Two Way ANOVA in R

Introduction The more advanced methods in statistics have generally been developed to answer real-world questions, and ANOVA is no different. How do we answer questions in the real world, as to which route from home to work on your daily commute is easier, or How would you know which air-conditioner to choose out of a […]

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Animated: Mean and Sample Size

A quick experiment in R can unveil the impact of sample size on the estimates we make from data. A small number of samples provides us less information about the process or system from which we’re collecting data, while a large number can help ground our findings in near certainty. See the earlier post on […]

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Simple Outlier Detection in R

Outliers are points in a data set that lie far away from the estimated value of the centre of the data set. This estimated centre could be either the mean, or median, depending on what kind of point or interval estimate you’re using. Outliers tend to represent something different from “the usual” that you might […]

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Power, Difference and Sample Sizes

In my earlier posts on hypothesis testing and confidence intervals, I covered how there are two hypotheses – the default or null hypothesis, and the alternative hypothesis (which is like a logical opposite of the null hypothesis). Hypothesis testing is fundamentally a decision making activity, where you reject or fail to reject the default hypothesis. […]

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