degrees of freedom

  1. S

    meta-analysis vs. random effect combined analysis

    I have data from 200 similar studies, all measuring the same effect of a continuous independent variable on the same continuous response. I say similar because the designs are different (split plot vs. rcbd) and the levels of the independent variable is not the same across all studies. I have...
  2. B

    Model conception

    Hello! I have a basic stats question: I want to model a phenomenon, and estimate parameters. How many observations would I need, to be as accurate as possible? I think it might have something to do with the degrees of freedom, but I am not exactly sure how to use this information. From the...
  3. A

    Different degrees of freedom when reporting multiple T-tests

    Please refer to Table attached. This study compares those without a phobic disorder (n=83) with those with a phobic disorder (n=16) on Temperament scores. What I am confused about, is the reporting of the degrees of freedom: shouldn't the degrees of freedom all be the same number (i.e., n -...
  4. S

    Increasing variables decreases DFs?

    I'm sorry if this is a total noob question, but I cannot figure it out. When I'm adding variables into my regression into STATA, the degrees of freedom (and observations) decreases significantly. In particular, adding one variable decreases them by about 1,000. I am only looking at the same 6...
  5. S

    Help needed for upcoming exam: Chi square

    Okay...I have calculated my chi square with an answer of 8.33. No alpha is specified (so Im assuming it would be stated as 0.05). Degrees of freedom is 1 Question 1: How do I know what the p value is from this information question 2: what does 8.33 mean? does this correspond to a p value...
  6. R

    Degrees of freedom for Chi2 normality test

    I have found mixed information in regard to the number of degrees of freedom used to evaluate the chi2 statistics derived to check the normality of a given data set. In one case I found that df = Nbins - 3 and in other cases I have found df = Nbins-1 The idea of this test is to divide the...
  7. R

    Post hoc test for Trend analysis and other

    Hi all, I'm new to trend analysis and would like to get some advice. My study is about treatment intervention on learning. Between-subject variable is treatment group (treatment1, treatment2, no treatment) and within-subject variable is time (time1, time2, time3). My dependent variable is...
  8. W

    perMANOVA using Adonis in Program R (DF and Multiple Comparisions)

    Hello there, I’ve been having some concerns with the degrees of freedom R has been giving me from PERMANOVA (adonis), and I was hoping someone could shed some light on this. I have been looking over my R books and manuals, general statistics books for calculating DF, and surfed the stats...
  9. C

    Output format using GENLINMIXED in SPSS

    Hello, I'm new to using the Generalized Linear Mixed Model function (GENLINMIXED) after some experience with the Linear Mixed Model function (MIXED). The GLMM output uses an unfamiliar format returning an interactive presentation rather than straightforward tables as they do in LMM. After...
  10. M

    degrees of freedom for two-way repeated-measures ANOVA

    I had a related topic over on the R forum involving my lmer model, but now I'm more concerned with the degrees of freedom, which I thought was a more general question that would be more appropriate here. My study had two crossed within-subjects factors. 44 subjects used an interface for 6...
  11. M

    within-subjects design using lmer and random effect

    I conducted a study with two crossed within-subjects factors. 44 subjects used a single interface for 6 rounds. Each round contained 3 trials, each with a different memory task condition (3 conditions in random order). So this makes a 3x6 design. There are generally large individual differences...
  12. J

    Degrees of freedom for a moving average?

    Can someone please help me to determine the correct number of degrees of freedom used when calculating a moving average? For example, with annual time series data values from 1900-2000 I would like to correlate both annual and 5-yr moving average values to another independent data set...
  13. M

    AMOS Bootstrapping - Mean Chi Square/df?

    Hi, I am working on a project modelling a variety of psychological outcomes for AIDS-affected youth in South Africa. Inevitably, some of our variables are not normally distributed, so we have used the bootstrapping procedure available in AMOS to estimate paremeters in the model...
  14. L

    Degrees of Freedom for ANOVA with Random and Fixed Effect

    Hi, I have completed a 2x2 experiment testing the effect of level of information (high vs. low) by spokesperson gender (male female). For each condition (e.g. high info-male) there are four replications. As much as I understand, it is recommended that replications are treated as random...
  15. A

    Is a Chi Square an appropriate test for this situation?

    Hello : ) I've been struggling for a while with this now; any help will be very much appreciated. I'm working on a project, which in part looks at whether the same whales are seen together more often than would be expected by random chance. Looking through my text book I thought the Chi...
  16. checolt

    Should degrees of freedom be explained?

    I've always been dissatisfied with the "explanations" of degrees of freedom presented in statistics courses. These explanations either rely on mystery ("the number of scores that are free to vary") or magic (N-dimensional geometry). It turns out there is an explanation that non-math majors can...
  17. drewmac

    DF and fishers vs. pearson's

    Hallo everyone I'm having a mental block today, and having trouble getting my df value. So, here's a summary of my data to help: 32 participants face-to-face 18 participants online 40 questions; binomial correct/incorrect answers I'm comparing the accuracy rates of the face-to-face...
  18. J

    degrees of freedom after adding means?

    I have what I suspect is a simple question, but I couldn't apply Wiki's simple explanation and I couldn't understand the more complicated matrix based on. I am trying to determine if the statistic in group A is larger than that of both B and C combined. I added the means and variances of...