EJ
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I think you've since reported this on our GitHub page and we're implementing it... E.J.
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Also, when in doubt, you can compare output from R to that of JASP. Cheers, E.J.
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There's a 2009 paper in Psychonomic Bulletin & Review by Rouder & Morey: @ARTICLE{RouderEtAl2009Ttest, AUTHOR = {Rouder, J. N. and Speckman, P. L. and Sun, D. and Morey, R. D. and Iverson, G.}, TITLE = {{B}ayesian $t$ Tests for Accep…
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Hi Joe, population effect size delta = population mu / population sd. So it's the population equivalent of Cohen's d (which is a summary based on the sample, not an inference) Cheers, E.J.
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wrt 2: "likelihood" usually refers to something proportional to p(y|theta); so it has a technical connotation that does not match this particular context. wrt 3: Correct, with estimation there isn't a pair of hypotheses -- there is only th…
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Looks very nice! I love the idea of the annotations in general. Will pass this on to the lab as a recommended way to include explanations in tutorial papers. A few suggestions for improvement: I guess you could say that the posterior under H1 is &qu…
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I'd like to add that, although it is customary to center the prior distribution around the test-value, this is by no means required. In JASP, the t-tests, binomial, multinomial (next release), and AB test (next release) all allow the location of the…
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Hi Chris, That's exactly right. This is called the Savage-Dickey density ratio, and it is a convenient way to "see" a Bayes factor for H0 vs H1 without needing to compute the prior predictive adequacy for H0 and H1 separately. See for inst…
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yes yes Not sure; what I see from the table is that "Size" is the only factor for which the data offer support (and they do so in compelling fashion) With many factors and interactions, the inclusion ("analysis of effects") appro…
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If you are interested in the interaction, you can also compare the 2-main effect model against the full model. With few models you don't always need the inclusion BF. Cheers, E.J.
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Dear August, The ANOVA as borrowed from the BayesFactor package is really a linear mixed model. But in general, the same assumptions apply as they do for the frequentist version. Yes, the Bayesian approach generally allows all sorts of more flexible…
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What needs to be normal is the distribution of variances across subjects, right? I don't see why that wouldn't be (approximately) normal. In your RM ANOVA, I am not sure how your ultimate test involves the variance across the x,y,z. The interaction …
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Hi Richard, So far, as you indicate, JASP has focused mostly on the *evidence*, that is, the relative predictive performance for two competing hypotheses (aka the Bayes factor). The reason that we have not put in prior for the hypotheses is that the…
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I have attended the relevant JASP team members to this forum entry...
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I've passed this on...
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Yes. Depends how principled you are about the principle of marginality, I guess :-) E.J.
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Ah I see. Well but then you can simple compute the sample variance per subject and t-test this between the groups? Of course this ignores the uncertainty about the sample variance, but that would be the approach that people are often using currently…
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I'll attend him to your post
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This particular analysis includes a numerical routine. This means that unless you take an infinite number of samples (which takes an infinite amount of time) the results will change a little bit from one run to the next. The extent to which the resu…
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Yes, it's an issue of numerical precision. Apparently the posterior mass of the models *excluding* that main effect sums to epsilon, with epsilon so close to zero that the number cannot be represented on your computer. E.J.
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For an intuitive idea of when a Bayes factor is compelling see https://www.bayesianspectacles.org/lets-poke-a-pizza-a-new-cartoon-to-explain-the-strength-of-evidence-in-a-bayes-factor/ Cheers, E.J.
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Hi perdavidson, Sorry for the tardy response. Going by the main output table, the null seems to get most support from the data. The "only-Emo" model and "only-Villkor" models also get some support, but a factor of 4 to 5 less. Al…
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Sorry for the tardy response. We are very close to a new version (a week from now) and I hope this solves your problem. But, in general, for bug reports and feature requests we hope you can use our GitHub page -- this way the problem is accessible t…
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Hmm this is interesting, I'll pass this on. Cheers, E.J.
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Hi Adam, No I don't think that this is valid in general, although I would not be surprised if it is a fairly good approximation under many circumstances. This would be an interesting topic for a statistical study. Well you'd need an interval or SE…
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Dear Hongxia, This is briefly described here (for the case of ANOVA): https://link.springer.com/content/pdf/10.3758%2Fs13423-017-1323-7.pdf We have almost finished a paper explaining these concepts for regression in more detail. Furthermore: We have…
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Hi HMStat, To facilitate the discussion it would be great it you could show a screenshot. We are working on ANOVA help files for the next release, so this may come in handy. Cheers, E.J.
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Yes, that could work. The next version of JASP will have posterior distributions for the ANOVA/ANCOVA. Cheers, E.J.
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:-) The real thing is a direct comparison of variances. We have something really cool under development here (there will be a blog post and a preprint once it's done), but there is also recent work in the Tilburg lab of Joris Mulder. This is not in …
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Hi Vanessa, There may be people out here to assist with this general stats question, but doing so is not really the purpose of this forum. However, there is some good news too: in order to assist you with questions such as these, we are setting up a…