NUR 80A/B Chapter Notes - Chapter 8: Null Hypothesis, Statistical Hypothesis Testing, Sampling Distribution
21 Feb 2016
School
Department
Course
Professor
Document Summary
Inferential statistics, which are based on the laws of probability, provide a means for drawing conclusions about a population, given data from a sample. Random sampling is the best means for securing samples that are representative of the population. Inferential statistics are based on the assumption of random sampling from populations: even with random sampling, sample characteristics seldom identical to those of the population. Sample statistics fluctuate and are unequal to population parameter because of sampling error. To understand the logic of inferential statistics, we must perform mental exercise: consider drawing a sample of 25 students from the population, calculating a mean test score, replacing the students, and drawing a new sample. Statisticians demonstrated that: sampling distributions of means follow normal distribution, mean of a sampling distribution for an infinite number of sample means. Sd from the mean distribution which is called the standard error of the mean (or sem)
