---
title: "Parse Fitting and Prose Fixing: Getting a Hold on Ill-Formedness"
description: "A hand-written grammar can never cover all real text. 13 references, cited by 15 papers here."
authors: ["K. Jensen", "G. E. Heidorn", "L. A. Miller", "Y. Ravin"]
year: 1983
venue: "Computational Linguistics"
source: "https://aclanthology.org/J83-3002/"
licence: "CC BY-NC-SA 3.0 (ACL Anthology, before 2016)"
licence_url: "https://creativecommons.org/licenses/by-nc-sa/3.0/"
summary_licence: "Elamur Cosmic License"
canonical: "https://research.elamur.ai/free/en/papers/jensen-1983-parse-fitting-prose-fixing-getting/"
---
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# Parse Fitting and Prose Fixing: Getting a Hold on Ill-Formedness

**Authors:** [K. Jensen](https://md.research.elamur.ai/free/en/authors/karen-jensen/), G. E. Heidorn, L. A. Miller and Y. Ravin · **Year:** 1983 · **Venue:** [Computational Linguistics](https://md.research.elamur.ai/free/en/venues/cl/) ([Computational Linguistics 1983](https://md.research.elamur.ai/free/en/venues/cl/1983/)) · **Licence:** [CC BY-NC-SA 3.0 (ACL Anthology, before 2016)](https://creativecommons.org/licenses/by-nc-sa/3.0/)

**Links:** [Publisher's page](https://aclanthology.org/J83-3002/) · [PDF](https://aclanthology.org/J83-3002.pdf) · [OpenAlex](https://openalex.org/W1960020614)

**Citations:** 80 citations (OpenAlex, 2026-10-14) · [15](https://md.research.elamur.ai/free/en/papers/jensen-1983-parse-fitting-prose-fixing-getting/cited-by/) in our library, of the 149,439 papers whose bibliographies we read

## Summary
A hand-written grammar can never cover all real text. Yet a grammar and style checker needs some structure for every input, including fragments, elliptical sentences, odd punctuation and plain errors. The authors address this within IBM's EPISTLE system, which critiques business English. They split parsing into three parts: a core grammar of about 300 augmented phrase structure rules written in NLP, a metric that ranks competing parses, and a fallback "fitting" step for inputs the core rejects. If bottom-up parsing ends without a sentence node spanning the whole string, fitting reuses the partial constituents already built. It picks a head, preferring tensed VPs with subjects, and attaches the leftover pieces on either side. The resulting approximate tree lets error detection and style critique continue where a conventional parser would stop. The paper also shows cases where a fitted tree leads to wrong diagnoses. It argues that fitting copes better than rule relaxation with the practically unlimited variety of ill-formed input.

## Key points
- The grammar is written in NLP (Heidorn 1972), implemented in LISP/370, and uses only syntactic information. It draws on an online dictionary of about 130,000 entries.
- The test base is 2254 sentences from 411 real business letters. The average length is 19.2 words and the longest sentence has 63 words.
- The core grammar gives a single approximate parse for almost 70% of input and a few alternative parses for another 16%. Fitting covers the remaining failures.
- Head selection follows a fixed preference order: tensed VPs with a subject, tensed VPs without one, verbless phrases (NPs, PPs), non-finite VPs, then everything else. Ties go to the widest candidate, then the leftmost, then the best parse-metric score.
- The closest related work is Slocum's "shortest path" phrasal analysis in the LRC Machine Translation System. The paper contrasts fitting with relaxation methods from Kwasny and Sondheimer, Weischedel et al., and Hayes and Mouradian.

*Our summary of the paper, in our own words — not its text. The work belongs to its authors; read it at the links above.*

## Institutions

- [IBM Research - Thomas J. Watson Research Center](https://md.research.elamur.ai/free/en/labs/ibm-research-thomas-j-watson-research-center/) — Research institute, Yorktown Heights, United States · 53 works · 49,193 citations

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## Cite

Cite as: K. Jensen, G. E. Heidorn, L. A. Miller and Y. Ravin. 1983. Parse Fitting and Prose Fixing: Getting a Hold on Ill-Formedness. Computational Linguistics.

The paper itself, not this page. BibTeX from the library's record of the work.

```bibtex
@article{jensen1983parse,
  title = {{Parse Fitting and Prose Fixing: Getting a Hold on Ill-Formedness}},
  author = {K. Jensen, G. E. Heidorn, L. A. Miller and Y. Ravin},
  journal = {Computational Linguistics},
  year = {1983},
  url = {https://aclanthology.org/J83-3002/}
}
```

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## References

13 references, 1 of them with a card of ours. ↗ leads to the work, «find» searches for one we have no id for yet.

