Using SPSS on VET
SPSS is the acronym of Statistical Package for Social Science. It is a very popular program for doing data analysis and manipulation. SPSS is also a very versitile program which can be run in interactive and batch mode formats. Furthermore, in the interactive format, SPSS can be used as a syntax based program or as a window based menu driven program. This page will present how both can be employed on the VET server. It is necessary to emphasize that the batch mode format is predicated on a base knowledge of SPSS programming syntax. The beginning SPSS user should spend some time to familarize themselves with the structure of SPSS command files. Links are provided below which go into the detail about this syntax as well as providing introduction to the Windows environment. SPSS on VET allows the statistical user to freely employ the program in whatever manner they find most comfortable.
Batch Mode
For batch execution, the user must first create an SPSS command file containing SPSS commands. It is necessary to learn both the syntax and different elements required to run a SPSS command file and the procedures to produce the desired analysis. For the novice SPSS user, an introduction and development of SPSS language can be acquired through the Getting Started with SPSS under the Unix Environment page from the University of IndianaStat/Math Center. This page provides example programs as well as explaining the necessary elements of each program, particularly defining and reading in data, naming variables, and analysis. Batch mode SPSS uses the program to produce both a log file and an output file. On the VET system a number of editors are available to create command file programs, Pico, aXe, Gnuemacs--these are detailed on the previous page under VET applications. Once a command file is created and saved, the program can be run in SPSS by simply typing spss -m -t and then the name of the program at the VET prompt. Using an example program entitled statistics, batch mode SPSS would look like:
Notice that statistics.lst is the output file and statistics is the input file. The & will enable you to run the job as a background process and free your terminal for other computing activities while the job runs in the background. If the & is not included, your terminal will not be free for other computing activities until the job is completed. Once the job is completed the output file will be stored in the default directory.
SPSS would then run the program and produce two other files, statistics.log and statistics.lst. Here statistics.log reflects the log of the program statistics detailing how SPSS reads the program and identifying any errors in the program. Statistics.lst reflects the output of the program statistics. Batch mode SPSS is easily run via through file listing type programs. By typing spss after the desired file, the SPSS program will be envoked and the command file run.
Interactive
Interactive SPSS is a graphically based version of the program and runs much like any Windows based version of SPSS. Interactive SPSS can be invoked by simply typing:
In order to run this graphical type of SPSS, it is necessary to have an X Window computer or an X Window simulator program. For IBMs and IBM compatable, X32Win is recommended by Information Technology. For Macs, Mac X is recommended. These programs will allow the computer to employ the graphical elements of SPSS.
Once invoked, the Interactive version of SPSS produces up to six windows: (1) a data editor window displaying the contents of a data file; (2) an output Navigator window displaying the output produced by varying procedures; (3) a pivot table editor which permits editting of tables produced by SPSS; (4) a chart editor window which permits editting of charts produced by SPSS; (5) a text ouput editor which can be used to edit text not included in charts or tables; and (6) a syntax editor. Given these windows, SPSS can be run in two methods. The first is a syntax based method much like the batch mode described above. Simply, once the program is open, the user can use the syntax editor in the same manner as they would be using any of the editors on VET and submit command files. The output will be produced in any of the output windows or editors as designated by the command program rather than a separate file. Simply, the syntax editor and the batch mode are very similar in that they rely on command files using SPSS language.
The second method is a menu driven windows based approach. This version of SPSS is often preferred by users as it does not require an indepth knowledge of SPSS syntax. Instead the user can run analysis through a series of menu based operations which can be engaged by pulling down the desired procedures. A fuller understanding of the windows approach can be gained by examining the Getting Started with SPSS for Windows page from the Indiana University Stat/Math Center or the Getting Started with SPSS for Windows page from Leeds University. Both provided detailed instruction as well as graphically presenting the menus and different screens.
SPSS Links
The following links provide a wide breadth of information about using SPSS, an introduction to SPSS programming, sample command files for macros and programs, applications including SAS graphing techniques, technical notes concerning changes in the SAS program and solutions to bugs, and SAS user groups. A brief explanation is offered with each link.
|
|
|
|
|
|
|
|
|
|