The scientific Method

Biology

The study of living things.

Hypothesis

A proposed explanation for an observation.

An experiment

A test for a hypothesis

Variable

A factor that may change in an experiment.

A control

Used to act as a comparison to the test.

Large sample size

More reliable results

Random selection

Reduces bias

A replicate

A repeat of an experiment

Double-blind testing

When neither the tester nor the subject know who gets the placebo.

Fair testing

1. Large sample size

2. Random selection

3. Others must be able to replicate experiment

4. Double-blind testing

Limitations of the value of the scientific method

1. Extent of our knowledge

2. Basis of investigation

3. Human error

4. Ability to interpret results

5. Bias

Good experimental design features

1. A control

2. Only one variabke

3. Safe procedure

4. Large sample size

5. Repeatable/replicates