Statistics How To

Effect Size > Glass’s delta Glass’s delta (Glass et al. 1981) is a measure of effect size. Glass’s delta uses only the control group’s standard deviation (SDC). This is because Glass argued that if several treatments were compared to a control group, it would be better to use just the standard deviation computed from the … Read more

Descriptive Statistics > Unimodal Distribution What is a unimodal distribution?   A unimodal distribution is any distribution with a single peak, cluster, or high point. It comes from the Latin word uni- (“one”) and Middle French modal (“measure”). The values increase at first, rising to a peak where they then decrease. The “mode” in “unimodal” doesn’t … Read more

Probability Distributions > Cauchy Distribution What is a Cauchy Distribution? The Cauchy distribution, sometimes called the Lorentz distribution Cauchy–Lorentz distribution, Lorentz(ian) function, or Breit–Wigner distribution, is a family of continuous probably distributions which resemble the normal distribution family of curves. While the resemblance is there, it has a taller peak than a normal. And unlike the normal … Read more

Statistics Definitions > Frequentist Statistics: What are Frequentist Statistics? Frequentist statistics (sometimes called frequentist inference) is an approach to statistics. Frequentist statistics uses formal frameworks and rules to conduct hypothesis tests and find p-values and confidence Intervals. Probability is defined as long-term frequency in a repeatable, random experiment [1]. The polar opposite is Bayesian statistics, … Read more

Time Plot > Contents: Order of Integration (Time Series) Order of Integration (Integrals) Order of Integration (Time Series) You may want to read this article first: What is a Unit Root? “Order of integration” is a summary statistic used to describe a unit root process in time series analysis. Specifically, it tells you the minimum … Read more

Charts and Graphs > > Causal Graph What is a Causal Graph Model? A causal graph model (also called Bayesian networks, DAGs or path diagrams) are a way to represent how causality works in terms of what causes what. These probabilistic graphical models are used to encode assumptions about data-generating processes. Independence and conditional independence … Read more

Markov Chain Monte Carlo > The Metropolis-Hastings algorithm is a popular statistical sampling method used in statistics and data science. It is a Markov chain Monte Carlo (MCMC) algorithm, meaning that it uses random samples from a probability distribution to estimate parameters. In this blog post, we will discuss what the Metropolis-Hastings algorithm is, how … Read more

Descriptive Statistics > How to Make a Relative Frequency Histogram Contents (click to skip to that section): What is Relative Frequency? Making a Table Relative Frequency Histogram How to Make a Relative Frequency Histogram: Steps What is Relative Frequency? Relative frequency is how often something happens divided by all the possible outcomes. The relative frequency … Read more

Probability and Statistics > Basic Statistics > 5 Number Summary in Excel How to find a 5 number summary in Excel A five number summary is a way to describe data. It is made up of five statistics: The median (the middle). The maximum value. The minimum value. Q1, the first quartile. Q3, the third … Read more

Statistics Definitions > Standardized Variables What are Standardized Variables? A standardized variable means something slightly different according to where you’re using it. Use in Probability and Statistics. Use in General Science (including biology). 1. Use in Probability and Statistics In statistics, standardized variables are variables that have been standardized to have a mean of 0 … Read more