JohnnyB
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 JohnnyB
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Hi Eris, In the Rcode on line 243, there is the calculation of cohen's d: d< mean(c1c2) / sd(c1c2) So the mean of the difference scores of the two groups, divided by the standard deviation of the difference scores. It would indeed be good to …

Hi Da5Ax, When you untick this option, you basically conduct a series of paired samples ttests between the different contrast groups. These ttests each use a separate error variance, rather than a single error variance (which is the default). Note…

Hi AaronAng, I see that not all standard deviations are the same in your descriptives table, which will lead to different pooled standard deviations and standard errors, and therefore t and p values. Kind regards Johnny

Hi Alessio, Thanks for pointing this out. We should be more informative about this. The best avenue for such a feature request would be our GitHub page, so that we can add it to our todolist and assign it to the relevant people. As I understand rig…

Hi MarieLaure, Comparison 3 compares the conditions IIT and IT, where the estimate column refers to the estimated marginal mean difference of mean(IT)  mean(IIT) (since IIT has a minus in the contrasts). This estimate is positive, which indicates…

Hi Iris, In the RM ANOVA, this depends on which setting is used for the "assume equal variances" option. By default this is turned on, and JASP uses the default behavior of the R package that is under the hood in JASP  emmeans. If the opt…

Hi Zhenzhen, To give a more precise answer, I would need some more information on your setup: how many factors did you include, are these factors measured between or within subjects, and which specific models are being compared in your Bayes factor?…

Hi Alg, The name random factors in the Bayesian ANOVA is a bit misleading I'm afraid, since what it means in this context is that the factor is automatically included in the null model and has a wider prior distribution by default. If you want to fi…

Hi Emma, To add to EJ, your data would be suited for either a RM ANOVA or mixed model. For the RM ANOVA, you would take imageType and frequency as the repeated factors. Your data would need to be in the wide format, where each row in your data set l…

Hi Chris, If you want, you can also send the data to j<dot>b<dot>vandoorn<at>uva<dot>nl, that way I could take a closer look at it. From the plots you posted it seems that reliable cue + most truth and weak cue + most lie yi…

Hi Kindred, From the code from the twosample ttests in JASP, I see the following: num < (ns[1]  1) * sds[1]^2 + (ns[2]  1) * sds[2]^2 sdPooled < sqrt(num / (ns[1] + ns[2]  2)) if (test == "Welch") # Use different…

Hi Manuel Yes, that is correct!

Hi Manuel, To add to what EJ said, the simple effects analysis is simply a conditional anova, with some correction for multiple comparisons (using the total sum of squares and degrees of freedom to compute the conditional F statistic). Unfortunate…

Hi Noamwe, That is an excellent suggestion, I will look into adding this to the next version of JASP. Thank you @MSB, I will use these resources for the implementation! Cheers, Johnny

Hi Chris, All JASP modules are now in separate github modules  you can see the ANOVA repository here. The R code for the simple main effects is on line 1573. The computation is a combination of emmeans and some manual computations for correcting th…

Hi tourette95, As a result of the approach used to enable Bayesian inference for the MannWhitney test, we obtain a posterior distribution for the standardized effect size cohen's d, but on the latent level. You can read more about this in the corre…

Just to confirm that EJ is right on this one =)

Hi Pchs0114, Pooling is generally done to create a slightly more powerful test. The "price" you pay for this is that you need to satisfy the assumption of equal variances across the levels of your factor. There are statistical tests for th…

Hi Robin, Im afraid I am not entirely sure how these are calculated. All I can say is that in the contrast analysis, the comparisons are conducted as one whole, which means that there are more groups being considered than just the 2 groups that are …

Hi Michael, To add to EJ's response (we are working on the mentioned project together), there are several Bayes factors to consider: The direct Bayes factor which compares 1 model against 1 model (this is what you get in the main table). The inclusi…

Hi RobinM, The contrast analysis and post hoc tests basically conduct ttests on the subsets of your data (comparing one group to another, based on 1 or more categorical variables). For an example, see the attached screenshot: https://forum.cogsci.n…

Hi Francesca, That's great to hear! This is indeed where things are not very clear, because there are basically two approaches you can use here: 1) Compare the full model to the full model without sex (as we discussed above). This gives an indicatio…

Hi Francesca, 1) Due to the algorithms used to compute these Bayes factors (there is some random sampling involved), there will be some slight fluctuations between each repeated result. The error % column in JASP gives an indication of how heavy the…

Hi Francesca, Unfortunately this behavior is no bug, but simply a consequence of having a model with 14 covariates. With this many variables, there are 2^15 = 32768 possible models to consider. When using the BayesFactor package in R to enumerate a…

Hi Tom, I suspect there is a bug in the frequentist linear regression analysis, because this particular analysis does not allow the specification of categorical predictors (and in this case just mistakenly treats it as continuous). If you want to co…

@EJ we resolved the issue over email, the issue was not the flipping, but that the test value was not taken into account (and just set to 0). The nightlies should already contain the fix, and Joris informed me that the windows nightly will be workin…

Hi Max, I fixed it and ran the correct code, see below! https://forum.cogsci.nl/uploads/706/P3XSSHS73VDU.png

Yes, something is wrong, I fixed it now. The test value was not considered correctly for the one sample wilcoxon...

Hi Max, I just looked, and the BF's I get for the onesample Wilcoxon tests seem to be in line with the frequentist and parametric results. Would you comfortable sharing your data set with me? That way I can take a closer look. You can also send it …

Hi Max, Could you rerun this with the last version of JASP (0.14)? I changed the underlying sampling algorithm, since it had a bug that would sometimes lead to very conservative results, just like you are describing. If you still have this issue ple…