Joseph Rézeau
Original author
Selecting a mode other than None will display a button to enable the student to get the next letter or word (including the very first letter or word).
In Adaptive mode the button displayed will say "Buy next letter" or "Buy next word" according to the mode selected by the teacher. For setting the "cost" of buying a letter or word, see the Penalty for incorrect tries and Buying a letter or word settings further down the Edit form.