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Sloppy identity

Sloppy identity is a biology topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Sloppy identity rather than just read about it. In short: In linguistics, sloppy identity is an interpretive property that is found with verb phrase ellipsis where the identity of the pronoun in an elided VP (verb phrase) is not identical to the antecedent VP. For example, English allows VPs to be elided, as in example (1).

Sloppy identity — main illustration
Sloppy identity — illustration

Key takeaways

  • Sloppy identity belongs to biology; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Sloppy identity to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Sloppy identity from memory before moving on to harder problems.

Reference excerpt

In linguistics, sloppy identity is an interpretive property that is found with verb phrase ellipsis where the identity of the pronoun in an elided VP (verb phrase) is not identical to the antecedent VP. For example, English allows VPs to be elided, as in example (1). The elided VP can be interpreted in at least two ways, as follows:

The "strict" reading: sentence (1) is interpreted as (1a), where the pronoun his denotes the same referent in both the antecedent VP and the elided VP. In (1a), the pronoun his refers to John in both the first and the second clause. This is done by assigning the same index to John and to both the "his" pronouns. This is called the "strict identity" reading because the elided VP is interpreted as being identical to the antecedent VP. The "sloppy" reading: sentence (1) is interpreted as (1b) where the pronoun his refers to John in the first clause, but the pronoun his in the second clause refers to Bob. This is done by assigning a different index to the pronoun his in the two clauses. In the first clause, the pronoun his is co-indexed with John, in the second clause, pronoun his is co-indexed with Bob. This is called the "sloppy identity" reading because the elided VP is not interpreted as identical to the antecedent VP. 1) John scratched his arm and Bob did too. a. Strict reading: Johni scratched hisi arm and Bobj [scratched hisi arm] too. b. Sloppy reading: Johni scratched hisi arm and Bobj [scratched hisj arm] too.

History The discussion of "sloppy identity" amongst linguists dates back to a paper by John Robert Ross in 1967, in which Ross identified the interpretational ambiguity in the elided Verb Phrase of the previously stated sentence 1) found in the intro. Ross tried, without success, to account for "sloppy" identity using strictly syntactic structural relations, and concluded that his theories predicted too many ambiguities. A linguist named Lawrence Bouton (1970) was the first to develop a syntactic explanation of VP-Deletion, commonly referred to by contemporary linguists as VP – ellipsis. Bouton's theory of VP-Deletion and Ross' observation of sloppy identity served as an important foundation for linguists to build on. Many advances followed within the next decade, providing much of the theoretical scaffolding necessary for linguists to address issues of "sloppy identity" up to present day. Most notable of these advances are Lawrence Bouton's VP-Deletion rule (1970), Barbara Partee's "Derived-VP rule" (1975), and Ivan Sag's "Deletion Approach" (1976), based on the Derived-VP rule. Theories beyond Ross's initial discovery have all extended beyond analyses based on observations of structural relations, often using logical form and phonetic form to account of instances of sloppy and strict identity. The deletion (derived VP) approach, in combination with the use of logical form (LF) and phonetic form (PF) components to syntax, is one of the most widely used syntactic analysis of sloppy identity to date.

Analyses

Y model

This model represents the interface level of the phonological system and interpretive system that give us judgements of form and meaning of D-structure. Early theorists seemed to suggest that phonetic form and logical form are two distinct approaches for explaining the derivation of VP ellipsis.

The deletion-at-PF (phonetic form) analysis Scholars like Noam Chomsky (1955), Ross (1969) and Sag (1976) have suggested the process responsible for VP ellipsis is a syntactic deletion rule applied at the level of PF, this process is named as VP Deletion. The PF-deletion hypothesis assumes the elided VP is fully syntactically represented but deleted in the phonological component between SPELLOUT and PF. It suggests that VP deletion is the process that generates sloppy identities because co-indexation needs to occur with respect to binding conditions. Example

2.i) John will eat his apple, and Sam will [VPØ] too. 2.ii) [Johni will eat hisi apple] and [Samj will eat hisj apple].

Looking at example 2.i), VP deletion is why a null VP is derived. Before deletion, as seen in example 2.ii), the sentence would in fact be read as "John will eat his apple, and Sam will eat his apple too." The clauses [John will eat his apple] and [Sam will eat his apple] share an identical VP in the sense they have the same constituent structure, so the second clause can be deleted because it is identical to its antecedent VP. Now turning to coindexation, this sentence contains two constituents combined by the conjunction "and". The clauses are each independent complete sentence structures, so presumably each pronoun would co-index to its referent in its constituent to comply with binding theories. With this co-indexation, illustrated in example 2. ii), a sloppy reading is produced. However, when considering cases sensitive to binding theories, the expected strict reading of sentence 3) would violate the Binding Principle A. According to this principle, an anaphor must be bound in its binding domain, meaning it must be bound within the same clause as its referent.

3) John blamed himself and Bill blamed himself

Expected strict reading:

3.i) John i [VP blamed himselfi], and Billj [VP blamed himself i]

Expected sloppy reading:

3.ii) Johni [VP blamed himselfi], and Billj [VP blamed himselfj]

Taking this into consideration, it is observed that strict readings are difficult to be obtained in sentences like this, because if the anaphor himself in the elided VP is co-indexed with 'John' it would violate Binding Theory A because they are in separate clauses. C-command relationships are represented by colour coding in the syntax tree. As depicted in the tree diagram and illustrated in green, 'Johni' c-commands 'himselfi' in the first VP. 'Billj' on the other hand c-commands 'himselfj' in the second VP, colour coded in orange. Due to binding domains, the DPs closest to the anaphors have to be the ones they bind to and co-index with. Therefore, 'Johni' cannot not c-command the 'himselfj' in the second VP, as shown through the difference in colour coding. Consequently, Binding Theory A would be violated if the co-indexation of example 2.i) generates a strict reading. Hence, PF-deletion hypothesis generates sloppy readings because it treats the elided VP as identical structures to the antecedent VP and co-indexation is constrained by locality.

… excerpt ends here. Continue reading the full article.

Illustrations

Sloppy identity: Tree for the strict reading
Tree for the strict reading
Sloppy identity: Tree for the sloppy reading
Tree for the sloppy reading
Sloppy identity: Y Model
Y Model
Sloppy identity: Syntax Tree for sentence 3.ii)
Syntax Tree for sentence 3.ii)
Sloppy identity: Tree for Centering Theory's strict reading
Tree for Centering Theory's strict reading

Worked examples

Example 1 — a first encounter with Sloppy identity

Start with the simplest possible case. Write down what Sloppy identity claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In biology, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Sloppy identity before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Sloppy identity ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Sloppy identity

In research
Sloppy identity appears in biology research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Sloppy identity in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Sloppy identity is common in secondary-school and first-year university syllabi. It links to neighbouring topics Formal semantics (natural language), Generative syntax, Semantics, so understanding it makes those chapters shorter.
In everyday life
Look for Sloppy identity outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Sloppy identity in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Sloppy identity means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Sloppy identity out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Sloppy identity in simple terms?

In linguistics, sloppy identity is an interpretive property that is found with verb phrase ellipsis where the identity of the pronoun in an elided VP (verb phrase) is not identical to the antecedent VP. For example, English allows VPs to be elided, as in example (1).

Why does Sloppy identity matter?

Because it connects several biology ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Sloppy identity?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Sloppy identity.

Tags

  • Formal semantics (natural language)
  • Generative syntax
  • Semantics
  • Syntax

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