anova

  1. H

    Identifying correct statistical test for comparison of two groups related to time

    Hi, I'm conducting research into woodlice grouping behaviour. I have tested three conditions that are full darkness, full light, and a half-dark, half-light group with each having a total of three replicates. For the full darkness and full light conditions, I measured the frequency of...
  2. O

    Study design

    If I’m doing an fmri experiment with two between-subject factors (two treatment groups) and 3 within subjects groups (baseline, post-treatment, follow-up. Which design is better a 2 x 3 ANOVA flexible factorial design, or a two way mixed effect repeated measure? Thanks!
  3. R

    ANOVA for Sampling bias detection

    I hope that this is the right place for such a question. What test to use to detect if the selected sample has a bias or not? We have a protein that naturally binds with certain short known DNA sequences (let's say 5 nucleotides each). what I want to show, is that from all possible...
  4. B

    F test significant but simple contrasts not

    Hi All, I have conducted a repeated measures ANOVA, examining one of my dependent variables over 5 time points. I have a significant main effect from my F test but not when i am examining my simple contrasts (see images below). Could anyone offer any advice on why this is and what should be...
  5. B

    Post-hoc pairwise or simple contrast ANOVA

    Hi All, I am examining a dependent variable over 5-time points but what I am really interested in is how the dependent variable differs in comparison to the first time-point (baseline). Firstly, which ANOVA is more appropriate, a repeated measures ANOVA with post-hoc analyses or a simple...
  6. R

    Comparing Groups - Are my stats tests biased?

    Hi, I am testing for statistical significance between lipid (oil) yield of two separate algal species split into four groups total. Each species has been split into two treatment groups, one with fewer nutrients and one with more. Therefore I have four groups to test statistical differences...
  7. L

    How to convert my output into a suitable table for ANOVA or Kruskwallis testing on SPSS?

    Hi guys, Let's say I have asked an individual to classify images according to 3 fruits that he sees : apple, banana and kiwi. Then, I want to assess whether there are significant differences between the frequencies of each classified fruit (there are more instances, this is just an example). I...
  8. Z

    2*2 repeated measures ANOVA with an unbalanced number of observations

    Hi everyone, sorry for this very basic question. I've trawled through previous pages and cannot quite find a case that corresponds to our situation. 320 individuals rated two types of films. The rating was provided on a 1-11 scale.There are many films of each type. In short the DV is a...
  9. K

    Why three-way ANOVA doesn't match with multiple comparisons?

    Hi, I'm running a three-way ANOVA on a multifactorial dataset and it says all three (Device, HRT, Dose) variable has a significant influence on the data. However, when I run multiple comparisons, groupings and significance appear only based on one of the variables (Dose). Why is that and which...
  10. B

    Grade data - difference among graders

    Hi, I have 6 groups of grade data, scored by 6 different graders. I want to know if there are statistically significant differences between graders. Each score was earned by a different student. There were 72 students in all. I ran an ANOVA, but am not sure if that is the right approach...
  11. H

    Are transformations appropriate for my dataset?

    Hi all, I have a question about transforming data before running a 4-way ANOVA: I want to run a four-way ANOVA on my data set (factors: BWWW). However, due to the nature of one of the between-factors, a ceiling effect is reached in most of these data subsets, but not all. This means that the...
  12. P

    Confused about what type of ANOVA is required

    I'm doing a study for university which involves a series of participants (about 150), undertaking a study with 3 conditions and a control condition. The participants are all of different ages and are both male and female (though not an equal number of each) and all participants see all...
  13. A

    Within-Subjects ANOVA with low sample

    Hello, I have some data that I want to analyse. It is 2x2 within-subjects design. My DV is continuous and the two factors have 2 categorical levels. But I only have 8 subjects, so I am unsure about how to proceed. Is it correct that there is no reasonable alternative to just using an ANOVA? If...
  14. P

    2-sample t-test shows no equal means, can I still compare capabilty analysis and Ppk's?

    I want to compare two categorical situations (old vs. new part in a machine) with the continuous CTQ, the y-variable. In order to compare the 2 situations, I found the proper distribution and compared the two Ppk values. I saw a significant difference in performance (the new part was +-3 times...
  15. J

    degrees of freedom with a mixed anova design

    Hello - I am trying to figure out why my degrees of freedom are decimals rather than being whole numbers. I am running the mixed anova in R and the assumptions have all been met. The sample sizes of the two groups are unequal. Would this be an explanation? Or could it be that there is a...
  16. P

    Manova, Hotelling's T^2, t-test or Anova?

    Hello, For my final thesis, a few questions arose during the pre-registration process and I would be very happy to receive answers. I will conduct an experiment with three groups (1, 2, 3) and 3 dependent variables (a, b, c) to find answers to the following 2 hypotheses: H1: M(2) > M(1) -...
  17. L

    two way ANOVA?

    Dear all, I'm new to statistical analyses and currently using SPSS, and my question is: is the two-way ANOVA the right approach for my case? Because while analysing the data it was noticed that will only have one position, meaning that group would be repeated many 3 times more than single...
  18. B

    ANOVA with missing case

    Hi All, I was wondering if anyone could shed some light on a current situation I have encountered. I have a study set-up with 13 participants that I am examining over 5 time-points, hence, I intend to conduct a one-way ANOVA. However, on one of the time-points, a participant was unable to...
  19. M

    Measuring categorical (race) and two continuous varibles

    I need your help to identify which test I have to implement for measuring the correlation of one categorical and two continuous variables. In my study I have two constructs: 1- information consumption from credible sources (CS)--4 items(ie., information consumption from CDC website) 2-...
  20. S

    Testing two independent variables (categorical and interval) and interactive effects on continuous data?

    Hi, I'm not sure if there is an actual statistical test for this, but I want to see how Side (Left or Right, categorical) and Depth (Interval, fixed at every 250, but I don't have data for all depths) affect a continuous parameter I have. I initially tried a multiple linear regression, I am...