Page 105 - DLIS401_METHODOLOGY_OF_RESEARCH_AND_STATISTICAL_TECHNIQUES

Methodology of Research and Statistical Techniques

Notes • A probability sampling scheme is one in which every unit in the population has a chance
(greater than zero) of being selected in the sample, and this probability can be accurately
determined.
• Probability sampling includes: Simple Random Sampling, Systematic Sampling, Stratified
Sampling, Probability Proportional to Size Sampling, and Cluster or Multistage Sampling.
• Snowball sampling is a special nonprobability method used when the desired sample
characteristic is rare.
• Sampling is that part of statistical practice concerned with the selection of individual
observations intended to yield some knowledge about a population of concern, especially
for the purposes of statistical inference.

6.6 Keywords

Accuracy : Accuracy refers to how close a sample statistic is to a population
parameter. Thus, if you know that a sample mean is 99 and the true
population mean is 100, you can make a statement about the sample
accuracy.
Sampling Method : Sampling method refers to the rules and procedures by which some
elements of the population are included in the sample.

6.7 Review Questions

1. What is the definition of population? Explain.
2. What is the sampling frame? Explain.
3. Write a short notes on probability and non-probability sampling.
4. Discuss an accurate sampling method of research.

Answers: Self Assessment

1. (a) Random sampling 2. (b) Systematic sampling
3. (c) Stratified sampling 4. (d) Judgment sampling
5. (b) Quota sampling

6.8 Further Readings

Books Editing scientific books and journals, 1978: Donner, M.D.
Research methods in social science, 1988: Sharma, Ram Dutt.
Research methodology, a handbook, 1989: Misra, K.P.

Online links www.emathzone.com/tutorials/basic-statistics/probability-and-nonprobability-
sampling.html
www.mathsisfun.com/accuracy-precision.html
www.en.wikipedia.org

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