Roger Mitton's Home Page

(photo circa 1997)


I was brought up in Morecambe, Lancashire. I studied classics at The Royal Grammar School, Lancaster and then Psychology and Philosophy at Merton College, Oxford, where I graduated in 1968. After a year at Stanford University, California, studying philosophy, I returned to London to help write the story of a community development project in Notting Hill, which I had got to know during a gap year as a Community Service Volunteer. I then did various pieces of social research and spent some months teaching English in Paris before going to Africa where I spent a term as an English teacher in Botswana and then three years as deputy director of the Lesotho Distance Teaching Centre. On returning to London in 1977 I was in charge of a European study of income support for the unemployed. It was while supervising the analysis of the data from this study that I became interested in computers and I took the Diploma in Computer Science at Birkbeck. I combined part-time work in computing with part-time study for a few years before joining this department, first as a research assistant and then, in 1986, as a lecturer. In 1989 the Diploma was superseded by the MSc Computing Science, of which I became course director and remained so until 2005. I retired from Birkbeck in 2012 but retain some connection as a visiting research fellow.


The main topic of my research has been spellchecking, more specifically the development of a spellchecker that can make good guesses about the words that the writer intended, even when the writer's spelling is poor; you can see a demo of its performance on isolated misspellings at did-you-mean.html. The products of my work include a computer-usable dictionary, a collection of spelling errors culled from many sources, a prototype spellchecker, a PhD thesis, a number of papers and a book, no longer in print but available from Birkbeck ePrints. I gave copies of the first two items - the dictionary and the error collection - to the Oxford Text Archive.

Two of my research students gained their PhDs in 2007, the first (click here) for work on the detection and correction of "real-word" errors (such as "there" for "their"), and the second (click here) on the generation of cryptic crossword clues. A third research student was working on the use of semantics to improve the order of a spellchecker's suggestions but had to give it up because of the demands of his full-time job.

If you are interested in spellchecking, you might like to read a short (now rather old) article Spellchecking by computer, or my book English Spelling and the Computer, or a more recent article Ordering the suggestions of a spellchecker without using context or, shorter and more readable, Fifty years of spellchecking.

There is also a simple demo of the suggestions-making part of my spellchecker at did-you-mean.

If you are doing research into spellchecking yourself, you might want to download a corpus of spelling errors.


My principal contribution to the department's teaching was a C++ programming module, which was taken mainly by students on the MSc/PGDip Computer Science. (See C++ notes.)

Published books

All these books are now out of print, but English Spelling and the Computer, and Practical Research in Distance Teaching, are available from Birkbeck ePrints.

Contact information

School of Computer Science and Information Systems
Birkbeck College
Malet Street
London WC1E 7HX

Telephone: +44 020 7631 6715