Puzzles In Sampling Design And Experimentation Example

Puzzles In Sampling Design And Experimentation Example Puzzles In Sampling Design And Experimentation – Coursework Example Puzzles in sampling design and experimentation May 23, Puzzles in sampling design and experimentation A team of ecologists is studying effects of suburban neighborhoods on stream ecology and due to limited time and finances, has decided to collect data from two sample points on a single stream. Measurables are temperature, dissolved oxygen, and aquatic macroinverterbrates. The design will not give the researchers defensible scientific results because of reliability and validity issues that arise from sampling strategy. Quantitative scope of the study requires reliability and validity that the design lacks. A representative sample is one of qualities of a quantitative study this lacks in the research. Using a single stream ignores data from other streams in the neighborhood and should differences exist in the streams’ composition, the results will not reflect on the data. Use of two sample points is another issue that undermines scientific quality of the study. Even a single st ream may have different features along its flow and multiple data points are necessary for capturing information at the different points. The arbitrary selection of two data collection points also identifies threat to bias, possibly because of convenience. Internal and external threats to reliability therefore exist, extend to validity of the study’s results, and undermine its scientific quality (Cohen, Manion, & Morrison, 2013).Use of many streams for the study and many data points from each stream would improve the design, assuming that resource and time constraints are resolved. Reliance on secondary data can be an alternative if the constraints still exist. Probability sampling of data points, such as use of stratified random sampling with demographic factors and existing literature on features of streams as bases for defining strata, would also improve the design (Cohen, Manion, & Morrison, 2013).ReferenceCohen, L., Manion, L., & Morrison, K. (2013). Research methods in education. New York, NY: Routledge.