PSY 250 Lecture Notes - Lecture 18: Sample Size Determination, Alternative Hypothesis, Effect Size
Document Summary
Inferential stats inferring something about the population from the sample. Inferential statistics are necessary because the results of a given study are based on data obtained from a single sample. Most of the time, the sample is smaller than the population, and we don"t always get a representation of the whole population. Data are not based on an entire population of scores. Inferential statistics are used to determine whether study results match what would happen if we were to conduct the experiment with multiple samples. If we continue to pull mean values from multiple samples, on average we would get the mean of the population; cannot do in real life. Need inference to determine whether sample reflects the population (sampling error?) If you use probability sampling, your sampling error should be lower. Or that the effect or relationship exists but in opposite direction of alternative.
