Regression Analysis > Unstandardized coefficients are ‘raw’ coefficients produced by regression analysis when the analysis is performed on original, unstandardized variables. Unlike standardized coefficients, which are normalized unit-less coefficients, an unstandardized coefficient has units and a ‘real life’ scale. An…

## Relative Absolute Error

Statistics Definitions > What is Relative Absolute Error? Relative Absolute Error (RAE) is a way to measure the performance of a predictive model. It’s primarily used in machine learning, data mining, and operations management. RAE is not to be confused…

## Uncertainty in Statistics

Statistics Definitions > In the real word, uncertainty (sometimes called error or bias) is a part of everyday life, but in statistics we try to quantify just how much uncertainty is in our experiment, survey or test results. The two…

## Quasi-Statistical: Definition

Statistics Definitions > “Quasi-Statistical” is a somewhat loose term that could refer to: Quasi-experiments Becker’s Quasi-statistics 1. Quasi-Experimental Design A quasi-experimental design is missing one or more key components of a solid experimental design, which are: Pre-post test design. Treatment…

## Between Group Variation: Definition, Formula

ANOVA > Between group variation is used in ANOVA (analysis of variance) to measure variation between separate groups of interest. Unlike within group variation, where the focus is on the differences between a population and its mean, between group variation…

## Scale Factor: Definition, Examples

Statistics Definitions > A scale factor is a number which multiplies (“scales”) a quantity. For example,the “C” in y = Cx is the scale factor for x. If the equation were y = 5x, then the factor would be 5.…

## Waring Distribution: Definition

Probability Distributions > The Waring distribution is a generalization of the Simon-Yule distribution. To put that another way, the Simon-Yule is a special case of the Waring distribution when the parameters take on certain limiting values. The Waring has two-parameters…

## Ceiling Effect: Simple Definition, Examples

Statistics Definitions > What is the Ceiling Effect? A ceiling effect happens when your questionnaire or test components/problems aren’t hard enough; An artificially low ceiling is created that is easy to achieve. If it exists in your test or survey,…

## Error Bar: Definition

Statistics Definitions > What is an Error Bar? An error bar is a (usually T-shaped) bar on a graph that shows how much error is built in to the chart. The “error” here isn’t a mistake, but rather a range…

## Directional Test

Hypothesis Testing > A directional test is a hypothesis test where a direction is specified (e.g. above or below a certain threshold). For example you might be interested in whether a hypothesized mean is greater than a certain number (you’re…