Statistics - Analysis of variance (Anova)

Card Puncher Data Processing

About

Anova is just a special case of multiple regression.

There're many forms of ANOVA. It's a very common procedure in basic statistics.

Anova is more Appropriate when:

It's most common application is to analyze data from randomized controlled experiments (ie experimental research) but it can be used in non-experimental context as well.

If we only generate two group means (only 2 means) then we can just do t-tests :

Anova is used more specifically for randomized experiments that generate more than 2 two group means (two means).

During an experimental research, if two group means are generated and that we want to compare those group means, then we'll engage in ANOVA.

  • if the groups are all independent then we call that a “between groups ANOVA”.
  • if the groups are all coming from the same subjects, then we call that “repeated measures ANOVA”.

During Independent t-test, there is multiple pairwise comparisons and this is a tedious task. There should be one procedure to do that in one step, and that's ANOVA.

Test

ANOVA typically involves NHST, but it doesn't have to

The NHST test statistic is an F-test or F-ratio.

An ANOVA will tell with the F-ratio if:

  • there is an effect overall
  • there is significant difference somewhere

The Post-hoc tests is used to figure out exactly where there are significant differences.

Type

True / False

True

Anova is:

  • used when the independent variables are categorical and the dependent variable is continuous
  • a form of multiple regression where the predictors are not correlated
  • an analysis used when the relationship between the independent variable and the dependent variable are linear and additive

False

Anova is an analysis used when the variables are correlated.

Documentation / Reference





Discover More
Thomas Bayes
Data Science - History

A brief history of data analysis Fisher proposed a design of experiments along with his statistical tests ANOVA, and Fisher's exact tests. He's also credited with the quotation, “Correlation does...
Card Puncher Data Processing
R - Anova

To compare the gain scores across all groups, use anova First, check the homogeneity of variance assumption:
Card Puncher Data Processing
Statistics

is a scientific discipline devoted to the study of data. is the art of extracting information from data. From Data to Information to Knowledge. No learning. lies lies, damned lies, and statistics....
Thomas Bayes
Statistics - (F-Statistic|F-test|F-ratio)

The NHST anova statistic test is an F-test or F-ratio. It's what you observe in the numerator relative to what you would expect just due to chance in the denominator. The f statistic is the statistic...
Thomas Bayes
Statistics - (Interaction|Synergy) effect

In a multiple regression, is assumed that the effect on the target of increasing one unit of one predictor (is independent|has no influence) on the other predictor. If this is not the case, sharing a...
Thomas Bayes
Statistics - Dummy (Coding|Variable) - One-hot-encoding (OHE)

Dummy coding is: a classic way to transform nominal into numerical values. a system to code categorical predictors in a regression analysis A system to code categorical predictors in a regression...
Thomas Bayes
Statistics - Factorial Anova

A factorial ANOVA is done when the independent variables are categorical. By adding a second independent variable, we are entering in factorial ANOVA. N Independent Variables (IVs). Variables that...
Thomas Bayes
Statistics - Generalized Linear Models (GLM) - Extensions of the Linear Model

The Generalized Linear Model is an extension of the linear model that allows for lots of different,non-linear models to be tested in the context of regression. GLM is the mathematical framework used in...
Thomas Bayes
Statistics - Post-hoc test

In an anova, the Post-hoc tests is used to figure out exactly where there are significant differences.
Thomas Bayes
Statistics - independent t-test

A dependent t-test is appropriate when you want to compare two independent samples. (two completely different groups of entities). For examples: if we want to compare one condition to another as men...



Share this page:
Follow us:
Task Runner