Sampling Flashcards
What is a Simple Random Sample?
A sample in which every individual has an equally likely chance of being chosen; every sample of size ‘n’ has an equally likely chance of being chosen. It can be referred to as ‘SRS’.
What is a Stratified Random Sample?
A sample in which the population is split into groups known as ‘strata’. The strata are formed based on the individuals’ shared attributes and characteristics. After stratifying, you take an SRS of each strata.
What is a Voluntary Response Sample?
A poor sampling technique in which the individuals elect to be a part of the survey. It is a poor sampling technique because the only people who volunteer, will be the people who feel the very strongest on the matter.
What is a Convenience Sample?
A poor sampling technique in which the data is obtained in the most convenient way possible, which will not account for any lurking variables in the sample. EX: A teacher asking only the students who will be in his room during the day.
What is Cluster Sampling?
A sampling technique similar to Stratified Random Sampling in that the population is divided into groups. With Cluster Sampling, you actually just select one whole group instead of performing SRS on each group.
What is Multistage Sampling?
A using multiple sampling to create a sample.
What is Common Response?
When changes in both “x” and “y” are caused by a lurking variable “z”. Ex. In a study regarding the relationship between Mr. Hopkin’s happiness level and his student’s grades, a sudden leak of asbestos in the school can both decrease Mr. Hopkin’s happiness level and keep his students from having good grades.
What is Confounding?
When the effects of two variables (lurking or explanatory) on a response variable cannot be distinguished. Ex. In a study regarding the relationship between Mr. Hopkin’s happiness level and his student’s grades, the gender ratio of the students and their heights are confounding because they do not influence Mr. Hopkin’s happiness level.
What is Causation?
When an increase in “x” causes an increase in “y”. Ex. In a study regarding the relationship between Mr. Hopkin’s happiness level and his student’s grades, an increase in a student’s grades may increase Mr. Hopkin’s happiness level.
What is a Lurking Variable?
A variable that is not recorded in the study but may still influence the relationship between variables in the study. Ex. In a study regarding the relationship between Mr. Hopkin’s happiness level and his student’s grades, a lurking variable may be whether or not he drank his daily Kickstart.
