What are the difference between an experiment and an observation?
In an experiment investigators apply treatments to experimental
units (people,
animals, plots of land, etc.) and then proceed to observe the
effect of the
treatments on the experimental units.
n an observational study investigators observe subjects and
measure variables
of interest without assigning treatments to the subjects. The
treatment that each
subject receives is determined beyond the control of the
investigator.
For example, suppose we want to study the effect of smoking on
lung capacity in women.
Summary:
1.The main difference between observational study and
experiments is in the way the observation is done.
2.In an experiment, the researcher will undertake some
experiment and not just make observations. In observational study,
the researcher simply makes an observation and arrives at a
conclusion.
3.In observational study, no experiment is conducted. In this
type of study the researcher relies more on data collected.
4.In an experiment, the researcher observes things through
various studies.
5.There is human intervention in experiments whereas there is no
human intervention in observational study.
6.Hawthorne studies are a good example for experiments.
7.The study to determine the relation between smoking and lung
cancer is a typical example for observational study.