The definition of "astrostatistics" given in Wiktionary (accessed December 2012) is
astrostatistics: "The branch of astroinformatics that deals with statistical data".
I believe this is a poor choice of phrasing. Astrostatistics is quite independent of ... parallel to, not subsumed under ... astroinformatics. Wiktionary's definition of "informatics" is "a branch of information science, and of computer science, that focuses on the study of information processing,and particularly as respect to systems integration and human interactions with machine and data.". Whereas astrostatistics concerns the application of statistical methodology, often rooted in mathematical statistics, to astronomical data. And astrostatistics treats astronomical data, not "statistical data". Note related well-phrased in other Wiktionary definitions:
biostatistics: "The application of statistics to the study and analysis of biological and medical data"
geostatistics: "The application of statistics to geological observations"
chemometrics: "The use of mathematical statistics in the design of experiments, and the evaluation of the resulting data."
So I propose the definition should be changed to
astrostatistics: The application of statistics to the study and analysis of astronomical data.
Chair, Working Group in Astrostatistics and Astroinformatics, International Astronomical Union Prof. of Astronomy & Astrophysics Assoc. Dir. Center for Astrostatistics Pennsylvania State University