Chapter 10 - Non Experimental designs Flashcards
What are the 2 basic requirements for experimental researcg?
- Manipulation of one variable (random assignment of participants to each level of the ind.v)
- Control of other extraneous variables
How is a study called when neither of the 2 requirements for being an experiment are met?
Non-Experimental design
How do we call a study that is non experimental but makes an effort to control for confounds?
Quasi-Experimental design
What is the main difference between non-experimental and quasi-experimental designs?
The degree to which confounding is limited
How are groups formed in nonex and quasi designs?
The levels of the indv are not manipulated (random assignment), they are pre-existing
How are between groups nonexperimental and quasi designs called?
Non-equivalent group designs
What is assignment bias?
When the researcher has no control over the assignment of participants into a specific group
How do we label treatments and observations to illustrate a study?
treatment: X
Observations: O
Ex: OOO X OOO
What is the difference between Pretest-Posttest and pre-post desings?
Pretes-posttest has a control group, while pre-port has none
What are cohorts in developmental studies?
Participants from a certain generation = one cohort
What are cohort effects?
Confounding variable - not all participants from different cohorts had the same experiences in life; could influence the results
What are differential effects?
Groups may experience different history effects during experiments; confounding variable
