experimental method

• • Independent groups: Participants are divided into two groups. One group does the experiment with variable 1, the other group does the experiment with variable 2. Results are compared.
• • Repeated measures: Participants are not divided into groups. Instead, all participants do the experiment with variable 1, then afterwards the same participants do the experiment with variable 2. Results are compared.
• A matched pairs design is another form of independent groups design
• match pairs- 


  researchers recruit another group of participants one-by-one to match the characteristics of each member of the original group. This provides two groups that are relevantly similar and controls for differences between groups that might skew results. The experiment is then conducted as a normal independent groups design.
• Laboratory experiment: An experiment conducted in an artificial, controlled environment
• Field experiment: An experiment carried out in a natural, real-world environment
• negative of lab study is participants may be influenced by demand characteristics: They know they are taking part in a test, and so behave how they think they’re expected to behave rather than how they would naturally behave.
• Natural experiment: An experiment where the variable changes naturally and the researcher seizes the opportunity to study the effects
• Quasi experiment: An experiment that compares between two variables that cannot be changed