025.431: The Dewey blog

Overlapping Spans in WebDewey

In WebDewey, when a number is displayed in the "hierarchy box," above it are displayed its parent, its parent's parent, its parent's parent's parent, etc., while below it are displayed all the numbers for which it is the parent.  Sometimes you might be a little surprised by what you see or don't see there.  This is particularly the case when spans are involved -- and more particularly the case when overlapping spans are involved.

For example, when 220-290 is displayed, we find above it 200; we find below it 220, 230-280, and 290.

When 230-280 becomes the focal notation, we find above it 200 and 220-290; we find below it 230-270 and 250-280.

When 230-270 becomes the focal notation, we find above it 200, 220-290, and 230-280; we find below it 230 and 240.

But when 250-280 becomes the focal notation, we find above it 200, 220-290, and 230-280; we find below it 250, 260, and 270-280.

The situation at 230-270 (as compared to the situation at 250-280) may seem odd, but it is, in fact, correct.  After all, there is an entry for 230-270 Specific elements of Christianity, and its parent is 230-280, as shown.

But why are 250, 260, and 270 not shown as children of 230-270?  Because a DDC notation can have only one parent designated in the MARC classification record (153 field, subfield e).  The two spans, 230-270 and 250-280, have equal claim as candidate parents for 250 and 260; the two spans, 230-270 and 270-280, have equal claim as candidate parents of 270.  But in each case only one of the candidates can be designated the parent.  It so happens that 250-280 has been designated the parent of both 250 and 260, while 270-280 has been designated the parent of 270.

The problem arises because of overlapping spans.  The graphic below shows the overlapping of spans that occurs in the 200s:

As can be seen, 230-270 overlaps with both 250-280 and 270-280.  Fortunately, there are very few cases of overlapping spans.  But when you see something in a hierarchy that at first glance looks odd, consider whether any spans are involved, and remember that any DDC number or span of numbers can have only one parent.

Cookbooks: Vegetarian Soup, Chicken Soup

Where to classify works on cooking vegetarian soups?  Browsing the Relative Index for "soups" yields:

Soups                 641.81/3
Soups—cooking    641.81/3

Browsing the Relative Index for "Vegetarian cooking" yields:

Vegetarian cooking     641.5/636

In the upward hierarchy for 641.5636 Vegetarian cooking is 641.5 Cooking.  In the record for 641.5 is the see reference: "For cooking specific kinds of dishes, preparing beverages, see 641.8."  That see reference has hierarchical force; hence works about cooking vegetarian soups are classed in 641.813 Soups.  Examples are Vegetarian Soups and 365 Vegetarian Soups. For these works, the first LCSH is "Soups," and the second is "Vegetarian cooking." For works like these, to provide additional access beyond that provided by the standard DDC number 641.813 in MARC field 082 - Dewey Decimal Classification Number, one could put the additional DDC number 641.5636 in the MARC field 083 - Additional Dewey Decimal Classification Number.

What about chicken soup?  Browsing the Relative Index for "chicken" yields (among other things):

Chicken (Meat)—cooking 641.6/65

In the upward hierarchy for the built number 641.665 Poultry (Meat)—cooking is 641.6 Cooking specific materials. In the record for 641.6 is the class-elsewhere note: "Class specific kinds of dishes featuring specific materials in 641.8."  That note also has hierarchical force.  Hence cooking chicken soup is classed with cooking soup in 641.813 Soups.  Examples are The Chicken Soup Book: Old and New Recipes from around the World and Chicken Soup: 38 International Recipes from Traditional to Contemporary. For these works, the first LCSH is "Soups," and the second is "Cooking (Chicken)." For works like these, to provide additional access, one could put the additional DDC number 641.665 in the MARC field 083.

Polio: Outbreaks, Vaccination, Eradication Effort

The polio outbreak in Syria has been in the news, e.g., "Syria Polio Outbreak Confirmed by WHO" (BBC).  That is a setback for the Global Polio Eradication Initiative!  Here is the summary given on World Polio Day (24 October 2013), before the cases in Syria were confirmed:

In 2013, there are reasons both for celebration and concern.

There has been remarkable progress over the last year, bringing us closer than ever to achieving a polio-free world:
•    Wild poliovirus (WPV) cases in Nigeria, Afghanistan and Pakistan – the last three endemic countries – are down 40% compared to this time last year. Poliovirus in these countries continues to be geographically restricted.
•    WPV type 3 (WPV3) has not been detected anywhere in the world since November 2012.
•    Afghanistan may have succeeded in halting endemic poliovirus circulation, with no cases in the traditionally endemic Southern Region since November 2012.

The polio program is preparing now to take advantage of the upcoming annual "low season" for polio transmission in early 2014: a critical opportunity to capitalize on progress and interrupt transmission in endemic countries.

At the same time, however, the urgency of interrupting transmission in these countries is only reinforced by the tapering outbreak in the Horn of Africa and this week’s reports of two suspected polio cases in Syria. As long as polio remains endemic anywhere, children everywhere will remain at risk. If children in the remaining endemic areas can be reached, the end of polio will follow, protecting children everywhere from this disease and paving the way for delivery of other life-saving interventions.

The NBC news story "Syria Polio Outbreak a Heartbreaking Setback in Struggle against Merciless Virus" begins:

Teams of volunteers are being sent to seven Middle Eastern countries to vaccinate people against polio after an outbreak in eastern Syria paralyzed at least 10 young children.

Browsing the Relative Index for "polio" leads to these entries (among others):

Poliomyelitis—incidence 614.5/49
Poliomyelitis—medicine 616.8/35

The record for 614.549 Poliomyelitis has in its upward hierarchy:

614.5   Incidence of and public measures to prevent specific diseases and kinds of diseases
614.54    Miscellaneous diseases

What about vaccination as a measure to prevent polio? Browsing the Relative Index for "vaccination" yields:

Vaccination—disease control 614.4/7

The record for 614.47 Immunization has the class-here note: "Class here vaccination."  In its upward hierarchy is the record for 614.4 Incidence of and public measures to prevent disease.  That record has a see reference: "For incidence of and public measures to prevent specific diseases and kinds of diseases, see 614.5."  Those notes have hierarchical force.  Hence both incidence of polio and vaccination against polio are classed in 614.549 Poliomyelitis.  An example of a work classed in 614.549 (plus standard subdivision) is The End of Polio: A Global Effort to End a Disease, which is classed in 614.5490222 Poliomyelitis—pictures (built with 614.549 plus T1—0222 Pictures and related illustrations).  The LCSH is "Poliomyelitis" plus the form subdivision "Pictorial works."

The other Relative Index entry cited above (Poliomyelitis—medicine 616.8/35), with its subheading "medicine," indicates that the comprehensive medicine number for polio is 616.835 Poliomyelitis. An example of a comprehensive work classed in 616.835 (plus standard subdivision) is Polio, which is classed in 616.835009 Medical history of polio, built with 616.835 plus 616.1-616.9:009 History, geographic treatment, biography, as instructed in the add footnote at 616.835 and under 616.1-616.9 Specific diseases.   The first LCSH is "Poliomyelitis" plus the topical subdivision "History" and the form subdivision "Juvenile literature."

See also earlier blog entries about efforts to control other communicable diseases: measles, influenza, and cholera.