Melvil Deweys Ingenious Notational System North American Symposium

Melvil Dewey’s Ingenious Notational System North American Symposium on Knowledge Organization June 19, 2009 Rebecca Green Dewey Decimal Classification

Roadmap • Shelf arrangement vs. subject collocation • Decimal notation • Hierarchical organization • Number building • Language-independent representation • Potential for customization

Shelf arrangement in the 1800 s • Institution-specific, using, e. g. , accession order, broad subject classes, size, author name • Duplication of effort • Initial classification • Reclassification

Eureka! • The insight • Use classification scheme to establish relatively fine-grained subject representation • Use decimal notation to govern order of shelf arrangement • Immediate benefits derived from the insight • Institution-independent relative location • Cooperative classification • Linear sequence + hierarchical organization

Decimal notation (1) • DDC 1, 1876 • Every class admitted of division into 9 subclasses (represented 1 -9), plus 0 to represent no division • “No difficulty found in. . . omitting the initial zero; ” some 2 -digit numbers (e. g. , 51 [051]) • Also some 4 -digit numbers (e. g. , 5545 [554. 5]) • Notation incorporated decimal point “as if it were written after the first figure”

Decimal notation (2) • DDC 2, 1885 • Leading zeroes retained • Decimal point between third and fourth digits • Effect • Notation more expressive • Filing order same whether interpreted numerically or alphanumerically

Hierarchical organization (1) • New subjects can be accommodated by notational expansion, e. g. , 005. 75 Specific types of data files and databases 005. 753 Temporal, spatial, constraint databases

Hierarchical organization (2) • Interoperable expansions 2— 455 5 Pisa province (Eng) Provincia di Pisa (It) 2— 455 51 Pisa (Eng) Comune di Pisa (It) 2— 455 523 Nordovest della provincia di Pisa (It) San Guiliano Terme (It)

Hierarchical organization (3) • Flexible granularity 320. 53* 320. 532 2 Political ideologies Collectivism and fascism Communism Marxism-Leninism *Abridged edition stops here

Hierarchical organization (4) • Expressivity of notation • Specificity • Psychology 150 • Emotions of children 155. 4124 • Relationships among subjects • Oats 633. 13 • Rye 633. 14 • Corn 633. 15 • Barley 633. 16

Number building (1) • Mnemonicity • China T 2— 51, 951 • Chinese language T 6— 951, 495. 1 • Chinese literature 895. 1 • Chinese religions 299. 51 • Chinese Communist Party 324. 251075 • Chinese calendar 529. 32951

Number building (2) • Intrafacet relationships Ceramic arts of Jews 738. 089924 738 Ceramic arts 089 Ethnic and national groups (from Table 1) 924 Jews (from Table 5 as instructed under T 1— 08905 -T 1— 08999: Add to base number T 1— 089 notation T 5— 05 -T 5— 9 from Table 5)

Number building (3) • Intrafacet relationships—cont. French masters 759. 4074 759 (Painting and paintings) Historical, geographic, persons treatment 4 France (from Table 2, as instructed at 759. 3 -759. 8 Miscellaneous parts of Europe: Add to base number 759 the numbers following – 4 in notation 43 -48 from Table 2) 074 Exhibitions (from Table 1)

Language-independent representation (1) 713 Landscape architecture of trafficways Arquitectura paisajística de las vías de tráfico Aménagement paysager des voies de communication Landschaftsgestaltung für Verkehrswege Landskapsarkitektur for trafikkårer

Potential for customization (1) • Choice of level of specificity • Shelf arrangement • Full vs. abridged edition • Local practice • Search • Truncated search plus wildcard operator

Potential for customization (2) • Search by subject component, using 085 Synthesized Classification Number Components (MARC bibliographic format) • 085 ## $b 759 $a 759. 3 $c 759. 8 $z 2 $r 4 $t 4 $u 759. 4 • 085 ## $b 759. 4 $z 1 $t 074 $u 759. 4074 • Search on 75* and 2— 44* for French painting and paintings

Potential for customization (3) • Display using personal citation order • Standard citation order in Table 1: place + time • Europe, 19 th century 1— 094034 • Europe, 20 th century 1— 09404 • Asia, 19 th century 1— 095034 • Asia, 20 th century 1— 09504 • Africa, 19 th century 1— 096034 • Africa, 20 th century 1— 09604

Potential for customization (4) • Display using personal citation order • Reverse citation order: time + place • Europe, 19 th century 1— 094 + 034 • Asia, 19 th century 1— 095 + 034 • Africa, 19 th century 1— 096 + 034 • Europe, 20 th century 1— 094 + 04 • Asia, 20 th century 1— 095 + 04 • Africa, 20 th century 1— 096 + 04

Benefits arising from the notation • Large amount of categorized content • Worldwide user community • Language-independent representation • Interoperable translations • Mappings and crosswalks