PSY 3213C Lecture 9: sampling
Document Summary
Beginning study: usa today poll cannot be generalized b/c group is large, but not representative. Representative sample: all member have an equal chance of being included in the sample: simple random sample: random process to pick members of the population so that each member has an equal chance of being selected. Exercise: tossing coin 25 times and seeing what you get. Randomly get longer strands of the same response: cluster sampling: clusters of participants are sampled randomly and then all individuals in the selected clusters are included. Scanning brains men and women under opioid dependence while viewing baby pictures. Controlled participants showed a strong response in ventral striatum, opiod dependents did not. Problems with the study: couldn"t assign participants randomly so not confident if the 2 groups were different or not. Use random process to get 200 random books. Pearson product correlation coefficient is a measure of linear association.
