Convenience, Voluntary, Simple Random Sample

1. Convenience, Voluntary, Simple Random Sample

2. Redefine as a class the following sampling techniques. • Convenience • Voluntary Response • Simple Random Sample • Choosing individuals who are easiest to reach • Individuals choose to participate in the study • A random selection of individuals where every individual has a chance of being selected.

3. Simple Random Sampling • Mr. Zummo wants to find out how chocolate affects the alertness of his 1st period students. • What would Mr. Zummo need in order to take a Simple Random Sample of his 1st period, how would he make sure he is being random?

4. Name the type of sample. • Ms. Kenaga wanted to find out more about what the seniors at Fenger High School thought about the food that is served in the lunchroom. So, she drew up a survey and handed it out to all of the senior teachers and had them give it to their class. When the teachers got to class, they gave it to their students and instructed them to take it home to bring back for extra credit, it was not for points. What type of sample is this? Voluntary Response Sample

5. What are the disadvantages of a this sampling technique? • Often times biased, if a student is going to participate they must have a strong view. • Student may just not read the questions and make stuff up. • Students may lie.

6. How could we change the scenario so it met the requirement of a SRS? This scenario would not be considered SRS because students were not required to take the survey. Since there was an option, the type of survey is considered to be “voluntary”.

7. Name the type of sample. • Ms. Stadeker wanted to go to a movie that her seniors liked but she was torn between two movies. So she decided to take a poll of a class and see what the majority was. What type of sample is this? Convenience Response Sample

8. What are the advantages of this sample? • Easy, Fast, Cheap, etc.

9. Would this scenario be considered SRS? If not, why not? • Mr. Booker wanted to do a research study on the most preferred (favorite) shoe amongst the Fenger High School senior class. He made up a non-biased survey and handed it out to all the seniors at lunch. (Assume all seniors were at lunch and none of them ditched). He looked over the answers of only the first 30 students who turned the survey into him.

10. IS NOT!!! • This is not an example of a Simple Random Sample because the students who finished the fasted were chosen over the slowest. Since the students who read at a slower pace were not given an equal opportunity, this is not considered to be a Simple Random Sample but it is considered to be a Convenience Sample.

11. Count off by fives • Guidelines • Keep it cool • 8 minutes at each station

12. Journal Topic • How can you collect data on peoples’ opinions? For example: If I wanted to find out how students in the CPS feel about the longer school day, how could I collect such information?

13. Surveys • Select a sample of people to represent a larger population • Ask the individuals in the sample some questions and record their responses • Use sample results to draw some conclusions.