Java software analyze "The Cuckoo’s Calling" and found author as J.K. Rowling

The software is JGAAP (Java Graphical Authorship Attribution Program). [1]

Reading the article makes it clear that it wan't an identification as much as a confirmation of Rowling as the author. The analysis was the result of suspicions triggered by an anonymous tip via Twitter.

The analysis used a corpus of only four authors' works. Rowling was the most likely of the four.

[1] http://evllabs.com/jgaap/w/index.php/Main_Page

The headline sounds like the guy was analyzing texts in general and came up with this match; a needle in the haystack thing.

The story is less interesting. An anonymous Twitter tip said, "Hey I think that J.K. Rowling wrote The Cuckoo's Calling." The result of running it through the software was: yeah, she probably did.