Bayesian Classification Applied
To Spelling Correction

• The noisy channel approach was first suggested by Kernighan, Church and Gale (1990)
• Their program (called correct)
  • Takes words rejected by the Unix spell progam
  • Generates a list of potentially correct words
  • Ranks them according to the the above equation
  • Picks the one with the highest rank
• We will follow the correction of the word acress which proceeds in two steps, proposing candidates, and ranking candidates.