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<!DOCTYPE HTML PUBLIC "html.dtd"><HTML><HEAD><TITLE>Presenting XML:Creating an XML Museum Information Application:EarthWeb Inc.-</TITLE><META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW"><SCRIPT><!--function displayWindow(url, width, height) { var Win = window.open(url,"displayWindow",'width=' + width +',height=' + height + ',resizable=1,scrollbars=yes');}//--></SCRIPT></HEAD><BODY BGCOLOR="#FFFFFF" VLINK="#DD0000" TEXT="#000000" LINK="#DD0000" ALINK="#FF0000"><TD WIDTH="540" VALIGN="TOP"><!-- <CENTER><TABLE><TR><TD><FORM METHOD="GET" ACTION="http://search.itknowledge.com/excite/cgi-bin/AT-foldocsearch.cgi"><INPUT NAME="search" SIZE="20" VALUE=""><BR><CENTER><INPUT NAME="searchButton" TYPE="submit" VALUE="Glossary Search"></CENTER><INPUT NAME="source" TYPE="hidden" VALUE="local" CHECKED> <INPUT NAME="bltext" TYPE="hidden" VALUE="Back to Search"><INPUT NAME="sp" TYPE="hidden" VALUE="sp"></FORM></TD><TD><IMG SRC="http://www.itknowledge.com/images/dotclear.gif" WIDTH="15" HEIGHT="1"></TD><TD><FORM METHOD="POST" ACTION="http://search.itknowledge.com/excite/cgi-bin/AT-subscriptionsearch.cgi"><INPUT NAME="search" SIZE="20" VALUE=""><BR><CENTER><INPUT NAME="searchButton" TYPE="submit" VALUE=" Book Search "></CENTER><INPUT NAME="source" TYPE="hidden" VALUE="local" CHECKED> <INPUT NAME="backlink" TYPE="hidden" VALUE="http://search.itknowledge.com:80/excite/AT-subscriptionquery.html"><INPUT NAME="bltext" TYPE="hidden" VALUE="Back to Search"><INPUT NAME="sp" TYPE="hidden" VALUE="sp"></FORM></TD></TR></TABLE></CENTER> --><!-- ISBN=1575213346 //--><!-- TITLE=Presenting XML//--><!-- AUTHOR=Richard Light//--><!-- PUBLISHER=Macmillan Computer Publishing//--><!-- IMPRINT=Sams//--><!-- CHAPTER=14 //--><!-- PAGES=0263-0282 //--><!-- UNASSIGNED1 //--><!-- UNASSIGNED2 //--><P><CENTER><A HREF="../ch13/0260-0262.html">Previous</A> | <A HREF="../ewtoc.html">Table of Contents</A> | <A HREF="0269-0272.html">Next</A></CENTER></P><A NAME="PAGENUM-263"><P>Page 263</P></A><H3><A NAME="ch14_ 1">CHAPTER 4</A></H3><H2>Creating an XML<BR> Museum Information Application</H2><B>by Richard Light</B><P>In this chapter I examine an industry-specific(or vertical) application of XML—museum information systems.Although museums do not at first glance have much incommon with commercial or technical applications of XML,they have the following features that will apply to many areasof application:</P><UL><LI> The information that each institution holds aboutits collections is mission-critical and long-term;the objects in the collection are of little value andcannot be managed without associated information resources.</UL><A NAME="PAGENUM-264"><P>Page 264</P></A><UL><LI> The information associated with each object is variable in natureand can be very complex. It will routinely include a variety of formatsand media.<LI> Each institution wants to have a documentation system thatmatches its own requirements and circumstances exactly.<LI> Conversely, museums regularly need to interchange informationabout objects, exhibition facilities, and so on.<LI> There is a regular need to deliver selected parts of museums'information to a variety of publics in an increasing number ofdelivery formats.<LI> Most museums have very little money to spend oncomputer-based documentation systems!</UL><H3><A NAME="ch14_ 2">Interchanging Structured Museum Catalog Records</A></H3><P>Museums have tended to cooperate rather than compete when it comesto defining logical data structures for their object records. In this section, Idiscuss an example of an interchange framework for structured museumcatalog records, and I show how it could be implemented in XML.</P><H4><A NAME="ch14_ 3">Example: The SPECTRUM Standard</A></H4><P>In the United Kingdom, for example, a single framework—theSPECTRUM standard—covers all the disciplines represented in museum work. To giveyou an idea of the range, these disciplines include the following:</P><UL><LI> Archaeology<LI> Biology<LI> Decorative arts<LI> Fine arts<LI> Industrial archaeology<LI> Paleontology<LI> Social history</UL><P>SPECTRUM describes the collections management processes thatmuseum objects might be subjected to and the information associated with eachactivity.</P><A NAME="PAGENUM-265"><P>Page 265</P></A><BR>It is a generalized framework that can be implemented in both manualand automated documentation systems. In the case of automated systems,museums are free to use whatever software they have available.<P>Figure 14.1 shows a sample page from SPECTRUM that lists some ofthe information that should be recorded when setting up an exhibit.<BR></P><A HREF="javascript:displayWindow('images/ch14fg01.jpg',288,204)"><IMG SRC="images/tn_ch14fg01.jpg"></A><BR>Figure 14.1.<BR>SPECTRUM concepts for exhibits.