Experimental Design Concepts ILS

The factor that gets changed.

Example: amount of water given a plant to measure growth

The factor that is measured or observed

and changes based on the

independent variable

Example: the plant's height was dependent on the amount of water it was given

Group not exposed to the treatment,

used for comparison

Example: Group given no change in amount of water

Group exposed to or given the independent variable.

Example: Students who used the new study technique

Testable prediction

Example: increased sunlight will make plants grow taller

Repeating an experiment many times to be sure the results are reliable.

Example: testing a new drug on hundreds of different patients

Things that are kept the same for all experimental groups.

Example: Types of soil and the size of the pot were the same for all plants

Not numerical

Example: the color of the leaves

Numerical measures or counts.

Example: what is the exact temperature, or how tall is the plant

Tendency to favor a certain outcome, skewing the results.

Example: previous experiences or beliefs