paired t-test

  1. StrangeCharm

    Which approach to evaluate small spatial variations in temperature?

    I am evaluating whether utility-scale solar energy plants affect the surrounding climate (initially temperature). An effect has been found in one paper using the approach described below/attached but when repeating this approach I find no effect for the same site. I want to be sure that there...
  2. M

    Lilliefors test for paired series + Bonferroni correction

    Hi all, I got two series where I want to find out if they differ. The two series are paired meaning they are values for the same subjects. N = 21 After: 0.87348565, 0.88276705, 0.89083918, 0.89520159, 0.89519151, 0.90286579, 0.90586482, 0.90750014, 0.90978787, 0.91008748, 0.91230162...
  3. P

    Testing mean difference on group means, multiple independent groups/sites

    Hello Talk Stats group, I am trying to find out what statistical tests to run on a set of aggregate data (no individual data) on 3 different groups. My variables are summarized below (but I aam attaching a random example to make it more clear): Group 1 in site 1: Mean value (blood sugar)...
  4. C

    Paired T Test ???

    Hi I am trying to work out which statistical test to use to determine whether there is a relationship between visual acuity (how small letters on a letter chart are) and contrast (how dark the letters are). I have used one sample of participants and tested both visual acuity and contrast on...
  5. L

    [SPSS - wilcoxon/paired t test] - not normally distributed data

    Hello! I ran an analysis of my data of research into a repeated measures design and found the difference of both conditions to be not normally distributed. When exlcuding data to make it normally distributed and thus use parametric tests, can we only exclude data that exceeds the limit of...
  6. B

    Repeated t-tests or ANOVA for discerning difference between two treatments

    Hello, I am helping my sister with some statistics in her master's dissertation in behavorial/social sciences. I have studied a couple of courses on statistics/probability, but my proficiency could certainly be better. I have this book "An Introduction to Mathematical Statistics and it's...
  7. L

    Paired T-Test and/or repeated measures ANOVA/mixed ANOVA -please help!

    Hey everyone, I've been trying to confirm this for a while but I haven't been able to find a conclusive answer. I'm guessing the answer is pretty simple but I'm a bit rusty and I've looked over it so many times that I'm now a little bit saturated. Basically I am doing a project on bladder...
  8. L

    a question about statistic approach to use

    I moved this thread to another place and please delete this thread. Thank you.
  9. O

    Comparing affected sides instead of just left and right.

    Hi. I'm relatively new to statistics and SPSS. I've been testing the shoulder strength of 200 shoulder patients divided into two groups. I've been testing both of their shoulders, so I could have a reference value. I would like to compare the affected shoulder of group 1 to the...
  10. J

    How to test dependent means with unequal sample size? Weighted Paired T-test?

    Does a Weighted Paired T-test exist? I am comparing the percent of a population that are juvenile between 'Autumn' and 'Spring' at many sites. The Sample size (n) is variable among the sites and between the seasons. Sample data: Site___Fall %__n_____Spring %__n...
  11. A

    One-way anova or paired t-test on intervention study? OR BOTH?

    Hi all. I'm planning a study where I get 3 separate groups of people, make them all do a satisfaction questionnaire, then give each group one different intervention (i.e. 3 different interventions total) and then get everyone to do the same satisfaction questionnaire again after the...
  12. C

    Age and DNA methylation data: HELP NEEDED

    I have data on patient Age as well as change in % DNA methylation levels for promotor regions. I seek to understand the impact of Age on the % change in DNA methylation levels. What is the best way to do this? Paired t-test of Age vs % change in DNA methylation data yields ridiculously high...
  13. C

    Paired bootstrapping

    Hey everyone! Absolute newbie to R, would appreciate help with a question I have been struggling with. Let's say I want to test the efficacy of a medicine in reducing blood pressure. So I have a paired sample . Three vectors are created in r. Before <-c(129,135,145,89,70) and after...
  14. N

    paired t-test or repeated measurments ANOVA

    Hello Given a group where you run 2 models to obtain a parameter, and the goal is to compare both parameters. But not all individuals tested in one group are tested in another, so there is some variance. If using a paired t-test you execute an F-test to see if the variance is acceptable...
  15. G

    Inference from sample splits when coefficients are not significant (Panel Data)

    Hi, I’m new to this forum and have got a little stata problem. Status Quo: I use panel data and a fixed effects model. My independent variable is negative and statistically significant over the whole sample. To test a theory I split the sample in two halves (A+B). Theory predicts...
  16. 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...
  17. N

    Variance and sample error in paired sampling

    Hi everyone, I have a question regarding variance and sample error in paired sampling. If I want to see how a parameter changes over time i take sample "A", then re-sample "A2" at a later time. In my case, the sampling is destructive, so sample A cannot be re-taken at a later time. I will...
  18. B

    [Students T Test] - paired or unpaired unequal variance?

    Hi, i have a question as to whether a paired test in this instance is appropriate. Scenario: an experimenter is testing a new treatment to see if it increases a certain property of a substance. The experimenter chooses 4 groups of the substance and takes 3 sample from each group and tests for...
  19. A

    Pre-Test/Post-Test With Multiple Tests Running

    Very new to this statistics thing and could use some help deciding how to run the data for this. 60 participants (30 control/30 intervention). Each person is being given 5 different likert-scale assessments, oral cortisol swabs, blood pressure pre-test and post-test. I'm studying the effects of...
  20. A

    Quantifying trends and patterns, which test to use?

    Attached is an image of some graphs showing the relationship between a factor which varies year on year, compared to various other factors. With many of the factors it is clear to see that there is a relation between them, however I'm unsure as to how best to show this quantitatively! Many...