3. What is Variance?
• The difference between an expected and actual
result such as between a budget and actual
expenditure.
• Statistics: The arithmetic mean of the squares of the
deviations of all values in a set of numbers from
their arithmetic mean.
27. What is the difference between one way
and two way Anova?
28. What is the difference between Anova and
t test?
Editor's Notes
Definition of Analysis of Variance
Analysis of variance may be defined as a technique which analyses the variance of two or more comparable series (or samples) for determining the significance of differences in their arithmetic means and for determining whether different samples under study are drawn from same population or not, with the of the statistical technique, called F – test.
In statistics, the two-way analysis of variance (ANOVA) is an extension of the one-way ANOVA that examines the influence of two different categorical independent variables on one continuous dependent variable
A two-way ANOVA has two factors (independent variables) and one dependent variable. For example, time spent studying and prior knowledge are factors that affect how well you do on a test. A three-way ANOVA has three factors (independent variables) and one dependent variable.
The two-way ANOVA compares the mean differences between groups that have been split on two independent variables (called factors). The primary purpose of a two-way ANOVA is to understand if there is an interaction between the two independent variables on the dependent variable.
In statistics, the two-way analysis of variance (ANOVA) is an extension of the one-way ANOVA that examines the influence of two different categorical independent variables on one continuous dependent variable.
Interpret the key results for Two-way ANOVA
Step 1: Determine whether the main effects and interaction effect are statistically significant.
Step 2: Assess the means.
Step 3: Determine how well the model fits your data.
Step 4: Determine whether your model meets the assumptions of the analysis.
A one-way ANOVA only involves one factor or independent variable, whereas there are two independent variables in a two-way ANOVA. ... In a one-way ANOVA, the one factor or independent variable analyzed has three or more categorical groups. A two-way ANOVA instead compares multiple groups of two factors.
t-test & ANOVA (Analysis of Variance) ... The t-test is a method that determines whether two populations are statistically different from each other, whereas ANOVA determines whether three or more populations are statistically different from each other.