PSY 2174 Lecture Notes - Lecture 4: Energy Medicine, External Validity, Simple Random Sample

• School: University of Ottawa
• Department: Psychology
• Course: PSY 2174
• Professor: Heather Poole

Document Summary

Population: the entire group of individuals you could measure you could measure on a variable. Sample: the group of individuals/scoured that you select ( hopefully randomly) from the population and measure in your experiment. We use scored of samples to estimate scores of populations. Expected behaviour of a population in interpolated from the sample. Comparing self - reported stress levels in n. america. Generalizes level from the samples to the populations. Critical: we can only generalize out findings if our sample is representative of the population. Even if the selection is not generalizable, the study can still have value. Can be caused by researcher using sample of convenience. The groups are not balance with respect to certain factors. External validity threatened in cases of selection bias. But random assignments to condition can increase - internal validity. Should be enough that it is not random. Can rarely randomly select, but can always randomly assign.