During prenatal development, the arm develops before the fingers. This most illustrates the ____ principle

In the world of human-computer interaction, the keyboard or mouse that is used to alter the activity of a computer would be referred to as controls

Indicate whether this statement is true or false.

Placebos are used in research to control for

a. nontreatment effects. b. the subjects' expectations about treatment. c. secondary drug effects. d. random fluctuations in the independent variable.