Re:Topic 2 DQ 2
Simple Random is when everyone in the population has a chance to be picked. An example would be for instance the gifts that are given away at baby showers. Every attendee at the baby shower puts their name into a bowl, there is to be 6 winners total. One name is drawn from the bowl at a time, and then the same name is placed back into the bowel for the next draw. They continue to pick names until 6 winners are drawn. Cluster sampling is used when studying a certain population. For example studying homeless people across the country rather than studying a few homeless in every town. A number of towns are selected and a significant number of homeless
people are interviewed in each one. Stratified sampling would be when a researcher selects a population and then separates the population into subgroups. From each subgroup final subjects are chosen. An example would be University studies that are organized by a college class and then divided into freshmen, sophomores, juniors, and seniors. Next a certain amount of students are selected from each subgroup for the final sample. A Random Sample would be when a population is selected and the subjects from that population are randomly chosen. Everyone in that population has an equal chance to be chosen. Such as if a student has 3 separate boxes of red, green, and blue marbles. He mixes the contents of all 3 boxes together and selects 16 marbles without looking to get a random sample. A Systematic sample happens when there is system to the way a sample is chosen. An example is a supermarket wants to study purchase habits of consumers. They choose every 12th customer that enters to conduct the study. Finally a Convenience sample is a sample that is taken from a group that is easily accessed. For instance passing out a survey to coworkers in your department because they can be easily accessed and this usually produces a higher response rate. This sample is convenient.