significance

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    Selecting Variables for Multiple Regression (Univariate Significance Levels)

    Hi All! I really hope someone can answer my question. I am building multiple linear regressions and I am testing salient variables one by one at the univariate level to determine whether I should include them. However, what is the current acceptable limits of p values to include/exclude...
  2. C

    T test vs. Chi Sq

    Is an unpaired t-test the same as a chi sq test with respect to the resulting p-value if I'm using categorical data (0s and 1s)? Thanks.
  3. C

    3 Arm Study: Categorical Data needs a P-Value!

    Hi, I conducted a 3 arm study and now I am trying to find signficance/lack of signififance. Some data I gathered, such as age was easy to calculate via ANOVA tests. But now I have smoe categorical data that neds to be analyzed. For example, I examined the quality of my procedure and it was...
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    Computing confidence for multivariant tests

    We'd like to compute an overall confidence value for a test with multiple variants (sometimes with no control). We've used Student's and Welch's T-Test for A/B tests in the past, but these multi-way tests don't seem to fit the bill. What sort of formula should we be using to compute...
  5. C

    3 columns of categorical data - what test to use for significance?

    Hi I did surveys on pre-teens, teens, 20s (3 "columns") and need to find signfifiance (p-value). What test do I use? I keep trying Chi square on graphpad prism 5, but I keep getting the message Analysis of Contingency Table: Overview Chi-square calculations are only valid when all expected...
  6. A

    can not figure out simple question, please help

    hi everyone! I have the following question: while running univariate GLM, I have encountered the situation when mean differences between groups are the same, but in one test they reach statistical significance, whereas in other not. Probably the reason is that in one case std. deviations are...
  7. C

    Not Significant Coefficients

    I've run a logit regression to estimate the probability of attending high school. I've done this for many years. The thing is that some coefficients resulted to be not significant in some years and significant in some others. So my questions are: 1- The fact that a coefficient is not...
  8. R

    Overlapping Samples T-test

    Hi, Could someone please tell me how to do an overlapping samples t-test? In my survey, respondents rate (0 to 10) any of 10 options that they're familiar with. So I want to compare the average ratings (significant difference or not) of the options to each other, keeping in mind that in each...
  9. L

    Co-efficient of variation to eliminate frequency bias in vector

    0 down vote favorite I need to determine the significance of a certain variable (i.e. cue) that co-occurs with an element of a particular class. I am working with vectors that are similar to this: 346,0,0,0,123,0,5,1,134,0,0,83,1,dog 478,0,1,0,0,90,293,38,0,0,56,0,0,car In...
  10. M

    Dice's similarity coefficient (aka nei and li). significance...

    I've been struggling with the Dice coefficient for days now. I understand that the closer to 1 the cases are the more similar they are but is there some way of obtaining a p value for this to show some level of how significant this similarity is to one another? i can't seem to find anything...
  11. A

    Comparing Survey Results

    I just recently administered two surveys testing the effectiveness of a product. Each survey consisted of the same 3 questions and were answered on a 10-point Likert scale. Survey A was given to 20 participants before the product was administered and the answers to the questions were as...
  12. W

    Significance testing on share of spend

    Hi all, can someone point me in the right direction for how i would work out stat sig of share of spend? eg - 5 companies in market, ask ppl how much you spend with each for say phone bill. This will then give total spend for each of the companies, and total market spend, therefore can...
  13. K

    Using multiple P-values

    I have a number of p-values from permutation tests I've done on my data. One p-value for each recording. Can I compile these values to test for overall significance?
  14. L

    Testing the significance of differences between means of two samples.

    Hi, I am currently working on an event study that compares domestic and cross border mergers and acquisitions. I have gathered two samples one for domestic (3050) and one for cross border transactions (2040). Both of the samples were selected using same criteria with respect to announcement...
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    superior returns market portfolio

    I have the returns and standard deviations of 10 portfolios and i want to know if they significantly beat the market portfolio. the portfolios annual retuns standar deviation 1 20% 5% 2 15% 10% 3 25% 15% 4 14%...
  16. M

    Significance of moderation

    Hi there, I have 3 moderators. Following regression analysis only one moderator is significant. However, the R square change is just 0.02. I have decided not to include it in my model because of the following reason: "The significance of the model and the increase in R square was expected...
  17. L

    Testing a learning curve

    Hi all, Suppose someone kicks a football at a goal. However, I want to test to see whether or not practice improves technique - whether there is a "learning curve". I get 100 people to kick footballs at a goal 50 times each. I want to test whether there really is a learning curve, or...
  18. H

    Significance Level Help

    The Suzuka Automotive Company claims that its Accent model gets the best gas mileage, in terms of miles per gallon (mpg), of any car on the market. More specifically, it contends that the Accent gets better mileage than the Hondo Slavic CPX model. To test this claim, Suzuka retains an...
  19. A

    Bonferroni correction in GLMs

    I'm running a series of General Linear Models, attempting to explain factor x with 6 other factors; individually, all 2-way and all 3-way. Due to the large number of significances which I am trying to find is it neccessary to apply a Bonferroni correction to effectively decrease the p-value...
  20. L

    Significant regression coefficient vs. significant overall model

    Hi everyone, I have rather a simple question but for some reason have not been able to find a clear answer. My apologies if I have missed a previous answer in my searching. Here is my question: What does it mean if you have a highly significant regression coefficient for a predictor, but...