Entity Modelling

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Levels of Decomposition

When a whole is decomposed into parts then very often we find that the part types can be decomposed further. We have seen this already: sentences can be broken down into words and words into letters. These can be shown on a single diagram — the relationships are stacked, forming a tower, say, as follows:

The decomposition of wholes into parts can continue over many levels. Thus some linguists, for example, speak of five levels of decomposition of a sentence. These are shown in figure 4. For another example in a dictionary you see each word with its different senses defined and so a dictionary is composed of words and these, within the context of a dictionary, are composed of a number of senses1, see figure 5 for the three levels of a dictionary. Figure 6 shows the parts of an atom as understood circa 1930.

  • a sentence is composed of one or more clauses
  • a clause is composed of one or more phrases
  • a phrase is composed of one or more words
  • a word is composed of one or more morphemes
Figure 4
Some linguists describe five levels of decomposition of a sentence
  • a dictionary has one or more words
  • a word has one or more senses
Figure 5
Dictionary Structure
  • an atom is composed of exactly one nucleus and one or more electrons
  • a nucleus is composed of one or more protons and zero, one or more neutrons
Figure 6
From physics

1 For the word sense itself we find no less than ten distinct senses given in the Concise Oxford Dictionary. The 7th sense and the one we intend for it here is this:
sense n... 7. meaning, way in which a word etc. is to be understood, intelligibility or coherence or possession of a meaning