ancova

  1. B

    ANOVA/ANCOVA show same thing?

    An ANOVA showed that there was no main effect of personality trait on the D.V. (task performance), and an ANCOVA I conducted showed that personality trait did not influence the main effect seen in gender on task performance (there was a significant gender difference of personality trait, as well...
  2. D

    Ancova : A specialised model

    Hi all, I have a cross sectional data obtained from two independent groups. I have just made a logarithmic transformation of the outcome variable because it was not normally distributed. May I confirm if I can still use ANCOVA to analyze the data in this mode please: One dependent variable...
  3. C

    Using variations of ANCOVA for non-normal distributions

    My first question here, hope to be relevant to the community. Im into CS course and a total rookie on statistics, so let me know if more detail is needed and I will edit the post. I have a problem now that we want to compare sample groups and wanted to come up with a function out of it, so we...
  4. C

    Using variations of ANCOVA for non-normal distributions

    My first question here, hope to be relevant to the community. Im into CS course and a total rookie on statistics, so let me know if more detail is needed and I will edit the post. I have a problem now that we want to compare sample groups and wanted to come up with a function out of it, so we...
  5. E

    Coefficient of variation in inferential statistics

    As part of an appraisal of an article (https://ssl47.pair.com/mds/education/journalcme/journalcme_25-09.pdf) and among other questions I have been asked to "explain the rationale for the following inferential statistical tests: paired and independent samples t-tests, coefficients of variation."...
  6. M

    GENLIN with binominal distrubution

    GENMOD with binominal distrubution In our experimental design, we are assesing the effect of an intervention. our data is not normally distributed due to the reason that it is a mean count data. I would prefer ANCOVA with pre test scores as covariate if it was normally distributed. But I...
  7. R

    ANCOVA when variances are not equal?

    I am currently writing a 4th year freshwater biology report analysing data collected on the length and weight of fish from 2 sites, collected over 3 years. We need run an ANCOVA checking Weight v Length/Site(SPSS, weight=dependent, site=factor, length=covariante). After checking...
  8. R

    fixed effect with ancova

    Hi all, I need calculate fixed effect with ancova analysis (spss or genstat). My experiment was on fishes growth with differents diets (8): 15 fishes in each tank (each diet in triplicated, 3 tanks for each diet, total tanks:24). I need calculate p value for fixed effect: tanks and diets...
  9. S

    Homogeneity of regression slopes

    If assumption of homogeneity of regression slopes broken in ANCOVA analysis, what to do? Can I use linear regression instead? Thanks
  10. M

    HOW do I insert a baseline covariate in repeated GLM?

    Am I doing something wrong? Using repeated GLM. Two groups, experiment and control. Dependent is a score on a scale. Data (the same score on the scale) are collected pre intervention and two post-tests. I am going to use the pre-test scores as a covariate to correct for possible...
  11. K

    Covariance structure question for mixed model repeated measures ANCOVA

    I'm working on a mixed model repeated measures ANCOVA and am working on identifying the covariance structure for my model. I am interested in modeling 2 of my variables as repeated measures, and am wondering if this is even possible. I'm working in SAS, and keep getting error messages telling me...