Subject classification exercise: part 2
First, confirm the task begun last week.
Last week, you selected a subset of 30-40 concepts from the following list to define a more specific,
cohesive subject area.
Do you still remember and agree upon:
 Your group’s definition of the subject area you’ve selected.
 How the concepts you’ve chosen express that definition.
Think about this task as making a case, or creating an argument, for a particular subject definition. For
example, you might define “lifestyle gardening” as planning and enjoying one’s garden, but not performing
actual tasks with plants, which would be delegated to one’s gardener. So you might include concepts for
types of gardens (planning what to do) and activities that take place in gardens (barbecues) and skip
concepts for dealing with pests, and so on.
Next, arrange your subject concepts into a classificatory structure.
1.
2.
3.
Label your subject. (Such as “Garden fun” or “Gardening with native Texas plants” and so on.)
Determine the macro structure. One hierarchy? Multiple parallel hierarchies? Strict hierarchy
(genus-species or part-whole relationships only)? Loose tree? What are the relative advantages of
different options?
Arrange your concepts in the macro structure. Pay attention to the principles of division at each
level of the structure and be able to explain them. Also think about potential orders within each
array (hierarchy level).
Use your index cards to display your structure.
Third, report your findings to the group.
In five minutes or less, tell the rest of the class:



Your subject label and definition.
The rationale you employed to select concepts for your subject.
Your structural and arrangement strategy.
And be prepared to use your experience with this activity to contribute to a class discussion on
classification and classification design.
The following pages include some review and tips about classification structure.
Notes for structuring classification concepts
This reprises some information from our lecture last week, plus a little bit more. (We’ll review order in
arrays in our next class session, when we also discuss facet analysis in depth.)
Classification structures



Single hierarchy: all terms are related to one top term, or root node (in biological taxonomy of
species, the root node would be “living organisms” and proceed from there).
Multiple hierarchies: multiple top terms are employed to represent different kinds or thematic
areas (like the gene ontology has three different subontologies for cell components, biological
processes, and metabolic functions, or the Dewey Decimal classification has ten (it’s decimal!) top
terms for broad disciplinary divisions, including Social Science, Science, Religion, and Arts and
Recreation).
Faceted classification: multiple top terms indicate different component types, or facets, that are
combined to make synthetic classes. The component facets usually represent fundamental types
(like space, time, substances, processes, roles) and not concept areas (like intellectual property or
labor rights). Terms within a facet may be themselves arranged in hierarchies; a faceted
classification appears similar to one with multiple hierarchies. The difference is that facets are
meant to be orthogonal—independent of each other (not like Science and Social Science in the
Dewey Decimal Classification, which are both disciplines, but like Products [e.g., bread or
furniture] and Processes [like baking or carpentry], which are of different kinds). (We’ll discuss
facet analysis in depth in our next class.)
Classificatory relationships
Hierarchical relationships involve three primary types:
 Genus to species, or broader to narrower: the _IsA relationship. A dog (narrower) is a canine
(broader). Strict hierarchies demonstrate inheritance of characteristics down the tree. A canine
(narrower) is a mammal (broader); therefore, what is true about mammals will be true for dogs as
well. The tree relationship described by Kwasnik does not include this inheritance; what’s true of a
general is not necessarily true of a private. However, the relationship from general to colonel all
the way down to private is consistently maintained: colonels are lesser rank than generals who are
lesser rank than majors, and so on.
 Part to whole. A steering wheel is part of a car; a nucleus is part of a cell.
 Instance: The Mediterranean is an instance of a sea; Texas is an instance of a state. Texas is not
part of a state, nor is it a kind of state; it is a specific state. The Mediterranean is not part of a sea,
nor is it a kind of sea; it is a specific sea. (A county is part of a state; a state without income tax is
a kind of state.)
In a strict hierarchy, at each level, the narrower terms are related to the broader term by the same principle
of division. The narrower terms are jointly exhaustive and mutually exclusive.
Example
Furniture
1.
2.
Holds people
Holds stuff
The principle of division is what is being held; people or stuff. According to this hierarchy, all furniture
either holds people or stuff; it doesn’t (primarily) hold both.
Furniture
1.
Holds people
a. Furniture people sit on
i. Furniture multiple people sit on
2.
ii. Furniture one person sits on
b. Furniture people lie on
Holds stuff
The principles of division here are the posture assumed by people using the furniture, and the number of
people who can use it at once.
Mixing principles of division at a single level of a hierarchy makes the relationships between broader and
narrower terms confusing and potentially overlapping, because different perspectives are being employed at
once.
Furniture
1.
2.
3.
4.
Wooden furniture
Modern furniture
Bedroom furniture
Bookcases
One way to improve this is to make the principles of division clear by adding “node labels”:
Furniture
(by material)
wooden furniture
plastic furniture
(by style)
rococco furniture
modern furniture
(by room)
bedroom furniture
office furniture
(by function)
storage furniture
(by form)
bookcases
tables
desks
wardrobes
bureaus
sleeping furniture
Note another problem with #4: “bookcases” was at a lower level of abstraction than the other terms. In
general, all terms at the same level of a hierarchy should be at a similar level of abstraction, and there
should be consistent degrees between levels (that is, not extensive jumps from very general to very specific,
like from fruit to Jazz apple, or vegetable to hen-of-the-woods mushroom).
Arrangement within arrays
The set of terms at a single level of hierarchy is called an array.
The order within arrays is another means of conveying information; ideally the order should be motivated
(that is, not just alphabetical non-order).
Possible orders within array include:
 Chronological (art styles from Post-Impressionist to Dada to Cubist to Abstract Impressionist)
 Directional (east to west, for example, or closest to farthest)
 Increasing intensity (slowest to fastest music tempos, for example, or lightest to darkest hues)



