It is extremely important for us to know how the study was designed to understand the quality of the study
- observer observes whats happening
- measures things of interest and draws conclusions
- Observes a part of population
- We donot influence or change the conditions
- Eg : Observing moving cars on the main road, An opinion survey asking questions about how people liked the most recent documentary
- Observational studies are less expensive than exp studies
- Observational studies may take years or even decades to complete the study.
- Here we manipulate a variable and see how our manipulation affects other variables
- It is sometimes known as scientific study
- The experimental study involves two groups — experiment group and control group. Control group is the group in the study that does not receive treatment by the researchers
- The most common type of control group is one held at ordinary conditions so it doesn't experience a changing variable. For example, If you want to explore the effect of salt on plant growth, the control group would be a set of plants not exposed to salt, while the experimental group would receive the salt
- Eg : We divide people into two groups, A and B. We ask A to go for a walk every morning and B to just sit at their homes and do their regular thing and observe the heart rate of both the groups
- Here we manipulated the variable "physical activity"
- We then tried to analyse the cause effect relationship of how it affected the heart rate
- Evidence provided by the experimental study is considered to be stronger than the observational study.