tailieunhanh - Lecture Research methods - Chapter 5: Selecting samples and negotiating access

Lecture Research methods - Chapter 5 presents the following content: The need to sample, overview of sampling techniques, deciding on a suitable sample size, choosing the appropriate sampling technique, checking the sample representativeness, strategies to gain access. | Selecting Samples and Negotiating Access Samuel K. Frimpong (.) Outline presentation The need to sample Overview of sampling techniques Deciding on a suitable sample size Choosing the appropriate sampling technique Checking the sample representativeness Strategies to gain access What is Sampling? Sampling refers to the techniques that enable you to reduce the amount of data you need to collect by considering only data from a subgroup rather than all possible cases or elements. Population Sample Sampling vs. Census A census involves collecting data from all members of a population. A sample is a relatively small subset of the population that is selected to be representative of the population’s characteristics. The Need to Sample It would be impracticable for you to survey the entire population Your budget constraints prevent you from surveying the entire population Your time constraints prevent you from surveying the entire population You have collected all the data but need the . | Selecting Samples and Negotiating Access Samuel K. Frimpong (.) Outline presentation The need to sample Overview of sampling techniques Deciding on a suitable sample size Choosing the appropriate sampling technique Checking the sample representativeness Strategies to gain access What is Sampling? Sampling refers to the techniques that enable you to reduce the amount of data you need to collect by considering only data from a subgroup rather than all possible cases or elements. Population Sample Sampling vs. Census A census involves collecting data from all members of a population. A sample is a relatively small subset of the population that is selected to be representative of the population’s characteristics. The Need to Sample It would be impracticable for you to survey the entire population Your budget constraints prevent you from surveying the entire population Your time constraints prevent you from surveying the entire population You have collected all the data but need the results quickly Sampling Design Process The sampling design process involves answering three questions: Should a sample or a census be used? If a sample, then which sampling approach is best? How large a sample is necessary? Steps to obtain representative sample 1. Define the target population. 2. Choose the sampling frame. 3. Select the sampling method. 4. Determine the sample size. 5. Implement the sampling plan. Defining Target population and Sampling Frame Target population is the complete group of objects or elements relevant to the research project. They are relevant because they possess the information the research project is designed to collect. Sampling frame is a complete list of all the elements in the population from which the sample is drawn Sampling Techniques/Methods Probability or representative sampling: each element of the population has a known, but not necessarily equal, probability of being selected in a sample. Non-probability or judgmental sampling: not every .