Statistical hypothesis testing
In statistical hypothesis testing, a result has statistical significance when it is very unlikely to have occurred given the null hypothesis (simply by chance alone). More precisely, a study's defined significance level, denoted by , is the probability of the study rejecting the null hypothesis, given that the null hypothesis is true; and the p-value of a result, , is the probability of obtaining a result at least as extreme, given that the null hypothesis is true. The result is statistically significant, by the standards of the study, when . The significance level for a study is chosen before data collection, and is typically set to 5% or much lower—depending on the field of study. In any experiment or observation that involves drawing a sample from a population, there is always the possibility that an observed effect would have occurred due to sampling error alone. But if the p-value of an observed effect is less than (or equal to) the significance level, an investigator may conclude that the effect reflects the characteristics of the whole population, thereby rejecting the null hypothesis. This technique for testing the statistical significance of results was developed in the early 20th century. The term significance does not imply importance here, and the term statistical significance is not the same as research significance, theoretical significance, or practical significance. For example, the term clinical significance refers to the practical importance of a treatment effect. (Wikipedia).
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When considering what statistical significance really means, we should know that: (a) there is nothing magical about p = .05, (b) probability does not tell us what we often think that it does, and (c) we need to report effect size, confidence intervals, and specific p values to understan
From playlist Statistical Significance vs. Effect Size
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It is very important that we understand what is meant by the phrase “statistically significant difference.” We know that significance is indicated by a p value, but what does that tell us and not tell us? Statistical significance tells us that the differences that we found are unlikely to
From playlist WK8 Statistical Hypothesis Testing (NHST) - Online Statistics for the Flipped Classroom
Statistical Significance and p-Values Explained Intuitively
If you’ve ever seen a news story about a scientific study, you’ve probably heard something like “statistically significant results.” More likely than not, what this is referring to is a scientific study that found something like p is less than .05. In this video I’m going to do two things
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Please Subscribe here, thank you!!! https://goo.gl/JQ8Nys Populations, Samples, Parameters, and Statistics
From playlist Statistics
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From playlist Statistics (Full Length Videos)
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From playlist Assumptions, Significance, & Effect Size Wrap-Up (WK 16 - QBA 237)
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Two drugs are being for their effectiveness. The first study found a statistically significant difference between the experimental and placebo groups. The second study did not find a statistically significant difference. If one study is significant and the other is not, is the drug in the
From playlist Assumptions, Significance, & Effect Size Wrap-Up (WK 16 - QBA 237)
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The effect size is a standardized measure of the size of an effect; the difference between means. Dr. Daniel uses a business example to show how a statistically significant study and a non-significant study both actually show the same findings. Reporting the effect size clarifies what sign
From playlist Basic Business Statistics (QBA 237 - Missouri State University)
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From playlist Hypothesis Testing Introduction WK 14 QBA 237
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The third of the five steps of hypothesis testing is to Select a Criterion for Significance. Dr. Daniel begins with “placing your bets before the horses run” to avoid exploratory data mining. There are three ways in which we might establish significance. Each gives us the same outcome in d
From playlist Hypothesis Testing Introduction WK 14 QBA 237
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From playlist Basic Business Statistics (QBA 237 - Missouri State University)
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From playlist Statistics Lecture Videos
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