I. Introduction
Spelling errors occur in many kind of Indonesian texts regardless of their formality (whether they are formal texts or informal texts). Spelling errors are very common in human-generated texts and the cause of them can vary from accidental hand or mind slips to writer's lack of spelling knowledge. For reading purpose, spell detecting and correcting might be trivial for humans since humans can naturally detect patterns easily that make them able to read and understand texts even though the texts have spelling errors, while machines cannot do it without being instructed or trained to.