1. L

    Unbiased estimate of cross-product for unbiased vector

    Let g be an unbiased estimate of a vector G. Can g be used to find an unbiased estimate of the cross product GG′ (where G' is the transpose of G)? I'm stuck because naively using gg′ is a biased estimator, with the (upwards) bias depending on the noise in g.
  2. B

    Interaction term in multiple regression with categorical variables

    Hello everybody, I have question concerning categorical variables and multiple regression: My Scenario: I have two independent categorical variables (X1 and X2) coded by dummy variable 0,1, and 2 (i.e. genetic data). If I want to calculate the interaction term, can I also use the product...