Praxis 5236 Biology: Content Knowledge course

FREE CHAPTER

Controlled experiments

Why does controlled experiments matter on the Biology exam? It helps you interpret evidence instead of memorizing a label.

Key words

Controlled experiments

A controlled experiment changes one independent variable while measuring a dependent variable; other conditions remain comparable. — e.g. Two plant groups receive different light durations but identical soil, water, and species.

Evidence

Observations or measurements used to evaluate a claim about controlled experiments. — e.g. Two plant groups receive different light durations but identical soil, water, and species.

Mechanism

The causal process that explains how controlled experiments works. — e.g. A controlled experiment changes one independent variable while measuring a dependent variable; other conditions remain comparable.

Prediction

An expected result derived from a testable model of controlled experiments. — e.g. Identify light duration as the manipulated factor and plant growth as the outcome.

Misconception

An appealing but incorrect explanation about controlled experiments. — e.g. A larger sample does not remove the need to control other variables.

Remember this

• A controlled experiment changes one independent variable while measuring a dependent variable; other conditions remain comparable.
• Identify light duration as the manipulated factor and plant growth as the outcome.
• Avoid this mistake: A larger sample does not remove the need to control other variables.

CONTROLLED EXPERIMENTS: EVIDENCE → RULE → CHECK THE MISCONCEPTION.