Non experimental research

Non experimental research
There are many research problems that can be conducted using experimental or quasi experimental designs. In non experimental research, the independent variable is non-manipulate or unethical to manipulate, however, gives answers for research questions. 

Types of non experimental research
Correlational or Expost facto research has been conducted to study the relationships among variables after variation in the independent variable has occurred. It is designed to assess causal relationship between variables. it is divided into two types; Prospective study and Retrospective study

• Prospective study

In prospective study, the researcher looks forward to assess the effect and study is started with an examination of presumed cause. For example, the researcher selects samples of chronic alcoholics and non alcoholics and continues assessment for a period of time and later assesses the effect.

• Retrospective study

In retrospective study, the researcher observed at the effect of present and looks on to past history of the samples to collect and compare antecedent factors that have caused it.
Another class of non experimental research is descriptive research. The purpose of descriptive research studies is to observe, describe and document aspects of a situation. The researcher uses percentages or proportions to present the results. In descriptive correlational study, the researcher describes relationships among variables, but not causal connection.
Disadvantages of non experimental research
The major disadvantage is its inability to reveal casual relationships conclusively. It may be having false interpretation because the researcher works with known groups.