model comparison

  1. I

    Is a bayesian MCMC regression approach suitable/recommended for this complex model?

    Hi everyone. I'm trying to reanalyze the data of an experiment I did using a bayesian approach, but the complexity of the problem has me stuck. I read Richard McElreath's "Statistical Rethinking" (2nd ed.) for useful insight and I think I'm conceptually 80% of the way there, but I could use some...
  2. B

    Goodness of fit test for categorical data with non-negative real numbersca

    An experiment that I conduct has 5 outcomes: A, B, C and D. I conduct 12 trials for this experiment. I observe, for example: Outcome : Frequency A : 2 B : 3 C : 0 D : 5 E : 2 Now, I have a model that predicts the...
  3. C

    Problem with nlme() convergence in a Monte Carlo simulation

    Hello. As part of a Monte Carlo simulation, I'm programming some model comparisons on generated data. The underlying relationship in the data is a two-parameter exponential curve (y=a*e^(bx)), and among the models being compared are hyperbolic (y=a/(1+bx)), and quadratic (y=b*(x-a)^2)...
  4. C

    Can I compare regression models with same # predictors and same sample?

    Hi there, As a part of my dissertation I want to compare a focal, new, variable against other well-known predictors of my outcome, so I plan to run a hierarchical regression in SPSS with the focal variable entered on the last step. The problem is that my focal variable is highly correlated...
  5. N

    Comparing Regression Models

    Hi, I wonder if anyone can help, I want to compare two linear regression models with each other but have no idea how to do it. I have two groups (one group completed Task A than B, second group Task B than A). I split the SPSS file to analyse by group, all the variables are the same but...
  6. K

    model comparisons for a binomial distribution

    Dear all, I have a stats question that relates to a bigger piece of research, but I've simplified the bit I'm confused about... Suppose I run an experiment 10 times (M=10) where for each experiment I toss a coin 20 times (n=20), I have for each experiment the number of heads (x). From this...
  7. C

    comparing linear models to test for statistical similarities

    I am trying to describe plant growth over time using accumulated temperature (dd) as my independent variable and the plants 'growth stage' (gs) as my dependent variable. The shape of the data is sigmoid and I have three different sets of data for different geographic areas. I decided to use a...
  8. B

    model comparison, log likelihood score, P value.

    I am working on Bioinformatic analysis of genomic data. I am doing some statistical analysis and doing model comparison and have some conceptual doubts. And quite possible that it is a simple concept which I do not know, as I am not so through in statistics. I am comparing two models. One is...
  9. R

    [AMOS] No BIC value given

    I would like to test two different (and competing) CFA-models in AMOS. Both of the these used the same nine manifest variables. In one of them, there are four latent variables, in the other two. After doing some (admittedly not extremely thorough) research on model comparisons I had planned to...
  10. B

    linear regression Johnson Transformation

    If two predictor variables transformed by the Johnson Transformation (see Minitab or Johnson 1949) are used in separate linear regressions (assuming the same response variable and sample sample size of predictors in each single predictor variable model) can the R-squared output of separate...
  11. M

    Model comparison in psychophysics with multiple participants

    Hi, I have a quite general methodological question about model comparison. I ran a psychophysical experiment in which each participants performed ~500 trials of a perceptual decision task. My observation are reaction times. I want to compare several possible model to find which one explains...
  12. E

    Statistical Analysis Plan - help!

    I'm doing a summer research project on trends of anxiety and depression. Unfortunately, my preceptor has disappeared in the meantime and I'm left to fend for myself. I've done an extensive literature review, and now have to develop a Statistical Analysis Plan (SAP). While I understand that there...
  13. P

    how to calculate the significance of an R2 increase (based only on results in paper)

    Recently I have come across several articles that report OLS results of models with increasing numbers of variables. In the articles the R2 and F-statistics are reported (and, of course, t or p values for the coefficients). In these articles, I note that the R2 (or adjusted R2) doesn't...
  14. I

    Model reduction justified?

    Hi! I'm working with cox proportional hazard models in R and I'm trying to find the minimum model. I have a very simple question but I cannot find a direct answer:). These are the models and the result of the anova: anova(model1,model2) Analysis of Deviance Table Cox model: response is...