beta regression

  1. N

    z-test or beta regression for assessing differences between groups of averaged proportions?

    If I'd like to test the hypothesis that there is no difference in mean seagrass cover between two months, over all years, what test/analysis is best to use? My thoughts move to a z-test because I'm testing differences between two samples and the sample size is >30. On the other-hand I've...
  2. J

    Bias in Zero-One Inflated Beta Regression?

    We have recently been trying to use the zero-one inflated beta regression macros that were published as part of SAS Global Forum 2012 (see... they have been very helpful in more accurately modelling the Loss Given Default (LGD)...
  3. S

    Mixed model Beta distribution fit diagnostics

    Hello, I have a split-plot design and I want to test the effect of 2 factors on the disease incidence (continuous proportion). I am using Beta dist. which is appropriate for these data (bounded within 0-1). The fit statistics look OK (Pearson Chi-square/DF close to 1) Fit Statistics for...
  4. hlsmith

    Beta Regression Resources?

    Does anyone have some good resources for Beta Regression related to all of its parts: -assumptions -diagnostic (residuals) -interpretation of independent variables (continuous and categorical) -etc. _____________________________________________________ I am going to get a dataset...
  5. M

    Non-proportion percentage as a response

    Moderator note: This thread was split from a previous thread as it didn't directly address the question in the previous thread and deserves its own space Hi everybody, I know it is a bit old topic but I hope someone can give me advice. I have a similar situation (ANOVA with percentages) but...
  6. T

    Beta NO Intercept purpose

    Hey guys, What would a Beta with NO intercept tell me about a time series model?
  7. Amanda_UK

    Beta-Regression and AIC (model selection)

    Hello, dear fellow R users, I am using beta regression because I am trying to predict percentages (response and dropout rates) of surveys. My aim is now to come up with a final model (I have many different variables and want to reduce them to a final model). I wanted to do that by using...