Sampling can be explained as a specific principle used to select members of population to be included in the study. It has been rightly noted that “because many populations of interest are too large to work with directly, techniques of statistical sampling have been devised to obtain samples taken from larger
populations.”[1]. In other words, due to the large size of target population, researchers have no choice but to study the a number of cases of elements within the population to represent the population and to reach conclusions about the population (see Figure 1 below). Figure 1. Population, sample and individual cases[2] Brown (2006) summarizes the advantages of sampling in the following points[3]: The Process of Sampling in Primary Data CollectionThe process of sampling in primary data collection involves the following stages: 1. Defining target population. Target population represent specific segment within wider population that are best positioned to serve as a primary data source for the research. For example, for a dissertation entitled ‘Impact of social networking sites on time management practices amongst university students in the UK” target population would consist of individuals residing in the UK. 2. Choosing sampling frame. Sampling frame can be explained as a list of people within the target population who can contribute to the research. For a sample dissertation named above, sampling frame would be an extensive list of UK university students. 3. Determining sampling size. This is the number of individuals from the sampling frame who will participate in the primary data collection process. The following observations need to be taken into account when determining sample size: a) The magnitude of sampling error can be diminished by increasing the sample size. b) There are greater sample size requirements in survey-based studies than in experimental studies. c) Large initial sample size has to be provisioned for mailed questionnaires, because the percentage of responses can be as low as 20 to 30 per cent. d) The most important factors in determining the sample size include subject availability and cost factors For example, for the same research of ‘Impact of social networking sites on time management practices amongst university students in the UK’ sample size could be determined to include 200 respondents. 4. Selecting a sampling method. This relates to a specific method according to which 200 university students in the UK are going to be selected to participate in research named above. 5. Applying the chosen sampling method in practice. Sampling methods are broadly divided into two categories: probability and non-probability. In probability sampling every member of population has a known chance of participating in the study. Probability sampling methods include simple, stratified systematic, multistage, and cluster sampling methods. In non-probability sampling, on the other hand, sampling group members are selected on non-random manner, therefore not each population member has a chance to participate in the study. Non-probability sampling methods include purposive, quota, convenience and snowball sampling methods. The Figure 2 below illustrates specific sampling methods belonging to each category: Figure 2. Categorisation of sampling techniques The following table illustrates brief definitions, advantages and disadvantages of sampling techniques:
My e-book, The Ultimate Guide to Writing a Dissertation in Business Studies: a step by step approach contains a detailed, yet simple explanation of sampling methods. The e-book explains all stages of the research process starting from the selection of the research area to writing personal reflection. Important elements of dissertations such as research philosophy, research approach, research design, methods of data collection and data analysis are explained in this e-book in simple words. John Dudovskiy [1] Proctor, T. (2003) “Essentials of Marketing Research”, 3rd edition, Prentice Hall [2] Source: Saunders, M., Lewis, P. & Thornhill, A. (2012) “Research Methods for Business Students” 6th edition, Pearson Education Limited [3] Brown, R.B. (2006) “Doing Your Dissertation in Business and Management: The Reality of Research and Writing” Sage Publications What is a selected segment of the population?sample: A selected segment of the population used to represent the group that is being studied (p. 24); a subset of a population. representative sample: A selected segment that very closely parallels the larger population being studied on relevant characteristics.
What is a segment of population that is targeted for study?A target audience is a segment of the population that has a specific opportunity to take action on the problem you have identified; or is specifically affected by the problem.
What is the group of units we collect data on called?The entities on which data are collected is known as variables. A data item is also called as a variable. For example, age, sex, income, etc are referred as variables. Was this answer helpful?
What is the term for the group of individuals that are studied in an experiment?Population. The entire group to be studied. Individual. A person or object that is a member of the population being studied. Sample.
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