1. Hayes, P.J. and Mouradian, G.V. 1 9 8 1 Flexible Parsing. Am. J. Comp. Ling. 7(4): 232-242. [find](https://scholar.google.com/scholar?q=Hayes%2C+P%2EJ%2E+and+Mouradian%2C+G%2EV%2E+1+9+8+1+Flexible+Parsing%2E+Am%2E+J%2E+Comp%2E+Ling%2E+7%284%29%3A+232%2D242%2E)
2. Heidorn, G.E. 1972 Natural Language Inputs to a Simulation Programming System. Technical Report NPS-55HD72101A. Monterey, California: Naval Postgraduate School. [find](https://scholar.google.com/scholar?q=Heidorn%2C+G%2EE%2E+1972+Natural+Language+Inputs+to+a+Simulation+Programming+System%2E+Technical+Report+NPS%2D55HD72101A%2E+Monterey%2C+California%3A+Naval+Postgraduate+School%2E)
3. Heidorn, G.E. 1982 Experience with an Easily Computed Metric for Ranking Alternative Parses. Proc. 20th Annual Meeting of the ACL. Toronto, Canada: 82-84. [find](https://scholar.google.com/scholar?q=Heidorn%2C+G%2EE%2E+1982+Experience+with+an+Easily+Computed+Metric+for+Ranking+Alternative+Parses%2E+Proc%2E+20th+Annual+Meeting+of+the+ACL%2E+Toronto%2C+Canada%3A+82%2D84%2E)
4. Heidorn, G.E.; Jensen, K.; Miller, L.A.; Byrd, R.J.; and Chodorow, M.S. 1982 The EPISTLE Text-Critiquing System. I B M Systems Journal 21(3): 305-326. [find](https://scholar.google.com/scholar?q=Heidorn%2C+G%2EE%2E%3B+Jensen%2C+K%2E%3B+Miller%2C+L%2EA%2E%3B+Byrd%2C+R%2EJ%2E%3B+and+Chodorow%2C+M%2ES%2E+1982+The+EPISTLE+Text%2DCritiquing+System%2E+I+B+M+Systems+Journal+21%283%29%3A+305%2D326%2E)
5. Jensen, K. and Heidorn, G.E. 1983 The Fitted Parse: 100% Parsing Capability in a Syntactic Grammar of English. Proc. Conf. on Applied Natural Language Processing. Santa Monica, California: 93-98. [find](https://scholar.google.com/scholar?q=Jensen%2C+K%2E+and+Heidorn%2C+G%2EE%2E+1983+The+Fitted+Parse%3A+100%25+Parsing+Capability+in+a+Syntactic+Grammar+of+English%2E+Proc%2E+Conf%2E+on+Applied+Natural+Language+Processing%2E+Santa+Monica%2C+California%3A+93%2D98%2E)
6. Kwasny, S.C. and Sondheimer, N.K. 1981 Relaxation Techniques for Parsing Ill-Formed Input. Am. J. Comp. Ling. 7(2): 99-108. [find](https://scholar.google.com/scholar?q=Kwasny%2C+S%2EC%2E+and+Sondheimer%2C+N%2EK%2E+1981+Relaxation+Techniques+for+Parsing+Ill%2DFormed+Input%2E+Am%2E+J%2E+Comp%2E+Ling%2E+7%282%29%3A+99%2D108%2E)
7. Lasnik, H. and Freidin, R. 1 9 8 1 Core Grammar, Case Theory, and Markedness. Proc. 1979 G L O W Conf. Pisa, Italy. [find](https://scholar.google.com/scholar?q=Lasnik%2C+H%2E+and+Freidin%2C+R%2E+1+9+8+1+Core+Grammar%2C+Case+Theory%2C+and+Markedness%2E+Proc%2E+1979+G+L+O+W+Conf%2E+Pisa%2C+Italy%2E)
8. Miller, L.A.; Heidorn, G.E; and Jensen, K. 1981 Text-Critiquing with the E P I S T L E System: An Authors's Aid to Better Syntax. A F I P S Conf. Proc., Vol. 50. Arlington, Virginia: 649-655. [find](https://scholar.google.com/scholar?q=Miller%2C+L%2EA%2E%3B+Heidorn%2C+G%2EE%3B+and+Jensen%2C+K%2E+1981+Text%2DCritiquing+with+the+E+P+I+S+T+L+E+System%3A+An+Authors%27s+Aid+to+Better+Syntax%2E+A+F+I+P+S+Conf%2E+Proc%2E%2C+Vol%2E+50%2E+Arlington%2C+Virginia%3A+649%2D655%2E)
9. Slocum, Jonathan. 1983 A Status Report on the LRC Machine Translation System. Proc. Conf. on Applied Natural Language Processing. Santa Monica, California: 166-173. [find](https://scholar.google.com/scholar?q=Slocum%2C+Jonathan%2E+1983+A+Status+Report+on+the+LRC+Machine+Translation+System%2E+Proc%2E+Conf%2E+on+Applied+Natural+Language+Processing%2E+Santa+Monica%2C+California%3A+166%2D173%2E)
10. Weischedel, R.M. and Black, J.E. 1980 [Responding Intelligently to Unparsable Inputs](https://md.research.elamur.ai/free/en/papers/weischedel-1980-responding-intelligently-unparsable-inputs/). Am. J. Comp. Ling. 6(2): 97-109.
11. Weischedel, R.M. and Sondheimer, N.K. 1981 A Framework for Processing Ill-Formed Input. Research Report. University of Delaware. [find](https://scholar.google.com/scholar?q=Weischedel%2C+R%2EM%2E+and+Sondheimer%2C+N%2EK%2E+1981+A+Framework+for+Processing+Ill%2DFormed+Input%2E+Research+Report%2E+University+of+Delaware%2E)
12. Weischedel, R.M. and Sondheimer, N.K. 1982 An Improved Heuristic for Ellipsis Processing. Proc. 20th Annual Meeting o f the ACL. Toronto, Canada: 85-88. [find](https://scholar.google.com/scholar?q=Weischedel%2C+R%2EM%2E+and+Sondheimer%2C+N%2EK%2E+1982+An+Improved+Heuristic+for+Ellipsis+Processing%2E+Proc%2E+20th+Annual+Meeting+o+f+the+ACL%2E+Toronto%2C+Canada%3A+85%2D88%2E)
13. Wilks, Yorick 1975 An Intelligent Analyzer and Understander of English. Comm. A C M 18(5): 264-274. [find](https://scholar.google.com/scholar?q=Wilks%2C+Yorick+1975+An+Intelligent+Analyzer+and+Understander+of+English%2E+Comm%2E+A+C+M+18%285%29%3A+264%2D274%2E)

*Updated 30 October 2026*