PSPP For Linux

PSPP is a tool for statistical analysis of sampled data. The project interprets commands in the SPSS language and produces tabular output in ASCII, HTML, or PostScript format.

The long term goals for PSPP are ambitious. We wish to provide the following support to users:

� All of the SPSS transformation language. PSPP already supports a large subset of it.

� All the statistical procedures that someone is willing to implement, whether they exist in SPSS or not. Currently, statistical support is limited, but growing.

� Compatibility with SPSS syntax, including compatibility with known bugs and warts, where it makes sense. We also provide an "enhanced" mode in certain cases where PSPP can output better results that may surprise SPSS users.

� Friendly textual and graphical interfaces. PSPP does not do a good job of this yet.

� Attractive output, including graphs, in a variety of human and machine-readable formats. PSPP currently produces output in ASCII, PostScript, and HTML formats. We will enhance PSPP's output formatting in the future.

� Good documentation. Currently the PSPP manual describes its language completely, but we would like to add information on how to select statistical procedures and interpret their results.

� Efficient support for very large data sets. For procedures where it is practical, we wish to efficiently support data sets many times larger than physical memory. The framework  for this feature is already in place, but it has not been tuned or extensively tested.

Over the long term, we also wish to provide support to developers who wish to extend PSPP with new statistical procedures, by supplying the following:

� Easy-to-use support for parsing language syntax. Currently, parsing is done by writing "recursive descent" code by hand, with some support for automated parsing of the most common constructs. We wish to improve the situation by supplying a more complete and flexible parser generator.

� Easy-to-use support for producing attractive output. Currently, output is done by writing code to explicitly fill in table cells with data. We should be able to supply a more convenient interface that also allows for providing machine-readable output.

� Eventually, a plug-in interface for procedures. Over the short term, the interface between the PSPP core and statistical procedures is evolving quickly enough that a plug-in model does not make sense. Over the long term, it may make sense to introduce plug-ins.