Studies that involve the control and manipulation of variables

Studies that involve the observation of individuals or the measurement of certain outcomes. No attempt is made to affect the outcome (e.g., no treatment is given).

What do both experimental and observational studies have in common?

What studies are considered the "gold standard" of research methodology?

What studies are considered "less invasive"?

What studies are used when there is possible harm to the patients?

A relationship in which one variable can be said to be the cause of another.

The degree of relationship between two different variables.

What is the only type of study that can determine causal relationships?

What is the type of study that researchers try to use whenever possible?

What are the three types of studies that observational studies are used in?

A research study that compares a particular outcome in groups of individuals who are alike in many ways but differ by the variable the researcher is studying

What are the two types of cohort studies?

What are cohort studies AKA?

Outcomes have not yet occurred as study begins; not always feasible

Outcomes have already occurred as the study begins

A research study that involve multiple observations which may be useful to determine how variables affect each other at the same time and period. Ex. Questionnaire to determine how income is related to weight

A study in which another researcher can perform exactly the same experiment and generate results with the same statistical significance.

A study in which the results accurately describe the real world.

One group receives the treatment and another group does not.

The control group and treatment group are chosen at random.

This practice allows researchers to eliminate bias that participants or investigators have introduced by having knowledge of the treatment or control conditions in an experiment.

The participant does not know whether he or she has been allocated to a treatment or control group.

Neither the participant, the researcher, nor the response gatherer knows whether the participant has been allocated to a treatment or control group.

Neither the participant nor the researcher knows whether the participant has been allocated to a treatment or control group.

What must be eliminated to ensure valid results in an experiment?

A variable that was not accounted for in the experimental design, varies systematically with the dependent variable, and prevents a clear interpretation of the effect of the independent variable on the dependent variable.