1. S

    orthogonal lines

    Hi! I'm trying to learn PCA and am struggling with the concept of orthogonal lines, and why they need to be orthogonal. Is it correct to say that if two lines are orthogonal to each other then they are uncorrelated, independent or both? Thanks!
  2. M

    Automatic addition of contrasts

    Hi, if I define contrasts for a factor variable with n levels, e.g. contrasts(x) <- c(-2,1,1) and I subsequently display these contrasts via contrasts(x) I obtain - beside the self-defined contrasts- (n-1) additional contrasts (second row): [,1] [,2] -2...
  3. G

    Conjoint Analysis, Syntax, Cards

    Dear all, I'm setting up a customer research using a conjoint analysis (SPSS) and have a few questions. 1. Do I need to set up the syntax file before collecting answers or can I do that afterwards? 2. Is there a way to change the orthogonal design (in SPSS) after I've run it? Or do I...
  4. C

    ANOVA - Orthogonal Planned Comparisons

    We've been given this question on a sample exam paper. An experimenter is exploring the effects of two appetite suppressants in rats. Suppressant A induces mild nausea, while Suppressant B suppresses the sensation of hunger. Half the subjects receive a low dose of one suppressant, and half...