ANALYSIS OF VARIANCE (ANOVA)

ANALYSIS OF VARIANCE (ANOVA)

The most used statistical technique in psychological research. (Experimental, Quasi-Experimental & Comparative research designs)

ANALYSIS OF VARIANCE (ANOVA)

Similar to the function of T-test (Ability to rule-out if there is significant difference between means) but more capable of analyzing complex datasets

1. It imposes no restriction on the number of means. Instead of asking whether two means differ, we can ask whether three, four, five, or k means differ.

2. It allows us to deal with two or more independent variables simultaneously, asking not only about the individual effects of each variable separately but also about the interacting effects of two or more variables.

The reputation of usefulness of ANOVA can be attributed to two things: ??

1. Data should be NORMAL 

2. Members of each group to be compared are randomly selected 

3. IV should be Nominal from while DV is in Interval/Ratio

What are the requirements (3) in using ANOVA?

One-way ANOVA

Two-way ANOVA

Two types of ANOVA

ONE WAY ANOVA

Anova-Used when there is a single IV with many levels (3 or more) that is tested if has a significant effect to the criterion (DV).

TWO WAY ANOVA

Used when there are two IVs. You can find the Individual effect of each Variable and its interacting effect to the criterion (DV).

• The interpretation of the analysis of variance can be difficult because 3 or more groups are being compared.

• ANOVA just tells you if there is significant difference among the groups that exists, but it doesn’t know which of the three or more groups is significantly different from the other groups.

LIMITATIONS OF ANOVA?

Post Hoc Analysis (Multiple Comparisons)

Statistical Treatment used to identify the specifics on the differences between the groups included in the study.

Tukey’s HSD (honestly significant difference)

Example of Post Hoc Analysis

Tukey’s HSD (honestly significant difference)

One of the most useful tests for investigating multiple comparison of means.

MANOVA (Multiple Analysis of Variance)

What if there is a 3 or more IVs? What statistical technique should we use?

Effect

What are we looking for in ANOVA?

Multiple Analysis Covariance

Meaning of MANCOVA?

TWO-WAY ANOVA

An inferential statistics that analyze data of research that has the goal of seeing the effect of two nominal variable (IV/Factor) to a single criterion (DV) which is in ratio or interval form.

1. You can know the individual effect of the first factor variable

2. You can know the individual effect of the second factor variable

3. You can know the interaction (Combined) effect of the two variables

What can be known if we implement two-way ANOVA in our data?

INTERACTION EFFECT

A situation in which the combined effect of two variables is greater than the sum of the effects of each of the two variables acting.

Experimental studies

Two-way ANOVA, like other forms of ANOVA, are ideally suited to randomized _____________. But it can also be used on quasi-experimental and comparative studies.

Multiple Regression

ANOVA is very closely related to _____________ which may be preferred for survey-type data

TRUE

TRUE OR FALSE

The independent (factor) variables should consist of relatively small number of categories otherwise the data analysis will be exceedingly cumbersome.

2 levels

What is the minimum categories of Two-way ANOVA?

Minimum of 3 questions

What is the minimum question in Two-way ANOVA?

3 paragraph

• 1 = effect of IV1 to the DV

• 2 = effect of IV2 to the DV

• 3 = interaction effect of the variables

How many paragraphs should the Two-way ANOVA have?