025.431: The Dewey blog

Standard subdivisions and the WebDewey number building tool

Since so much number building in the DDC involves standard subdivisions, understanding how they work with WebDewey’s number building tool is important for any classifier.

First, remember a couple of basics about using standard subdivisions:

• You can use them anywhere unless instructed otherwise
• You should not add one standard subdivision to another
• Where a zero is already used for subdivisions of a number in a schedule, use double zeros for standard subdivisions

As always, the number builder can be very powerful, but it’s not at all hard to create invalid numbers with it. Whenever you’re building a number that doesn’t have other instructions, WebDewey will take you to Table 1. When you’re just starting out, that’s good. But just because WebDewey takes you there doesn’t mean you can necessarily add standard subdivisions.

Try this: go to any potential base number in the schedules without its own add instructions. There are many possible numbers you could use—if you need a suggestion, 636.01 works. Click START in the number builder, and sure enough, you’re taken to Table 1. Now add a single standard subdivision (again without instructions of its own), say T1—05. Click ADD and you’re taken back to Table 1.

The rules of the DDC prevent you from adding further standard subdivisions, but the number builder allows it. Why is that? My #1 reason is that the number builder will never be perfect, and we’d rather let you build some invalid numbers than not build some valid ones. As a local adaptation, you might also choose to ignore the prohibition against adding multiple standard subdivisions, though the EDIT LOCAL button is a better way to handle such practices.

The way the number builder improves is constant iteration. If it prevents you from building a valid number, I want to hear about it so we can look into fixing it! But I hope the above example shows you that building invalid numbers isn’t too hard to do. Beyond standard subdivisions, you can still report cases like that, but we’ll keep erring on the side of letting you build.

If you’re interested in more on this topic, check the blog’s tag for the WebDewey number building tool.

Virtual AskQC Office Hours session on WebDewey

If you've never heard of Virtual AskQC Office Hours, it's a regular, free webinar series from my OCLC colleagues in Metadata Quality. Each monthly topic has two different sessions to accommodate time zone differences. Recordings and slides are made available from previous sessions too.

This month's session is an introduction to classifying with WebDewey. You'll hear from database specialists Robin Six and Bryan Baldus. I'm not presenting, but will be around to field questions, as will a few of our other colleagues.

The first one... just happened! That's on me for not thinking to post about it sooner. But you can still join next week's session, Thursday, June 23, at 4pm US Eastern time. Find registration information here.