Hi Bob, This check box adds words to your vocabulary automatically. The problem with this function is that it adds every utterance that is not in the vocabulary. So, your vocabulary gets cluttered and could lead to the degradation of accuracy. You can use this function but you need to keep cleaning out your vocabulary using the vocabulary editor. Pranav -----Original Message----- From: j-say-bounce@xxxxxxxxxxxxx [mailto:j-say-bounce@xxxxxxxxxxxxx] On Behalf Of robert fenton Sent: Monday, July 13, 2009 6:36 PM To: j-say@xxxxxxxxxxxxx Subject: [j-say list] Adding words to vocabulary Hi everybody: Why is it recommended that the setting to automatically add words to the vocabulary is un-checked when using J-Say? Can this feature be activated by an experienced user without reducing performance? Thank you for your help. Bob Fenton