Comments on: What’s New in Pubmed? Nothing! http://synthesis.williamgunn.org/2007/12/05/whats-new-in-pubmed-nothing/ A synthesis of ideas about open science and social technology. Wed, 18 Jan 2012 20:57:43 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Martin http://synthesis.williamgunn.org/2007/12/05/whats-new-in-pubmed-nothing/comment-page-1/#comment-1316 Martin Fri, 11 Jan 2008 22:44:19 +0000 http://synthesis.williamgunn.org/2007/12/05/whats-new-in-pubmed-nothing/#comment-1316 Well, assigning mesh terms is done manually - and this process takes time. I've done some work on this and found that indexing the big 5 journals in the field of cardiovascular medicine (i.e. a block buster topic) can easily take 2 weeks. Well, assigning mesh terms is done manually – and this process takes time. I’ve done some work on this and found that indexing the big 5 journals in the field of cardiovascular medicine (i.e. a block buster topic) can easily take 2 weeks.

]]> By: Mr. Gunn http://synthesis.williamgunn.org/2007/12/05/whats-new-in-pubmed-nothing/comment-page-1/#comment-1312 Mr. Gunn Fri, 11 Jan 2008 17:59:43 +0000 http://synthesis.williamgunn.org/2007/12/05/whats-new-in-pubmed-nothing/#comment-1312 Thanks, Martin, for that information. The issue I was trying to resolve is whether or not the categories were in fact considered to be non-overlapping. Because an OR search of all three yields less than the sum of OR searches of the three individually, that proves that the categories are overlapping to a small degree. The purpose of this exercise was to figure out how Pubmed uses the different categories and how MeSH searches compare with non-MeSH, since my previous saved searches began to yield 0 results. The original goal was to find a Pubmed query that returned all results containing any of the three more or less synonymous terms multipotent stromal cells, mesenchymal stem cells, and marrow stromal cells. The expected behavior was that a search for any of the three terms using MeSH would return an identical set of results. It turns out that only one is a MeSH term, but I also found, as you mention, that using MeSH terms doesn't return the latest content, so I've stopped using them for my "What's New" searches. Thanks, Martin, for that information. The issue I was trying to resolve is whether or not the categories were in fact considered to be non-overlapping. Because an OR search of all three yields less than the sum of OR searches of the three individually, that proves that the categories are overlapping to a small degree. The purpose of this exercise was to figure out how Pubmed uses the different categories and how MeSH searches compare with non-MeSH, since my previous saved searches began to yield 0 results.

The original goal was to find a Pubmed query that returned all results containing any of the three more or less synonymous terms multipotent stromal cells, mesenchymal stem cells, and marrow stromal cells. The expected behavior was that a search for any of the three terms using MeSH would return an identical set of results. It turns out that only one is a MeSH term, but I also found, as you mention, that using MeSH terms doesn’t return the latest content, so I’ve stopped using them for my “What’s New” searches.

]]> By: Martin http://synthesis.williamgunn.org/2007/12/05/whats-new-in-pubmed-nothing/comment-page-1/#comment-1306 Martin Fri, 11 Jan 2008 15:42:42 +0000 http://synthesis.williamgunn.org/2007/12/05/whats-new-in-pubmed-nothing/#comment-1306 I think you are fundamentally wrong about "losing" results. As an article can be in both categories, the result of ORing all hits can of course be less than the numbers added. Using AND does make no sense at all! The problem with new and old MESH terms is that old terms are not updated. In general: if you want to search the latest content (which has not been indexed with a MESH) or search more sensitive, don't use a MESH. If you want to search specifically and don't care about the latest stuff: use MESH. I think you are fundamentally wrong about “losing” results. As an article can be in both categories, the result of ORing all hits can of course be less than the numbers added.
Using AND does make no sense at all!
The problem with new and old MESH terms is that old terms are not updated.
In general: if you want to search the latest content (which has not been indexed with a MESH) or search more sensitive, don’t use a MESH. If you want to search specifically and don’t care about the latest stuff: use MESH.

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