Increasing concreteness (from more general to more specific, such as from philosophical warrant
to cultural warrant to literary warrant)
Increasing quantity (from one to many)
Order of a process (from plowing to planting to weeding to harvesting, for example)
Tips
Sort like with like.
Try to place like kinds of things together (processes, products, people), not just things that have some
thematic relation. A hierarchy in its strict form takes one kind of thing and goes from the most general
category to the most specific.
this: Animals  domesticated animals  animals raised for food  pigs
this: Agricultural processes  farming  factory farming
this: Effects  effects of farming practices  effects on animals  overcrowding
not this: Animalspastures, pens, cages  overcrowding
not this: Animals factory farming  mercury poisoning
You may need to generate intermediate levels that weren’t explicit in your source concepts.
Example
Source concepts: meat eating, e.coli, cholesterol, sustainability
Hierarchical structure that relates these source concepts
disadvantages of meat eating
health risks
health risks associated with meat eating
high cholesterol
health risks associated with industrial meat production
bacterial contamination
e.coli contamination
unsustainable practices
effects of industrial meat production
consumption of resources
pollution
Subject concepts
1. annuals
2. ants
3. aphids
4. arbors
5. balance
6. barbecues
7. beneficial insects
8. biennials
9. borders
10. budget
11. bulbs
12. canning
13. clay soil
14. color
15. community garden
16. compost
17. container garden
18. croquet
19. curb appeal
20. cuttings
21. deer
22. dethatching
23. drainage
24. edging
25. English garden
26. fence construction
27. fences
28. fertilizer
29. fertilizing
30. flowerbed
31. flowering plants
32. focal points
33. fountains
34. French garden
35. full-shade exposure
36. full-sun exposure
37. garden decor
38. garden design
39. garden furniture
40. garden maintenance
41. garden ornaments
42. garden parties
43. garden services
44. garden shears
45. garden tools
46. gardeners
47. gardening
48. gazebos
49. grasses
50. greenhouse garden
51. growing season
52. harvesting
53. hedges
54. heirloom seeds
55. herbs
56. hoes
57. hydroponic garden
58. irrigation system
59. Japanese garden
60. kitchen garden
61. landscape architects
62. landscaping
63. lawnmowers
64. lawns
65. loam soil
66. manure
67. mowing
68. mulch
69. native plants
70. nooks
71. orchard
72. organic gardening
73. partial-sun exposure
74. patios
75. perennials
76. pergolas
77. pest management
78. pesticides
79. pests
80. plant diseases
81. plant hardiness zones
82. plant nutrition
83. plant placement
84. plant selection
85. planting
86. plants
87. ponds
88. potting
89. preserving
90. pruning
91. rabbits
92. rainwater
93. raised beds
94. rakes
95. rock garden
96. rocky soil
97. roof garden
98. sandy soil
99. seasons
100. seeds
101. shovels
102. shrubs
103. simplicity
104. sodding
105. soil
106. soil acidity
107. soil aeration
108. soil amendments
109. soil fertility
110. soil improvement
111. soil texture
112. sprinkler systems
113. staking
114. terrace
115. texture
116. tilling
117. topiary
118. trees
119. trelllises
120. trowels
121. tubers
122. unity
123. vegetable plants
124. vines
125. water conservation
126. watering
127. weeding
128. weeds
129. weevils
130. windowsill garden
131. worms
132. xeriscaping