The word dichotomous is derived from the Greek words meaning “two parts.” Each step in the key provides two contrasting choices about a characteristic. Each alternative choice then leads to another pair of clues and then another, until the items are identified.

How is a dichotomous key developed?

“Dichotomous” means “divided into two parts.” That is why dichotomous keys always give two choices in each step. In each step, the user is presented with two statements based on characteristics of the organism. If the user makes the correct choice every time, the name of the organism will be revealed at the end.

What was the dichotomous key based on?

“Dichotomous” means divided into two parts, hence the dichotomous keys always present two choices based on the key characteristics of the organism in each step. By correctly selecting the right choice at each stage, the user will be able to identify the name of the organism at the end.