If it does not say "31/2 Floppy (A:)"  in the Save in: box, click on the yellow folder button with an arrow to the right of the Save in: box to find the A: drive.
  4. Type the desired file name in the File name: box.
  5. Select Save.  Minitab will save the file with your desired name and an *.mtw extension.
To save your data and your work:
  1. Select File.
  2. Select Save Project As...
  3. The Save Project As Pop-Up window will appear.  If it does not say "31/2 Floppy (A:)"  in the Save in: box, click on the yellow folder button with an arrow to the right of the Save in: box to find the A: drive.
  4. Type the desired project name in the File name: box.

  5. Select Save.  Minitab will save the project with your desired name and an *.mpj extension.
Opening Your Previous Work

Opening a worksheet or project works similarly as saving a worksheet or project.

To open a worksheet (*.mtw):

  1. Select File.
  2. Select Open Worksheet...
  3. The Open Worksheet Pop-Up window will appear.  Using the the yellow folder button with an arrow to the right of the Look in: box, find the drive that contains the desired worksheet.
  4. Select the desired file so its name appears in the File name: box.
  5. Select Open.  Minitab will open the desired worksheet.
To open a project:
  1. Select File.
  2. Select Open Project...
  3. The Open Project Pop-Up window will appear.  Using the the yellow folder button with an arrow to the right of the Look in: box, find the drive that contains the desired project.
  4. Select the desired file so its name appears in the File name: box.
  5. elect Open.  Minitab will open the desired project.
Using Help

Minitab for Windows has a comprehensive help database with detailed information on all the commands and topics. There are two ways of accessing help. When you want to learn more about Minitab for Windows or a specific topic, go to the Help menu at the top of the screen and select Contents. Clicking on the ? button on the tool bar will also call up the help window.

If you are using a specific command and are confused by any of the options listed in the dialog box for that command, simply click the Help button within the dialog box. This will provide you with detailed explanations of the available options for the command you are using. You may also print information from the Help database. Please print only those pages which are of use to you since the printers are shared by everyone.

Printing

Printing graphs, data or session windows can be done at any stage of your Minitab session.  To print any window:

  1. If it is not already, activate the window you wish to print by clicking anywhere on the window.  (The window is activated when the bar is blue; it is not activated when the bar is gray.)
  2. Select File.
  3. Select Print Window.
  4. Select OK.
The contents of your window will print out at the default printer in the lab in which you are working.

Exiting Minitab

Before exiting Minitab, be sure that you have saved your worksheets and/or project.  Then to exit Minitab:

  1. Select File.
  2. Select Exit.
Also, see the Minitab Cheat Sheet for Descriptive Statistics.

Last Updated: September 3, 1998