Statgraphics Introduction


Note: These instructions are aimed at getting you started with using Statgraphics at GVSU, they are not a full introduction to Statgraphics. We will be introducing additional capabilities as needed throughout the semester.


The R Drive


Often we will use Statgraphics on data sets from the textbook or ones that have been prepared ahead of time. These datasets will be stored on the GVSU lab network under the R drive. The R drive needs to be “activated” before you start Statgraphics in order to open files from it from within Statgraphics. If you start Statgraphics first, the R drive won’t show up and the files will not be visible.


To access the R:\ drive in Windows (XP), you must double-click on the ‘R: Data’ File Folder within the ‘Statistics’ folder before opening Statgraphics. To do this, follow these steps:


  1. Double-click the Departmental Applications folder.

  2. Double-click on the Statistics subdirectory folder.

  3. Double-click on the R: Data file folder.

  4. Notice the Zeitler folder. I will put datasets here under the 314 folder.

  5. Close the R drive; we will access it from Statgraphics instead.


Starting Statgraphics:

In the Statistics folder, double-click on the Statgraphics icon. This will bring up a dialog box asking where the data is coming from.

Nothing can be done without data. One can open an existing Statgraphics data set (a data set with a .sf3 extension), an existing Excel spreadsheet (.xls extension), or type in a new data set. The textbook data files are often stored as Excel files and will need to be imported into Statgraphics.


Opening Datasets from the R Drive

  1. Click OK when the initial Statgraphics dialog screen (StatWizard) opens.

  2. Select the 'in a Spreadsheet file' option and click OK.

  3. Change the Look in: box to the drive you want (something like Labdata ...)

  4. Open the Zeitler folder, then the 314 folder.

  5. If we are working on a special section, open the appropriate subfolder.

  6. Double-click the name of the data set you wish to open.

  7. Be sure 'Variable names from first row' is selected and click OK.


You should now have your data in a Statgraphics data sheet. You can save it to your own network drive at this point for later loading and work.



Data Editor

The Statgraphics data editor works similar to Excel except that the data is constrained to be columns of numbers or strings with a 'variable' label at the top. You should be able to use much of the data editing you're already familiar with here.

Double clicking on the label at the top of the column opens a dialog box which allows you to modify the properties of the variable. These properties include name, comment, column width and data type. We will primarily be using numeric and character in this last one.


Descriptive Statistics and Graphics

Descriptive information can be generated using the 'Describe' menu. Note that there are different sub menus for Numeric and Categorical data. Select the Numeric and One-variable option from this menu. This will bring up an analysis window with default statistics and graphics panes for a single variable.


Analysis window

The analysis window allows you to select statistics (tabular) and graphics panes using the buttons along the top of the window. The choices are dependent on the analysis procedure chosen. For One-variable analysis, we will see the following (the asterisks denote the default selections):


Tabular

Graphics

Analysis Summary*

Scatterplot*

Summary Statistics*

Box-and-Whisker Plot*

Percentiles

Frequency Histogram

Frequency Tabulation

Quantile Plot

Stem-and-Leaf Display

Normal Probability Plot

Confidence Intervals

Density Trace

Hypothesis Tests

Symmetry Plot


Right clicking in any of the analysis panes brings up a menu which allows you to modify options for the pane, the entire analysis window as well as printing or saving the analysis to the statreporter.


Generating Reports (statreporter)

The statreporter is a simple word processor built into Statgraphics. You can save your analysis to the statreporter using the right click method indicated above and then either edit it directly in Statgraphics by opening it in the statreporter window (it's usually minimized at the bottom of the Statgraphics window), saving the statreporter contents from the 'File:Save' menu or opening the statreporter and right clicking in the window to get a 'save' option.