Input to the ALEKS system is always in the form of proper mathematical expressions and constructions, never multiple choice. A critical reason for this is to prevent substantial inaccuracies which arise from students' guessing and trying out the different choices. Another purpose of this approach is to train students in the same skills that are necessary for conventional, paper-and-pencil communication of solutions and results. At the same time, the sophistication of the ALEKS input tools provides certain advantages. The presentation of results is always neat and clear. Manual dexterity plays a reduced role in drawing an accurate graph or geometrical construction. Immediate feedback is provided on the formal completeness of solutions.

The general term for the input tools used in ALEKS is the "Answer Editor." This encompasses a variety of actual modes for user input: an Answer Editor for mathematical expressions, an Answer Editor for the numberline, an Answer Editor for graphing in the Cartesian plane (with x and y coordinate axes), and an Answer Editor for histograms (in Statistics). A student beginning to use ALEKS is thoroughly trained in all features of the Answer Editor that are relevant to the subject being studied during the Tutorial (See Sec. 3.8).

In much of what follows, emphasis is on the "Answer Editor for mathematical expressions," as this is the section which involves the greatest degree of interplay between mouse, keyboard, and on-screen buttons and icons.