A research design with some, but not all, of the characteristics of an experimental design. While comparison groups are available and maximum controls are used to minimize threats to validity, random selection is typically not possible or practical.
This procedure likewise attempts to establish a cause and effect relationship. It is very similar to experimental design except that other means are used to control extraneous sources of causality. See the Tool Kits on this web site for specific instructions.
A study that seems like an “experimental study” and is designed to be almost as powerful a test as if it were experimental, but the people studied are not put into their groups randomly and there is no “comparison or control group.
A design similar to an experimental design but using quasi-independent variables.
In evaluation, methods that do not involve randomly assigning members of the target population either to an intervention or to a comparison group.
A non-randomized experimental design that compares what happens to the target of a conservation activity to groups (places) who are not the target of a conservation activity. One example of a quasi-experimental design that is a pre-post quasi-experimental design in which a comparison is made for a group prior to initiating the activity and afterwards. A second example involves the construction of a control or comparison group (or site) with comparisons made between the “treatment†group (site) subject to the conservation activity and that which is not subject to it. The selection of the “treatment†and “control†groups is done through means other than randomization.
A research design that differs from an experimental design because participants are not randomly allocated to groups. An example might be testing two classes from the same age group or workers from two different offices. There is the assumption that both groups are equivalent but this is unlikely to be the case. This method is most common in social psychology research.