Sampling from Populations
State whether each of the following examples describe probability or nonprobability sampling and state the type of sampling method used:
To select a sample of children for a behavioral study, a researcher places ads in the local area asking for any parents with children to please consider volunteering for the study. The children of any parents who replied to the ads were included in the sample.
A teacher identifies all freshman, sophomore, junior, and senior students at a local high school. She then selects a sample of 10 students in each class using a random sampling procedure before combining all selected students into one larger sample of 40 total students.
A researcher in a brain imagining study selects a sample of participants to test for differences in process information speed. The number of men and women in the population was unknown, so the researcher selected an equal number of men and women for her study to ensure that sex was equally represented.
A professor selects a sample of participants from his class by selecting the first participant using a random procedure, then selecting every third student listed in the class roster.
A researcher wants to study the growing issue of bullying behavior in New York State (NYS) public high schools. To select a sample, the researcher first breaks up the population by district. Then she chooses a sample of districts by selecting four districts that she believed were representative of the characteristics of students in the larger population of NYS public schools. Once those districts were selected, then all students in those districts were selected for the sample. All districts that were not selected were omitted from the sample.
A CEO gains access to the names of all employees in his company, then uses a random procedure to select a sample of 100 employees to complete an employee satisfaction survey.
Please read chapter 5 from the required reading from the book
Privitera, G. J. (2018). Research Methods for the Behavioral Sciences. ( see power point)
Watch on you tube the Video https://www.youtube.com/watch?v=0Pd3dc1GcHc “What is a T-Test?
