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Image of a researcher AEE 578--Scientific Inquiry in Agricultural and Extension Education
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Sampling
Introduction:

Image of a magnifying glass 		Questions!   Questions!   Questions!
Do I ever get questions from people who want to conduct research using the survey technique.
  • Should I study the entire population or just a sample?
  • If I sample, how big should the sample be?
  • Are there different sampling techniques?
  • What should I do to insure that I get a "representative" sample?
  • How do I actually identify the people to incude in my study?
  • What do I do about non-respondents?
  • What response rate do I need to have a valid study?
The previous lessons have looked at the landscape of conducting educational research. In this lesson we get down to the nitty-gritty nuts and bolts of conducting educational research. This may be the most important lesson of the class from an application standpoint. Whether you study the entire population or a sample from that population you must be able to defend what you did and explain how you did it.
Learning Objectives:

Icon of a signpost 		image of a ball Determine how large a sample should be to make it scientifically acurate.
image of a ball Identify and describe four different sampling techniques.
image of a ball Demonstrate how to select a random sample.
image of a ball Identify what an appropriate response level is.
image of a ball List 10 technques for increasing response rates in survey research.
image of a ball Describe how to handle non-respondents.  
Instructional
Activities:

Icon of a computer 		image of a ball Read Chapter 6 "Sampling" in How to Design and Evaluate Research in Education (Fraenkel & Wallen).

image of a ball The StatPac web site provides a good overview of sampling.

image of a ball Watch this video that illustrates simple, systematic, and stratified sampling.

image of a ball  How big should the sample be?
image of a ball Typically, in selecting a sample, you will have a numbered list of names. In order to determine which names should be selected you could use a table of random numbers or use the online randomization program (the latter is much easier).

image of a ball One of the most widely cited articles in all of agricultural and extension education is an article by Miller and Smith that was published in the 1983 Journal of Extension titled, "Handling Nonresponse Issues." See what they had to say.

image of a ball Also on the issue of non-response situations is this article by Lindner, Murphy, and Briers.
(also available at http://pubs.aged.tamu.edu/jae/pdf/Vol42/42-04-43.pdf).

image of a ball Do Incentives increase response rates for surveys?

image of a ball Is there a difference in response rate between using stamped or metered reply envelopes?

image of a ball View a PowerPoint presentation on Sampling.
Review:

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 Image of a blue ball The publisher of the textbook has some excellent information to support the text; you should check it out:
 Image of a blue ball Visit the text site and complete the multiple choice questions for Chapter 5

Additional Resources:
image of a gift
 		Image of a blue ball IF you want to see more (NOT required):
Assignments:               
Icon of note pad 		Image of a blue ballComplete the sampling worksheet. 

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