dichotomous

  1. R

    sample size for dichotomous outcome in retrospective observational study

    I really need some help here seeing if I can get this right. I seem to come up with something different every time. I am testing the hypothesis that there is no difference in the timing of removing chest tubes to the development of significant pleural effusions after surgery requiring drainage...
  2. M

    The difference of means as a fulfilled precondition for a mediation analysis

    The preconditions for a simple mediation analysis according to Hayes (2013) are statistically significant associations between X (the independent variable) and M (the mediator) as well as associations between M and Y (the dependent variable). In the case of a dichotomous independent variable...
  3. S

    Can I use fishers exact test in this situation?

    You can see in the below table that I have multiple cells that have expected counts <5 and cells with counts equal to zero + zero expected counts. As I want to analyze the relationship between my two variables, one being about attitude and the other about behavior, would fishers exact test be...
  4. R

    Point-biserial correlation when some of the test assumptions is violated

    Hi! I originally posted my question on StacExchange-CrossValidated, but no one there seems to be able to answer my question. This is the situation: I've got 15 raters who assess if there is deep invasion of a cancer type or not (dichotomous), and they can be either accurate or inaccurate...
  5. B

    Help with the level of measurement for correct/incorrect answers

    Please, help bring in some lucidity and fill in any possible gaps in my reasoning. The research assessed the participants' recall of a narrative story. One day after the presentation of the narrative, the participants were given the memory test. Their answers to some of the questions are then...
  6. A

    Okay to Sum Numerical Values of Categorical Variables?

    Hi. I have questions regarding categorical variables. Can you create a scaled variable out of several dichotomous variables? For example if I had 4 dichotomous variables, can I sum the numerical values of those variables so that the sum becomes the value of new scaled variable? If...
  7. M

    Chi Square Test, Pre Post Study, Dichotomous Variables, Different Group Sizes

    Hi Everybody, I am a medical student. I am doing a Final Year Project (FYP) and need a little help. I must admit to being a novice statistican and apologise if this question is a little dumb. My FYP is a pre-post study (i.e. pre-intervention and post-intervention). Variables in my study...
  8. T

    problem in gen. initial in winbugs

    dear all members i have a small problem in the code below. in the last step gen initial and after press on this key i cannot get on result because the program still generate these values and i cannot get on any resutls after then i must close the program because it is not work and restart it...
  9. M

    How to test difference between two unpaired groups, low sample numbers, many zeros?

    Hi, I have a problems that at the beginning seemed easy, but now it looks trickier than expected. I have two series of responses (well different series, but all of them with the same characteristics). In one, the values are almost always zeros. In the other quite often I have a response...
  10. M

    Intervention vs. Control Group for Matched Pair, dichotomous data: McNemar Test?

    I have matched-pair, pass/fail data on a reading test for 2010 and 2012. I have this for an intervention group and a control group of students. I'm trying to show that my intervention group did better than control group. I've calculated two McNemar statistics for both the intervention (sig.)...
  11. M

    SEM: combining binary & ordinal variables

    In my research I surveyed participants after they had used a website. I have 28 items which related 8 different concepts. Which means I have 8 latent variables with 3-6 observed variables each. All items are measured with 7-point likert scales. Additionally I have a binary variable of whether...
  12. H

    regression analysis

    hi. i need advise on how to do regression analysis with a discrete dependent variable and a number of dichotomous and continuous independent variables. What approach/statistical analysis should I do? Do I perform a single multiple regression model? Is there a better alternative to this...
  13. W

    Association btw. dichotomous and ordinal variables, controlling for dichotomous var.

    Hi y'all! I've got three variables: A (3-category ordinal), B (dichotomous), C (dichotomous). Any ideas on how to find a measure of association between A and B, while controlling/covarying for C? I'm currently dropping everything into the partial correlation procedure in SPSS, which I'm...