Texas Instruments TI-89 Manual Book page 20

After all cards have been answered correctly, a screen confirms,
ending the study session.
To start the stack over, press „. To view results, press ....
For a stack with difficulty levels (and with turned off),
Ignore Levels
the StudyCards™ Viewer sets up the first run (Run #1) through
level 1 cards. When you correctly answer the required number of
level 1 cards in the run, the StudyCards Viewer sets up the first
run (Run #1) through level 2 cards.
TI-89/TI-92 Plus/Voyage™ 200 PLT StudyCards™ Viewer Page 20