<BR><P>Figure 14.2 covers the detailed requirements for a single concept—Briefdescription. The requirements for this concept include the following:</P><UL><LI> Definition: What the concept means<LI> How to record: Guidelines on the method to use when enteringthis information<LI> Examples: One or more concrete examples<LI> Use: How often, or in what circumstances, this information shouldbe recorded<LI> Required in: The collections management procedures to whichthis information is relevant<LI> Alternatives: Other names that have been used for this conceptwithin museum standards and systems</UL><A NAME="PAGENUM-266"><P>Page 266</P></A><BR>Figure 14.2.<BR><A HREF="javascript:displayWindow('images/ch14fg02.jpg',288,204)"><IMG SRC="images/tn_ch14fg02.jpg"></A><BR>SPECTRUM definition of the Brief description concept.<BR><H4><A NAME="ch14_ 4">XML as an Interchange Format</A></H4><P>Different museums have implemented SPECTRUM in different ways,which is fine while the information stays inside the museum. As soon as it needsto travel, however, a variety of implementations causes problems, which canhappen quite often.</P><P>For example, one curator might be researching long case clocks for anexhibit that she is planning. She might request full information on the long caseclocks in three other collections. Ideally, she wants to be able to receive thisinformation in a form that is immediately useable within her own collectionmanagement system. XML can help in this situation.</P><P>By designing an XML DTD that reflects SPECTRUM's logicalinformation structure, you can set up an interchange format for museum objectinformation. Each museum will then have two jobs to do (or its software supplierwill). They need to do the following:</P><UL><LI> Write an export procedure that outputs records in the agreedXML format.<LI> Write an import procedure that reads the XML and converts it tothe in-house format.</UL><A NAME="PAGENUM-267"><P>Page 267</P></A><P>Armed with these export and import procedures, museums will be able tofreely interchange object information. All the data each museum receives willbe directly useable within its native collection management system. UsingXML means that the requesting and delivery of this information can take placeover the Internet, which removes the need for a dedicated communications network.</P><P>This scenario could be repeated in many other application areas. The keycomponent, without which it won't work, is an agreed framework forinformation interchange. If that framework exists, it can be represented in XML.</P><P>This approach doesn't require that everyone who participates has to workto some impossibly high standard of recording, nor does it require that theychange their current methods of doing business in any way. It simply mandatesan interchange format for the information that they wish toshare.</P><H3><A NAME="ch14_ 5">An XML DTD for SPECTRUM</A></H3><P>Now take a minute to think about the design of the interchange DTDfor SPECTRUM information. SPECTRUM is expressed in neutral terms. Itwill usually be implemented using a relational schema. To package upSPECTRUM information for interchange, you need to ensure that the packagingprocess doesn't lose any key information.</P><P>At the highest level, it makes sense to see the package as containing zeroor more object records. The following code calls the package an"object set":</P><!-- CODE SNIP //--><PRE><!ELEMENT OBJECT-SET (OBJECT*) ></PRE><!-- END CODE SNIP //--><P>To decide how to organize the information about each object, go back toSPECTRUM itself. There you find that the information categories are groupedby type. Figure 14.3 shows the "Object identification information"grouping, within which your Brief description concept is located.</P><P>The analysis gives you a simple two-level structure for object information.Most of the groupings, such as the following, can easily be mapped to level-1elements within object:</P><UL><LI> Record information<LI> Amendment history<LI> Object identification information<LI> Object description information<LI> Object production information</UL><A NAME="PAGENUM-268"><P>Page 268</P></A><UL><LI> Object collection information<LI> References<BR></UL><A HREF="javascript:displayWindow('images/ch14fg03.jpg',288,204)"><IMG SRC="images/tn_ch14fg03.jpg"></A><BR>Figure 14.3.<BR>SPECTRUM "Object identification information" concepts.<BR><P>A closer examination of the following few concepts shows that they arecomplex structures that actually occur at level 2:</P><UL><LI> Address<LI> Date<LI> Organization<LI> People<LI> Person<LI> Place</UL><P>Because these occur frequently, they were placed in the level-1 list toavoid repetition. However, since they really belong at level 2, you don't needthem in your level-1 content model.</P><P><CENTER><A HREF="../ch13/0260-0262.html">Previous</A> | <A HREF="../ewtoc.html">Table of Contents</A> | <A HREF="0269-0272.html">Next</A></CENTER></P></TD></TR></TABLE></BODY></HTML>⌨️ 快捷键说明
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