group differences

  1. A

    How do I compare between-test changes in mean across groups with different starting means

    I have 10 groups that took a test at two different points in time. Each group had a different starting mean. i think my null hypothesis is that all groups improved the same amount relative to their first test mean. I am confused about how to actually compare the differences in means across the...
  2. R

    Which statistical tests should be performed?

    Hi, I did experiment to compare the effect
  3. W

    Separating 5 item construct with scale 1-7 in three groups

    Hi there! I would like to separate my 5 item questionnaire construct (with a scale from 1 to 7) in three groups (1 (low) - 2 (middle) - 3 (high)) to investigate group differences. Can anybody help me and tell me how I could do that? Does somebody remember a paper where somebody has done this...
  4. J

    Let me know a better analysis method?

    I have two IVs; "collection method" (online and classroom) and "culture" (A and B), one continuous variable ("Age") and 8 DVs (well-being variables and self-construal variables). I wanted to see if the two cultures were different in those DVs controlling for "collection method" and "Age". My...
  5. C

    associations and correlation VS Group differences

    Hello to all Talk Stats members! I would really appreciate your help on an issue that's really troubling me... In a previous post of mine I talked about the following likert type question I have in my questionnaire; "How would you evaluate new technologies in your life?" (1: entirely negative...
  6. B

    Proper analysis for group differences in proportion scores

    Hello all, I am running analyses looking at group differences in the proportion of time kids were distressed in a task. I have a task that has been broken up in to 10s time slices and kids receive a score of 1 in each slice they evince distress. To create my outcome variable, I am dividing...
  7. F

    Linear Regression with effect size changes of categorical variables with continuous

    I have three categorical variables (disked, herbicide, Lands) each is binomial (0,1). For example, within disked there is a group in which it does not occur (0) and where it did occur (1). I am performing a forward stepwise-approach in which I evaluate each categorical variables in the order...
  8. U

    Different results by adding a third group?

    Hi, In my study I first only compared two different groups (1 and 2) on a number of variables. For one variable in particular, these groups were significantly different from each other (found that on t-test and ANOVA). Now I added a third group to the sample. In each of the groups N=21...
  9. F

    Find whether one mean is very different from all others in multiple measurements

    I have many data frames like the one reproduced below in R. I am trying to find cases where one group only is very different from the other groups (I have a variable number of groups for the different data frames). I have tried with ANOVA, but this test only tells me if the group means are...
  10. S

    Meta-analysis: How should one handle non-significant studies containing no raw data?

    Let's say that I'm conducting a meta-analysis, looking at the performance of group A and group B with respect to a certain construct. Now, some of the studies that I'll come across will report that no statistical differences could be found between the two groups but no exact test statistics...