Statistics Definitions > What is a Representative Sample? A representative sample is where your sample matches some characteristic of your population, usually the characteristic you’re targeting with your research. For example, if you’re conducting a survey about how women’s experience…

## Composite Reliability: Definition

Reliability and Validity > Composite reliability (sometimes called construct reliability) is a measure of internal consistency in scale items, much like Cronbach’s alpha (Netemeyer, 2003). It can be thought of as being equal to the total amount of true score…

## Research Variable / Study Variable

Types of Variables > Research Variable / Study Variable A research variable (also called a study variable) is an informal term that means any variable used in research that has some kind of cause and effect relationship. A research/study variable…

## Intervention Fidelity in Research

RCTs > Intervention Fidelity in Research answers the question “Was the intervention delivered as intended?” It’s a measure of how well the results of an intervention or experiment matched up to what was actually planned. An intervention is some form…

## k-NN (k-Nearest Neighbor): Overview, Simple Example

Nearest Neighbor matching > k-NN (k-Nearest Neighbor) K-nn (k-Nearest Neighbor) is a non-parametric classification and regression technique. The basic idea is that you input a known data set, add an unknown, and the algorithm will tell you to which class…

## Unstandardized Coefficient

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…