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

Nuts and Bolts of Statistics – Part 1 (with updates!)

So... it's been a while since you looked at statistics. And some of the definitions might be more difficult to recall. Let's review a few key concepts and definitions.

1) When you ask a question like: "What is the average of...? or "What is the proportion of ...? - You are interested in the population characteristic.

2) A population characteristic is a number that describes the entire population, whereas,

3) A statistic is a number that describes a sample. Remember, a "sample" is just part of the population that is selected for the study.

Social and Behavioral Science are criticized for WEIRD sampling

“The social and behavioral sciences have been criticized for relying too heavily on samples from WEIRD – Western, educated, industrialized, rich, and democratic – populations. About 80% of study participants come from these WEIRD populations but represent only 12% of the world’s population” (Adams & McGuire, 2022, p. 120).

Which approach to use?

Consider - What's the difference between an experiment and an observational study? In an experiment , the researcher determines who will be in what experimental groups and what the experimental conditions will be. In an experiment, it is important to have comparable experimental groups. In an observational study , the person carrying out the study does not determine who will be in what groups. Additionally, the purpose of an observational study is to collect data that will allow you to learn about a single population or about how two or more populations will differ. Observational studies can be retrospective (backward-looking) and prospective (forward- looking). In an observational study, it is important to obtain a sample that represents the population. Do not use an observational study to draw a cause-and-effect conclusion. Cause-and- effect belongs with an experiment.

Self-Assessment: Observational Study or Experiment

In the article, “The ‘CSI Effect’ – Does It Really Exist?” (National Institute of Justice [2008]: 1-7), the author speculates that watching crime scene investigation TV shows may be associated with the kind of high-tech evidence that jurors expect to see in criminal trials. Do people who watch such shows on a regular basis have higher expectations than those who do not watch them? Would a researcher conduct an observational study or an experiment?

Answer: Observational study

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