The tutorial is a brief look at what Statistica for Windows is capable of doing. Examples will come from Statistical Methods for Psychology by David C. Howell. It is not our intention to teach you about statistics in this tutorial. For such information, you should rely on your classes in statistics and/or a good textbook. If you're a novice this tutorial should give you a feel for the programme and how to navigate through the many options. Beyond that, the Statistica Help Files represent all of the documentation relevant to using the programme.
The Basics
Interacting with Statistica is essentially like working with any
other programme designed for Windows. However, there are some
differences that will be discussed as we progress. Virtually
any statistic that you wish to perform can be accomplished in
combination with pointing and clicking on the menus and various
interactive dialog boxes. You may have noted that the examples
in the Howell textbook are performed/analyzed via code/programming
languages. That is, Statistica, like many other packages, can
be accessed by programming short scripts, instead of pointing
and clicking. We will not cover any programming in this tutorial.
However, this should not stop you from exploring this avenue via
the online documentation and examples.
Presumeably, Statistica is already installed on your computer. If you don't have a shortcut on your desktop go to the [Start=>Programs] menu and start the package by clicking on the Statistica icon. If you don't know what I'm talking about, ask some one at the local Computer HelpDesk.
Before proceeding any further I should say a few words about a very simple convention that will be used throughout this tutorial. In this point and click environment one must often navigate through many layers of menu items before encountering the required option. In the above paragraph the prescribed task was to locate the Statistica icon in the [Start] structure. To get at that icon, one must first click on [Start], then move the pointer to the [Programs] options, before locating the Statistica icon. This sequence of events can be conveyed by typing [Start=> Programs]. That is, one must move from the outer layer of the menu structure to some inner layer in sequence...
Now, back to the tutorial.
Once you have double clicked on the Statistica icon a new window will appear on the screen. This window will provide you with menu with several choices for analyses, like the following,
Using the scrollbar, you will note that your choices cover the full range of statistical procedures that you are likely to encounter. By double clicking on one of the options a new window will appear with a spreadsheet like interface. For now, double click on the Basic Statistics/Tables option to produce the following window,
[Note: I'm not fond of having a fullscreen display. The initial display of the above window occupied the fullscreen. To reduce the size of the window, click on the middle button on the upper right corner of the display. That is, the button with the overlapping boxes. I imagine there is preference setting that would automatically launch Statistica as a windowed display....]
The above window represents the interface to the Descriptive Statistics module. I suspect that this modular approach may be rooted in using less resources for a given set of analyses. That is, by just loading the resources for the required statistics, the load on the system is reduced. Or, I could be mistaken -- doesn't matter. Once the programme has been started one can open another module to conduct other analyses. For example, by clicking on [Analysis=>Other Statistics] you will once again be presented with the original choice menu. This time around, double click on the [ANOVA/MANOVA] menu item, or click on the End & Switch] button. The first approach will result in a new window, in addition to the Basic Statistics window, on the screen. So, one can have many instances of Statistica opened at the same time. The latter approach will close the Basic Statistic window, then open the ANOVA/MANOVA window. This should reduce the load on memory resources, howevever, the final choice is up to you.
As you can see, there are a number of menu options relating to statistics. There are also shortcut icons on the vertical and horizontal toolbar. These serve as quick access to often used options. Holding your mouse over one of these icons for a second or two will produce a short function description for that icon. The current display is that of an empty data sheet. Cleary, data can either be entered manually, or it can be read from an existing data file.
Browsing the File menu, displayed below, reveals nothing surprising - many of the options are familiar. Although, the details are specific to Statistica. For example, the [New] option leads to the opening of a new data sheet, with a unique name. Other interesting options include [Open Data] and [Import Data].
The [Open Data] option will launch a dialog box that can be used to open existing data files in a native Statistica format. Like other application packages (e.g., WordPerfect, Excel, ...) Statistica also has it's own format for saving data. In this case, the accepted extension for any file saved using the proprietary format is "sta". So, one can have a datafile saved as "data1.sta". Anyways, the format is not readable with a text editor (e.g., Notepad), it is a binary format. The benefits are that all formatting changes are maintained and the file can be read faster, hence the [Open Data] option. It is specifically meant for files saved in the SPSS format. The second option, [Import Data], as the name suggests is to read files that are not in the statistica format. These include ASCII, or text, datafiles and various spreadsheet formats. By clicking on [Import Data => Quick] one can specify the format of the data file to be read. That is, a new dialog box will appear, and one can scroll through the list of available file types - explore this dialog box.
Reading datafiles that are in a spreadsheet format requires very little effort. The process is seamless, however, reading ASCII files requires that the user know something about the format of the datafile. Otherwise, one is likely to get stuck in the process of reading. There are a number of acceptable formats - comma separated, space separated, semicolon separated, tab separated, and even a user defined format. For example, the following is comma separated file with 3 variables and 6 cases.
male,37,102 male,22,115 male,27,99 female,48,107 female,21,103 female,28,122
You should experiment with some artificial datafiles. It's possible to use a simple editor like NotePad - found on all Win95 machines - or a wordprocessor. If you use a wordprocessor, make sure you save the file in text format. Once you have a simple ASCII datafile click on [Import Data => Quick], and locate the file. After you have double clicked on the example file you'll be asked to specify the format, and that should do the trick.
Before we move onto actual data, click on [Analysis]. The menu that appears reveals a number of basic statistics that can be calculated. Recall, that we're currently using the [Basic Statistics] module. The components of the [Analysis] menu will change depending on the module being used.
