Statistics Ch4: Observations and Experiments

The response variable is the outcome that is measured in an experiment, which is affected by changes in the explanatory variable.

The explanatory variable is the factor that is manipulated or changed in an experiment to observe its effect on the response variable.

An observational study is a statistical study where the researcher observes subjects without manipulating any variables or conditions.

A controlled experiment is a scientific test where one variable is changed while all others are kept constant to determine its effect.

The control group serves as a baseline to compare the effects of the experimental treatment, helping to isolate the impact of the explanatory variable.

A sample survey collects data from a subset of a population to infer characteristics of the whole population, while an observational study involves observing subjects without intervention.

The independent variable is the one that is changed or controlled in an experiment to test its effects on the dependent variable.

Randomization helps eliminate bias by ensuring that each subject has an equal chance of being assigned to any group, leading to more reliable results.

A hypothesis is a testable statement predicting the relationship between the explanatory and response variables.

Replication involves repeating an experiment multiple times to ensure that results are consistent and reliable.