# contrast coefficients

1. ### Defining Contrast Matrix

In the book Applied Longitudinal Analysis, 2nd Edition there is an example in the chapter "Marginal Models: Generalized Estimating Equations (GEE)" in "Muscatine Coronary Risk Factor Study" sub-section. I am illustrating it below : Let Y_{ij}=1if the i^{\text{th}} child is classified as obese...
2. ### Confused with Contrasts

Hello, during the last days, I tried to understand the use of contrasts, but the more I read, the more I am confused. As far as I understand, a contrast represents a specific hypothesis regarding the relationship between means of K levels of a factor variable. This is done via...
3. ### Contrast coding for a 2x2 ANOVA in SPSS - Lmatrix error

Hello all, I'm interested in testing my data for a particular contrast. I have two independent variables each manipulated at two levels between subjects resulting in a 2x2 design. The first independent variable (MT) is coded as either 0, 1. The second independent variable (PA) is also coded as...
4. ### ANOVA contrast coding for 4 groups.

Hello, I have four groups 1, 2, 3, and 4, and I'm trying to compare the average of 1 and 2 vs. group 3 and group 4 (note not the average of group 3 and 4). Can someone help me with what my contrast coefficients should be? Thanks in advance!
5. ### planned comparisons - contrast coefficients - trends

Hello! I’m going to conduct planned comparisons with contrast analysis in ANOVA. In particular I am interested in trend analysis. The problem is that I have n=11 groups and I suppose that my trend is quadratic. What are the contrast coefficients for 11 groups? Is there any universal...