Observations Studies And Experiments, And Experimental Designs

Experiment

Researchers assign people to treatment groups to see if something causes a change.

Observational Study

Researchers observe and, collect data without assigning treatments.

Randomization

People are assigned randomly to treatment groups to avoid bias.

Replication

Use enough people or, cases, so results are more reliable (test sample of 500 people rather than 5)

Controlling

Applying the same conditions to all subjects within groups to isolate the one that gets the placebo.

Blocking

Splitting into groups with similar characteristics before study reduce bias in experiment

Blinding ,Double Blinding

Blinding the subject, or researcher/ blinding both (either don’t know the treatment assigned)

Independent Variable

A variable that you manipulate to see an effect or have a different value.

Explanatory Variable

The variable that may explain why something happens .