tag:blogger.com,1999:blog-3164804243040726299.post3446348055768979573..comments2024-02-26T04:19:22.304-05:00Comments on The EEB & Flow: Null models matter, but what should they look like?Marc Cadottehttp://www.blogger.com/profile/08335319636148357534noreply@blogger.comBlogger5125tag:blogger.com,1999:blog-3164804243040726299.post-86004214954521650222014-05-04T07:13:20.532-04:002014-05-04T07:13:20.532-04:00The discussion about null models in becoming a lit...The discussion about null models in becoming a little boring. When you discard a null model you simply say that your system has more structure than the null model. It is always possible to devise a more complicated model, to discard this model, and then to devise a new more complicated model and so on, ad infininitum. Null models sett a lower limit on the complexity of the problem. Probably it would be more rewarding to see at null models that are NOT discarded, since they seti un UPPER limit t the complexity of your modelHans Castorphttps://www.blogger.com/profile/05016989070891441042noreply@blogger.comtag:blogger.com,1999:blog-3164804243040726299.post-54711598612403524262014-04-24T10:45:39.272-04:002014-04-24T10:45:39.272-04:00Jeremy, I'm not advocating to take comfort in ...Jeremy, I'm not advocating to take comfort in it, I just wanted to point out that the problem is not necessarily in using null models, but rather our apparent inability to correctly interpret a hypothesis test. <br /><br />P-values are misinterpreted pretty much since they are around, and people have been pointing this out for decades to no effect. It's just so convenient to say that p(D<0.05|H0) = p(!H0).<br /><br />It seems to me that exactly the same thing is what we do with null models, if I call my null model N0, abd the alternative "my favorite theory", we say that p(D<0.05|N0) ==> "my favorite theory"<br /><br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3164804243040726299.post-61385986790656192112014-04-23T21:31:05.629-04:002014-04-23T21:31:05.629-04:00Thanks, sorry I missed your earlier post on the to...Thanks, sorry I missed your earlier post on the topic! The problem for me is deciding what is the normal course of progress (we have some null models, it will take a while for more appropriate null models to develop), and what is stasis. Any analytical approach can be misinterpreted, but how long until someone should make a fuss about interpreting it correctly? Caroline Tuckerhttps://www.blogger.com/profile/09319215430054509345noreply@blogger.comtag:blogger.com,1999:blog-3164804243040726299.post-58309296721752722382014-04-22T15:12:01.319-04:002014-04-22T15:12:01.319-04:00Spot on Caroline. And unlike Florian, I don't ...Spot on Caroline. And unlike Florian, I don't take much comfort from the fact that any analytical approach can be misinterpreted...Jeremy Foxhttp://dynamicecology.wordpress.comnoreply@blogger.comtag:blogger.com,1999:blog-3164804243040726299.post-16588143714777299382014-04-22T10:24:53.935-04:002014-04-22T10:24:53.935-04:00Hi Caroline,
good points! Jeremy had a post a whi...Hi Caroline,<br /><br />good points! Jeremy had a post a while ago http://dynamicecology.wordpress.com/2012/08/30/why-do-our-null-models-nullify-some-effects-and-not-others/ with similar points.<br /><br />One could add that the story can also go the other way - not rejecting the null model is no proof that the null model is correct, specially not when the summary statistics that are used are not sufficient for the inferential problem at hand (I'm thinking of neutral theory, for example, where one can show that patterns arising from a niche-structured community can be produced perfectly well by a neutral model).<br /><br />That being said, I want to reemphasize your point that null-models are clearly a big improvement over simple correlative analysis, because they account for all kinds of artifacts that mess up regression analyses. Their results are often over-interpreted, but so are all other statistical methods. If I compare to other statistical approaches (p-values, regression, ...), I would say: the situation is normal.Anonymousnoreply@blogger.com