The buttons appearing at the bottom of the element window are called the learning buttons. This buttons are visible only in Full Access and Learn-Only modes (i.e. not if Tools : Options : Data Access : Access Mode : Read-Only is checked):
Learn - start the three-stage learning process: (1) repeating outstanding items, (2) learning new items, and (3) repeating again items that caused difficulties in stages (1) and (2). This is equivalent to pressing Ctrl+L.
Reset - remove the currently displayed element from the learning process (if already memorized). Equivalent to pressing Ctrl+R.
Dismiss - ignore the displayed item or topic in the learning process. Dismissed items are never presented to the student while memorizing new items; however, they can be memorized with Commit. Equivalent to pressing Ctrl+I.
Review - memorize (or review, if memorized) all descendants of the currently displayed topic. Equivalent to choosing Review in Contents window.