From skelly@paradise.net.nz Wed Aug 2 02:40:02 2000 Received: from mxu4.u.washington.edu (mxu4.u.washington.edu [140.142.33.8]) by lists.u.washington.edu (8.9.3+UW00.05/8.9.3+UW99.09) with ESMTP id CAA22958 for ; Wed, 2 Aug 2000 02:40:00 -0700 Received: from deborah.paradise.net.nz (deborah.paradise.net.nz [203.96.152.32]) by mxu4.u.washington.edu (8.9.3+UW00.02/8.9.3+UW99.09) with ESMTP id CAA21626 for ; Wed, 2 Aug 2000 02:39:54 -0700 Received: from Chris (203-79-93-124.tnt11.paradise.net.nz [203.79.93.124]) by deborah.paradise.net.nz (8.10.1/8.10.1) with SMTP id e729dlL14492 for ; Wed, 2 Aug 2000 21:39:47 +1200 (NZST) Message-ID: <002901bffc64$156f2d40$ec1dfea9@Chris> From: "Chris Skelly" To: References: Subject: Re: WAPHGIS: Jenk's Method Date: Wed, 2 Aug 2000 21:28:56 +1200 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 5.00.2615.200 X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2615.200 Yes, us geographers have something called "GeoAbstracts". Last time I used them (1997), they were still big heavy books - at least our library did not have a computer version. There is a computerised search tool called GeoBase, which goes wider than just the GeoAbstracts, but I don't know if you can get GeoAbstracts directly as a computerised search tool. Cheers, Chris ----- Original Message ----- From: Dick Hoskins To: Sent: Wednesday, August 02, 2000 8:27 AM Subject: RE: WAPHGIS: Jenk's Method > Thanks a lot. These look very useful. Where are geographic journals > indexed? Is there a "Medline" for geography and GIS on the Web? > > > -----Original Message----- > From: WAPHGIS-owner@u.washington.edu > [mailto:WAPHGIS-owner@u.washington.edu]On Behalf Of Lance Waller > Sent: Tuesday, August 01, 2000 12:11 PM > To: waphgis@u.washington.edu; lwaller > Subject: Re: WAPHGIS: Jenk's Method > > > Dear waphgisers: > > I did a search on Web of Science to see who has referenced > the Smith (86) paper and the following appeared in the list. > > I have not read many of these, but > several relate to disease atlases. > > Lance > > > > The classification of ordinal data for choropleth mapping > Cromley RG, Mrozinski RD > CARTOGRAPHIC JOURNAL > 36: (2) 101-109 DEC 1999 > > An analysis of alternative classification schemes for medical atlas mapping > Cromley EK, Cromley RG > EUROPEAN JOURNAL OF CANCER > 32A: (9) 1551-1559 AUG 1996 > > A cognitive subtask model of statistical map reading > Herrmann D, Pickle LW > VISUAL COGNITION > 3: (2) 165-190 JUN 1996 > > A comparison of optimal classification strategies for choroplethic displays > of spatially > aggregated data > Cromley RG > INTERNATIONAL JOURNAL OF GEOGRAPHICAL INFORMATION SYSTEMS > 10: (4) 405-424 JUN 1996 > > Statistical choropleth cartography in epidemiology > Indrayan A, Kumar R > INTERNATIONAL JOURNAL OF EPIDEMIOLOGY > 25: (1) 181-189 FEB 1996 > > PERCEPTION OF CLUSTERS IN STATISTICAL MAPS > LEWANDOWSKY S, HERRMANN DJ, BEHRENS JT, LI SC, PICKLE L, JOBE JB > APPLIED COGNITIVE PSYCHOLOGY > 7: (6) 533-551 NOV 1993 > > MAP-USER RESPONSE TO COMPUTER-GENERATED CHOROPLETH MAPS - COMPARATIVE > EXPERIMENTS IN > CLASSIFICATION AND SYMBOLIZATION > MAK K, COULSON MRC > CARTOGRAPHY AND GEOGRAPHIC INFORMATION SYSTEMS > 18: (2) 109-124 APR 1991 > > "Hoskins, Richard" wrote: > > > > I just finished reading the Smith paper referred to below. Pretty > > intresting. I'd be interested in finding some more recent work on this > topic > > of selecting class intervals. Is anyone familiar with methods in which > > classes can be displayed that are "conditioned" on the values of other > > covariates? Examples? > > > > Dick Hoskins > > > > -----Original Message----- > > From: fpb01@health.state.ny.us [mailto:fpb01@health.state.ny.us] > > Sent: Monday, July 24, 2000 8:52 AM > > To: waphgis@u.washington.edu > > Subject: Jenk's Method > > > > For decades cartographers have drawn histograms of data distributions, > seen > > how sometimes the data points form clusters, and selected these "natural > > breaks" as their class breaks. Jenk's Method is the formal mathematical > > expression of this technique. It defines categories that have the highest > > within-category similarity and between-category dissimilarity. > > > > Jenk's Method works well for data with multimodal and highly skewed > > distributions. It does not put dissimilar values together in the same > > category, which occasionally happens when using quantiles. > > > > See Richard Smith, "Comparing Traditional Methods for Selecting Class > > Intervals on Choropleth Maps", The Professional Geographer 38(1986): > 62-67. > > > > If you make a map in either MapInfo or ArcView and choose "natural > breaks", > > you are using Jenk's Method. > > > > Frank Boscoe > > NYS Department of Health > > .