Nick Fogal SPELL CORRECTION TECHNIQUES Overview Introduction Common

Nick Fogal SPELL CORRECTION TECHNIQUES

Overview � Introduction � Common Errors � Scenario � Methods � Applications � Future

I have a spelling checker It came with my PC It highlights for my review Mistakes I cannot sea. I ran this poem thru it I'm sure your pleased to no Its letter perfect in it's weigh My checker told me sew.

Introduction � Research began in 1957 for cursive writing and was used to find invalid entries in a database. � Spell checking software was first developed for main frame computers in the 1970 s. � Ralph Groin developed the SPELL program in assembly language

Errors � Missing character � Extra character � Wrong letters (“i” in place of “e”) � Transposition � Vulgar words (i. Phone) � Custom dictionary

Scenario � You own a local newspaper company and staff members are reviewing articles over and over again to make sure there are no spelling or grammar errors. This process is performed each day by different staff members and it is very time consuming. However, it is essential that you perform these processes. In the end, there is no way to guarantee that all errors have been fixed. However, you need a more efficient and reliable method.

Methods � Word List (Dictionary) �Word Frequency �Character Distance � Letter by Letter � Word splitting (Foreign languages) � Context Sensitive �Based on surrounding words (Microsoft Office)

Word Frequency � Take for example the misspelled word “whith”. The best correction would be to recommend the word “with”. Even though “whit” could have used it depends on how frequent words are used.

Character Distance The scores for the correction of "whith" are ("whit" 1. 41), ("with" 2. 24), ("which" 2. 83), and ("white" 3. 16). In contrast to the method using word frequencies, "whit" is the best correction

Context Sensitive � Andrew Golding and Dan Roth's "Winnow-based spelling correction algorithm", published in 1999, which is able to recognize about 96% of contextsensitive spelling errors, in addition to ordinary non-word spelling errors

Future � Available to understand sentence structure and context more effectively � Sentence comparison � Integrating multiple methods of recognition and correction

Questions?

References � � � http: //www. compassrose. com/publishing/aboutspell-checker. html http: //www. lrecconf. org/proceedings/lrec 2000/pdf/221. pdf http: //www. stanford. edu/~learnest/spelling. pdf http: //simson. net/ref/2006/csci_e-180/ref/spellingp 676 -peterson. pdf http: //grammar. about. com/od/spelling/a/spellcheck. htm http: //en. wikipedia. org/wiki/Spell_checker