(PD00500=Sampling the Evidence of Extension Program Impact
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PEOD5 Sampling the Evidence of Extension Program Impact 1 Glenn D. Israel 2 1. This document is PEOD5, one of a series of the A gricultural Education and Communication Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Original publication date October 1992. Revised April 2009. Reviewed June 2012. Visit the EDIS website at http://edis.ifas.ufl.edu. 2. Glenn D. Israel, associate professor, Department of Agricultural Education and Communication, and extension specialist, Program Evaluation and Organizational Development, Institute of Food and Agricultural Sciences (IF AS), University of Florida, Gainesville, FL 32611. The Institute o f Food and Agricultural Scienc es (IFAS ) is an Equal O pportunity Institut ion authorized to provide research, educa tional informat ion and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A&M University Cooperativ e Extension Program, and Boards of County Commissio ners Cooperating. Millie Ferrer-Chancy, Interim Dean Evaluating cooperative Extension programs is a process which includes gathering evidence about program impacts. One part othis process is the determination ohow much data is necessary to show whether or not a program had the intended outcome. For example, ia program on the adoption oa new technology by armers is being evaluated, should each and every armer be asked ihe or she adopted the technology or should a sample oarmers be asked the question? Using a sample can provide evidence or use in the program evaluation. A sample can also save valuable time, money, and the labor oExtension proessionals. ime is saved because ewer people, armers, 4-Hers, etc. must be inter- viewed or surveyed; thus the complete set odata can be collected quickly. Money and labor are saved be cause less data must be collected. In addition, errors rom handling the data (e.g. entering data into a computer file) are likely to be reduced bec ause there are ewer opportunities to make mistakes. Te purpose othis paper is to provide an overview osam- pling procedures or obtaining data to evaluate Extension programs. Strategies or selecting a sample will be reviewed. A second paper , Determining Sample Size, PEOD-6, should also be consulted. THE RESEARCH PROBLEM Te first step in determining the sampling procedures to be used in an evaluation is a clear statement othe research or evaluation problem. Ask yoursel“What do I want to know?” • Have the elt needs oresidents who live in Manatee County been reduced? • What practices did armers adopt as a result othe Farming Systems Research and Extension program? • Has income among households with a new home-based business increased more than those without one? Te above questions suggest that the purpose othe evaluation can vary . Te purpose may be as simple as documenting the change oindicator variables (that program activities are assumed to affect). Or, the purpose may include a more rigorous analysis, which compares changes by program participants with changes by nonpar- ticipants, to estimate the strength othe program impact. Tis type oanalysis would be neede d to answer the latter two questions. DEFINING THE POPULATION A good problem statement is necessary to identiy the population relevant to evaluating program impacts. Te population is composed othe individuals or groups that are affected by the Extension program and thus, are the ocus othe evaluation. For example, residents oManatee County or small armers in Suwannee and C olumbia
