2022 Introduction to Statistics in Research Mitchell 2nd ed

I N T R O T O R E S E A R C H : D A T A V I S U A L I Z A T I O N & C O M M O N S T A T T E S T S

Star-Trek – Teach yourself statistics Here is the link to the website: https://stattrek.com/experiments/experimental-design.aspx This website has a great video (about 11 minutes) that covers many of the topics discussed in this Nuts & Bolts section.

Probability and Non-probability Sampling Most researchers want the sample to represent the entire population. Sampling methods are generally divided into two categories of probability sampling and non-probability sampling. In probability sampling, each member has a known opportunity to belong to the sample. In non-probability sampling, there is no specific probability of the individual to be part of the sampling. Example: Assume your population interest is college professors. If you only invite professors from your college to participate, that's a non-probability sample because other college professors have no chance to participate. The main advantage of probability-based sampling over non-probability sampling is that probability sampling lets you calculate the margin of error. An easier explanation is that you can't generalize to the larger population with a non-probability sampling method. A non-probability sampling method will often work with qualitative research because the purpose is different. Qualitative researchers often use purpose-sampling, a non-probability sampling technique because the researcher chooses participants because they have specific expertise (like global leaders). Quiz

Types of non-probability sampling

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convenience sampling consecutive sampling

• judgmental sampling ( sample chosen based on researcher’s knowledge – this technique often has a high amount of ambiguity) • quota sampling (a way to divide the population into strata or groups, i.e. male and female leaders) • snowball sampling (often used when samples are difficult to locate. So once researchers find a suitable subject, they ask the subject for assistance in seeking similar subjects). Advantages: Responses are quicker and more cost-effective. Often respondents are more motivated to participate because they were not selected randomly. Very practical and if done correctly, it can produce similar results.

Disadvantages: Very useful when the population is diverse. Yields data in the form of numbers.

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