Answer to Question 1
When an observational research design is employed, no manipulation is made and data is merely gathered on the
subject or subjects of interest. A group who is at risk for some disorder or one that has a particular disorder may
be studied in order to gather information as to the factors that might influence the development of the disorder or
the progression of the disorder. Just as a control group is used in an experiment, a control group must be used
when conducting observational research. It is important, however, to recognize that no conclusions can be made
about cause and effect. Correlational dataobserving that two factors are relateddoes not permit such
conclusions to be made as other factors may be the true cause for the observed relationship. For example, if a
researcher observes a correlation between obesity and depression, it can't be concluded that depression causes
obesity or that obesity causes depression. While either may be true, it cannot be determined that from such data.
In addition to these obvious causal connections, there could be additional factors that are causing both problems.
Thus, while observational research designs provide information as to how things are related, no conclusions can
be made as to cause and effect.
Answer to Question 2
b
Approach used to determine the evolutionary relationships among many animal species using molecular
The U.S. Long-Term Ecological Research (LTER) network.
Rational design of neuraminidase inhibitors
Reservoir/Storage/Impoundment approach
Modern house door design
Research Methods