At first glance, it may appear that a treatment versus no-treatment experiment eliminates the independent variable. However, the researcher still creates treatment conditions by manipulating different values of the treatment variable; the no-treatment condition is simply a zero-value of the independent variable. Thus, the experiment compares one condition having a “full amount” of the treatment with a second condition having a “zero amount” of the treat- ment. The independent variable still exists, and its two levels now consist of treatment and no-treatment control.