I assume that you know the usual procedure is to 'score' each essay by a vector that gives the frequency of occurrence of commonly used (sometimes adding subject matter specific) words and phrases. This multivariate response is then fed in as a "training set" into your favorite supervised learning/classification procedure. R has many of these -- trees, logisic regression, boosting, Random Forests,svm's,LDA,SOM's (whoops -- that's an Unsupervised one), ... . Try RSiteSearch('Classification',restrict=('functions').
The devil is in the details as to what works best, I believe. With only 78 exemplars in 10 groups, unless there is a lot of separation (disparate styles that you could probably detect manually) it may be difficult. It also depends on how large each group is (balance is generally better). Cheers, Bert -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Werner Bier Sent: Sunday, June 12, 2005 12:30 PM To: r-help@stat.math.ethz.ch Subject: [R] Essay identification Hi R-help, I have a database of 10 students who have written an overall of 78 essays. The challenge? I would like to identify who wrote the 79th essay. Has anybody used R in this context? Even if not, would you suggest me which pattern recognition technique I might possibly apply? Thanks a lot and regards, Tom --------------------------------- [[alternative HTML version deleted]] ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html