t-test

  1. N

    Application Specific: Strange behaviour of students T-test compared to std.dev plots

    Hello all, ******************************************************************** SEE THE FITH POST OF THIS THREAD TO GET A BETTER IDEA OF THE ISSUE ******************************************************************** I am comparing three datasets of length 7201 datapoints each (on images this is...
  2. 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...
  3. B

    Which test to perform? T-test or ANOVA?

    Hi, My hypothesis is worry will be significantly higher in individuals with high body dissatisfaction and self esteem lower compared to a healthy control group. I'm comparing two groups (control and clinical) so I thought t-test. But I'm also comparing two means (worry, self-esteem...
  4. Z

    Please help! We've got lost in the wild jungle of T-TEST!

    Hello, We have been working on an assignment of t-test analysis, but the data we got look very puzzling and perplexing. I really need your help! The task is to analyze a set of t-tests from a hypothetical study (1 paired t-test and 3 independent t-tests). But, the problem is... the set...
  5. B

    [Marine Biology] ANOVA (with unequal variances) statistical test?

    I have a pretty complicated data set that I don't know where to start. We sampled intertidal snails through an observation method, at two locations. We measured the shell sizes of snails found IN crevices and OUT of crevices. I originally thought to group all of the IN snail and OUT snail...
  6. gianmarco

    regular t-test VS Welch's t: white paper

    Hi, I came accross this interesting white paper. Here is the link. It deals with the topic of the assumptions of traditional t-test and of its comparison with the Welch's t. The pros and cons of each are evaluated. I found it in the site of Minitab program. Nonetheless, I think it can prove...
  7. D

    T-Test for A/B/C split population

    Hi, I am wondering if my assumption is right on the following procedure t-test. Basically, I have three different creatives running at the same time and I would like to see if the difference between response rate of the 3 creatives are statistically significant. Typically, when I have only 2...
  8. T

    Help to reply to reviewers. Is student t-test = anova for two groups?

    Hi, I have received the reviews for a paper I wrote where I have a rather complex design. But for my question I explain only the relevant bit. In a between participants design, I present participants with one of two scenarios (hedonic vs. utilitarian goal). As the classification was not...
  9. 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...
  10. L

    Paired t-test using averages

    Hi, I would really appreciate if you could help me with my research design for my thesis. I am investigating a group of companies in terms of % of female employees compared to the respective industry average. The problem is that the companies are from different industries, and of course...
  11. J

    Gene expression analysis - FDR and p-values

    Hi, I'm using Affymetrix microarrays to check if there exist some differences in the gene expression of two group of animals that have been differently treated. I'm using a t-test with permutations (as my groups only have three animals and I read that it is better to use permutation if you...
  12. M

    Interpreting a paired t-test for price means

    Hey everyone, I am new to this, but I would be extremly thankful, if someone could help me with this. I research the topic of rate parity for hotels in Germany, which involves comparing rate means for different distribution channels. I have performed a paired t-test for the "phone rate...
  13. B

    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%...
  14. A

    One sample t-test

    Hi, This is probably an embarrassingly easy problem but I've looked all over the place and I can't seem to find the answer, or at least I don't know the correct search terms. I have the maximum daily temperature for a particular location going back 30+ years. From this data I've calculated...
  15. N

    T-test puzzlement

    I've been pondering on this for some time and I guess i'm confused because there are so many stats tests out there. Basically my aim is to figure out if there is any statistical relevance between years of English learnt and correct answers on an English test. I have put years into months...
  16. C

    Help with t test interpretation

    Hi, I am hoping someone can help explain the following. In comparing the means of two distribution, m1 and m2, let us say m1 = 10 and m2 = 5 I am trying to interpret one-tailed and two-tailed tests. If the area to the right of critical t value (m1 - m2)/SD is 5%, then in a two-tailed...
  17. J

    T-Test with 2 samples with large absolute difference

    What do you do when the test and control volumes are significant different? Would you adjust (normalize) the differences only, or both P1 (period1) and P2 (Period2)? When you normalize, would you mix both the test and control, or would you normalize them separately? I am adding some numbers...
  18. 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...
  19. G

    Analysis of respiration

    I am trying to analyze egg respiration data. I have 7 eggs that were measured over a 10 day period. I have data from 45 minute runs, that I have taken 5 minute averages of giving me 9 data points per day per egg. I need to analyze the change in gas over the course of the run. Then I need to 1)...
  20. P

    Transforming two non-normal sets of data for 2 sample t-test?

    Hey all, Ok so I'm trying to compare the means of two sets of data using a 2-sample t-test. Unfortunately, both sets of data are non-normal. It appears box-cox or Johnson transforms will work, but my question is, wouldn't I need to transform both sets of data using the same transform...