Grouping thorough research design principle can not be made today, because each expert group the type of research design in accordance with the conditions of scientists themselves.
Among the grouping of research design principle, we know are:
1. Design for research with control group;
2. Design for descriptive and analytical studies
3. Design for field studies
4. Design of the study with the dimension of time
5. Design for evaluative studies - nonevaluatif
6. Design by using knowledge of primary or secondary knowledge
The study design has a wide range of views from various perspectives, among others:
1. Design the study based on the problem formulation;
- Exploratory research;
- Hypothesis testing
2. Research design based on data collection methods:
- Observational studies
- Research Survey
3. Research from control variables by researchers:
- Experimental research
- Ex-post facto research
4. The research design according to its purpose:
- Descriptive research
- Comparative research
- Research associative
5. The study design according to the time dimension:
- Research statistics
- Research Cross Section
6. Design Research visits Iranian study environment can be grouped:
- Experimental Study and Field
- Experimental Laboratory