SPSS Statistics is a software package used for interactive, or batched, statistical analysis. Long produced by SPSS Inc., it was acquired by IBM in 2009. Current versions have the brand name: IBM SPSS Statistics.
The software name originally stood for Statistical Package for the Social Sciences, reflecting the original market, then later changed to Statistical Product and Service Solutions.
OverviewSPSS is a widely used program for statistical analysis in social science. It is also used by market researchers, health researchers, survey companies, government, education researchers, marketing organizations, data miners, and others. The original SPSS manual has been described as one of "sociology's most influential books" for allowing ordinary researchers to do their own statistical analysis. In addition to statistical analysis, data management and data documentation are features of the base software.
Statistics included in the base software:
- Descriptive statistics: Cross tabulation, Frequencies, Descriptives, Explore, Descriptive Ratio Statistics
- Bivariate statistics: Means, t-test, ANOVA, Correlation, Nonparametric tests, Bayesian
- Prediction for numerical outcomes: Linear regression
- Prediction for identifying groups: Factor analysis, cluster analysis, Discriminant
- Geo spatial analysis, simulation
- R extension, Python
Additionally a "macro" language can be used to write command language subroutines. A Python programmability extension can access the information in the data dictionary and data and dynamically build command syntax programs. The Python programmability extension, introduced in SPSS 14, replaced the less functional SAX Basic "scripts" for most purposes, although SaxBasic remains available. In addition, the Python extension allows SPSS to run any of the statistics in the free software package R. From version 14 onwards, SPSS can be driven externally by a Python or a VB.NET program using supplied "plug-ins".
SPSS Statistics places constraints on internal file structure, data types, data processing, and matching files, which together considerably simplify programming. SPSS datasets have a two-dimensional table structure, where the rows typically represent cases and the columns represent measurements. Only two data types are defined: numeric and text. All data processing occurs sequentially case-by-case through the file. Files can be matched one-to-one and one-to-many, but not many-to-many. In addition to that cases-by-variables structure and processing, there is a separate Matrix session where one can process data as matrices using matrix and linear algebra operations.
The graphical user interface has two views which can be toggled by clicking on one of the two tabs in the bottom left of the SPSS Statistics window. The 'Data View' shows a spreadsheet view of the cases and variables. Unlike spreadsheets, the data cells can only contain numbers or text, and formulas cannot be stored in these cells. The 'Variable View' displays the metadata dictionary where each row represents a variable and shows the variable name, variable label, value label, print width, measurement type, and a variety of other characteristics. Cells in both views can be manually edited, defining the file structure and allowing data entry without using command syntax. This may be sufficient for small datasets. Larger datasets such as statistical surveys are more often created in data entry software, or entered during computer-assisted personal interviewing, by scanning and using optical character recognition and optical mark recognition software, or by direct capture from online questionnaires. These datasets are then read into SPSS.
SPSS Statistics can read and write data from ASCII text files, other statistics packages, spreadsheets and databases. SPSS Statistics can read and write to external relational database tables via ODBC and SQL.
Statistical output is to a proprietary file format for which, in addition to the in-package viewer, a stand-alone reader can be downloaded. The proprietary output can be exported to text or Microsoft Word, PDF, Excel, and other formats. Alternatively, output can be captured as data, as text, tab-delimited text, PDF, XLS, HTML, XML, SPSS dataset or a variety of graphic image formats.
Several variants of SPSS Statistics exist. are highly discounted versions sold only to students. SPSS Statistics Server is a version of SPSS Statistics with a client/server architecture. Add-on packages can enhance the base software with additional features. SPSS Statistics is available under either an annual or a monthly subscription license.
SPSS Statistics launched version 25 on Aug 08, 2017. SPSS v25 adds new and advanced statistics, such as random effects solution results, robust standard errors, and profile plots with error bars within the Advanced Statistics and Custom Tables add-on. V25 also includes new Bayesian Statistics capabilities, a method of statistical inference and publication ready charts, such as powerful new charting capabilities, including new default templates and the ability to share with Microsoft Office applications.
Versions and ownership historyThe software was released in its first version in 1968 as the Statistical Package for the Social Sciences after being developed by Norman H. Nie, Dale H. Bent, and C. Hadlai Hull. Those principals incorporated as SPSS Inc. in 1975. Early versions of SPSS Statistics were written in Fortran and designed for batch processing on mainframes, including for example IBM and ICL versions, originally using punched cards for data and program input. A processing run read a command file of SPSS commands and either a raw input file of fixed format data with a single record type, or a 'getfile' of data saved by a previous run. To save precious computer time an 'edit' run could be done to check command syntax without analysing the data. From version 10 in 1983, data files could contain multiple record types.
Prior to SPSS 16.0, different versions of SPSS were available for Windows, Mac OS X and Unix.
SPSS Statistics version 13.0 for Mac OS X was not compatible with Intel-based Macintosh computers, due to the Rosetta emulation software causing errors in calculations. SPSS Statistics 15.0 for Windows needed a downloadable hotfix to be installed in order to be compatible with Windows Vista.
From version 16.0, the same version runs under Windows, Mac, and Linux. The graphical user interface is written in Java. The Mac OS version is provided as a Universal binary, making it fully compatible with both PowerPC and Intel-based Mac hardware.
SPSS Inc announced on July 28, 2009 that it was being acquired by IBM for US$1.2 billion. Because of a dispute about ownership of the name "SPSS", between 2009 and 2010, the product was referred to as PASW. As of January 2010, it became "SPSS: An IBM Company". Complete transfer of business to IBM was done by October 1, 2010. By that date, SPSS: An IBM Company ceased to exist. IBM SPSS is now fully integrated into the IBM Corporation, and is one of the brands under IBM Software Group's Business Analytics Portfolio, together with IBM Algorithmics, IBM Cognos and IBM OpenPages.
Companion software in the "IBM SPSS" family are used for data mining and text analytics, and realtime credit scoring services.
SPSS Data Collection and SPSS Dimensions were sold in 2015 to UNICOM Systems, Inc., a division of UNICOM Global, and merged into the integrated software suite UNICOM Intelligence.
(Interactive Data Analysis)IDA was a software package that originated at what formerly was the National Opinion Research Center, at the University of Chicago. Initially offered on the HP-2000, somewhat later, under the ownership of SPSS, it was also available on DEC's DECSYSTEM-20.
- Conversational / Columnar SPSSSCSS was a software product intended for online use of IBM mainframes.
Although the "C" was for Conversational, it also represented a distinction regarding how the data was stored: it used a column-oriented rather than a row-oriented database.
This gave good interactive response time for the SPSS Conversational Statistical System, whose strong point, as with SPSS, was Cross-tabulation.