Difference Between Experimental Research and Observational Research
Experimental science involves discovering new knowledge by doing tests to see if a hypothesis is true. In an experiment, scientists carry out a series of steps, almost like a recipe. Scientists design and conduct experiments very carefully. They make sure that observations and measurements are as accurate as possible.
Many medical experiments are called clinical trials. For example, scientists might run a clinical trial to decide whether a new drug is better than an old drug. They might compare the results of each medicine on separate groups of patients in a clinic or hospital. In a clinical trial, both groups must be as similar as possible. They must be of the same age and health, for instance. If one group were older or sicker, they might respond to a drug differently. That difference could lead to false results.
To avoid false results, experimental scientists reduce the chances for errors in several ways. They may repeat an experiment several times. Scientists also encourage other researchers to repeat the experiment. To be meaningful, or valid, an experiment must be repeatable. Any scientist who does the experiment in the same way should get the same results. Scientists use statistics to decide whether findings are valid.
Scientists also make discoveries with theoretical and observational research. Theoretical research involves thinking about a problem. Einstein developed the theory of relativity in this way. He worked it out in his mind, without doing experiments. Modern theoretical scientists usually add to their brainpower by using computers. Computers can model, or portray, a problem and show how it changes under different conditions.
Observational research is probably the oldest kind of science. It involves observing events in the natural world and drawing conclusions. This approach helped Darwin develop his theory of natural selection. This theory describes how species evolve. Darwin formed it after observing similarities among plants and animals in different parts of the world.
Many modern scientists still work this way. They collect and analyze data. Astronomers, for instance, discover the nature of planets, stars, and other celestial objects by observing light and other forms of radiation that the objects emit. Geologists gather data about the composition of ancient rocks. Many new discoveries in genetics come from observations about the location, structure, and function of genes.
Research can also be basic or applied. Basic research tries to uncover new knowledge that has no immediate practical use. Applied research seeks knowledge that can be used to create new products or in other practical ways.