Instructor: William P. Dunlap Book: Tabachnick & Fidell (1989). Using multivariate statistics. Grading: Homework and Take Home Final Homework: All homework must be turned in by the end of the course.
Overview of Multivariate Methods
Techniques that treat multiple DV's simultaneously
Control of Type I errors across DV's
Perhaps a better understanding of complex relationships between DV's
Brief outline of multivariate methods
Hypothesis testing techniques
Canonical correlation
MANOVA & Discriminant analysis
Relations to multiple regression
Relations to ANOVA
Relations to Chi-square
Discriptive techniques
Factor analysis
Cluster analysis
Matrix Algebra (Just enough to get by)
Matrices, vectors, & scalars
Matrix addition & subtraction
Transpose of a matrix
Matrix multiplication
Row by column
Requirements for multiplication
A*B does not equal B*A
Raw data matrix, D; Matrix of standard scores, Z
R=Z'Z(1/N)
VC the variance-covariance matrix
Simultaneous equations, C*x=y
Matrix inverses (how to divide in matrix algebra)
Determinants (Multivariate variances)
2X2 matrices
3X3 matrices (and larger)
Cofactors and the change of sign
The inverse, X-1
Transpose of the cofactor matrix divided by determinant
The identity matrix; X*X-1 = X-1*X = I
Solutions to simultaneous equations; x=C-1*y
Eigenvalues and eigenvectors
Xv=cv; the defining equation
Hotellings method
Normalizing a vector
Best fitting ellipses & ellipsoids
Centile contours (centours)
Axes of ellipsoids are eigenvectors
Eigenvalues represent explained variance
Brief Review of Multiple Regression
Why Multiple Regression is a Univariate Technique
Concept of the Best Linear Composite of Predictors
Normal Equations - Solution by Matrix Inversion
Inverse of the Correlation Matrix
Types of Multiple Regression
Standard (preferred)
Stepwise
Problems
Multivariate Normality
Multicollinearity
Singularity
Outliers
Factor Analysis
Principal Component Analysis
Eigenvectors of Correlation Matrix are Factors
Eigenvalues are the Variance Explained
Factor Weights -- Eigenvectors Normalized to 1/Lambda
Factor Loadings -- Eigenvectors Normalized to Lambda
Number of Factors
Eigenvalues greater than 1.0
Interpretability
Scree plot
Parallel analysis
Rotation of Factors
Graphical Rotation
Varimax Rotation
Other Orthogonal Rotations
Oblique Rotation
Principal Factor Analysis
The Concept of Error
The Common Factor Model
Reliability
Communality
Common Factors
Specific Factors
Estimating Reliabilities
Iterating to Stable Communalities
Kaiser's Alpha Factor Analysis (the Little Jiffy)
Guttman's Image Covariance Analysis
Rao's Maximum Likelihood Factor Analysis
Multivariate Analysis of Variance (MANOVA) & Discriminant Analysis
General Purposes
Protection of Type I Error Rate for All DVs
Uncovering Composites of DVs that Maximally Discriminate
Mechanics
Find a Linear Composite of DVs that Maximizes F
The B Matrix - Sums of Square And Crossproducts Between
The W Matrix - SS & SCP Within Groups
Eigenvectors & Eigenvalues of BW-1
Wilks Lambda - |W|/|T|
Difference Between MANOVA & Discriminant Analysis
MANOVA concentrates on test of significance
Discriminant Analysis focuses on the Linear Composite
Interpretation of Results
At least One DV Differentiates the Groups
Interpretation of the Discriminant Function - Loadings
Tests Subsequent
Follow up with Univariate ANOVA
Hierarchical tests with ANCOVA (not recommended)
Profile Analysis
A MANOVA in the form of Ss/AxB
Scaling variables for profile analysis
Problems of Classification with Discriminant Analysis
Canonical Correlation
The Grandfather of Parametric Statistics
Multiple Regression - One Variable on Either Side
MANOVA - One Set is Dummy Predictors of Groups
ANOVA & r - Just Simpler Cases
Chi Square - Can be done with Canonical Correlation
Mechanics
The Matrix - XX-1*XY*YY-1*YX
Eigenvalues Equal RC2
Eigenvectors are Maximizing Linear Composites
Interpretation
A Two Sided Factor Analysis
Protection Against Type I Errors
A First Step in Investigating Relationships Among Sets
Tests Subsequent - Multiple R and Simple r
Cluster Analysis
Purposes
Discovering Subgroupings of Subjects
Numerical Taxonomy
Types of Cluster Analysis
Hierarchical Techniques
Optimization-Partitioning
Density or Mode Seeking
Clumping
Mechanics
Q-Type Correlation Matrix
A Factor Analysis on Subjects rather than Variables
Distance Matrices
Agregating Algorithms
Importance of Standardizing Measures First
Interpretation
Warning - You will always get Clusters - Are They Real?
Must Examine Clusters In Terms of Original Variables
Must Remember This is a Discriptive Technique, Not a Test