Constructing English Reading Courseware
Masao Utiyama (NICT)
Midori Tanimura (Kinki Univ.)
Hitoshi Isahara (NICT)
Contents• Goal and motivation• Courseware constructed• Construction algorithm• Experiment• Conclustion

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Goal
English reading courseware ← target corpus + vocabularyMotivation• Help students acquire target vocabulary• Help teachers create courseware
Benefit
ESP (English for Special Purposes)

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Courseware constructedVocabulary: TOEIC (Test of English for International Communication) +Corpus: The Daily Yomiuri newspaper articles→Courseware:• 116 articles• All of the TOEIC vocabulary• Distribution of the vocabulary was quite dense3

Example article

4Efficient courseware
Operational definition of efficiency• As short as possible• Contains the required vocabularyEffects• Exposes students the target vocabulary• Enable students to learn words in contexts through reading

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Optimization: Converting definition into algorithmĈ = arg minC Length(C)• C is courseware• C is a subset of the target corpus• C contains all of the target vocabulary• Ĉ is the minimum length courseware

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Greedy methodTo construct the minimum length courseware• Step1: Get a document with the maximum number of new words• Step2: Put it into the courseware• Step3: Until the courseware covers all of the target vocabulary7Document score (1/2)
Score(d|α, Vtodo, Vdone) = αg(d|Vtodo) + (1 − α)g(d|Vdone)• Both uncovered (Vtodo) and covered (Vdone) vocabulary• Uncovered vocabulary has priority over covered vocabulary
α=|Vdone|
1 + |Vdone|

8Document score (2/2)
g(d|V ) =k1 + 1|W (d) ∩ V |,|W (d)|k1((1 − b) + b E(|W (·)|) ) + 1• Based on the Okapi BM25 function (information retrieval measure)• Documents relevant to the target vocabulary• Large when many words are shared due to |W (d) ∩ V ||W (d)|• Large when the document length is short due to E(|W(·)|)

Effects
Short courseware that covers the target vocabulary9Experiment• TOEIC vocabulary• The Daily Yomiuri newspaper article corpus• Statistics of the constructed courseware• Problems• Use in the classroom

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Vocabulary: TOEIC• compiled by Chujo 2003 (publicly available)• 640 entries• beginner to intermediate level

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Corpus: The Daily Yomiuri• 25,000 articles• 300 words or less
• Japanese counterparts exist• lemmatized to match with the vocabulary

12Efficiency comparison with randomly sampled articles
Coursware = 20,900 tokens, 116 articles.
randomcourseware summary
average SD
avg. num. of common tokens
19.3 1.1
25.3 large
avg. num. of common types
12.8 0.6
17.4 large
coverage
0.616 0.016
1.0highConstructed courseware was efficient.

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Distribution of the number of types
45num. of new types
num. of common types
4035

num. of types

3025201510500204060
article ranking
1480

100120Increase in the number of covered types
0num. of tokens
10000

5000

15000

20000

700

600

num. of types

500

400

300

200

100
90%
50%
00204060
article ranking
1580

100120Problems: Usage discrepancies
agencyTOEIC → a business that provides particular services, (an advertisingagency)
Yomiuri → an administrative unit of government
appointment
TOEIC → a meeting arranged in advance
Yomiuri → the act of putting a person into a non-elective position

Remedy for the mismatches• Use a corpus that is similar to the TOEIC vocabulary• Best is the use of the TOEIC tests.

16Use in the classroom (1/2)• 3 English classes in one university since May 2004
• Beginner to intermediate level• Supporting material• Vocabulary quiz17

Use in the classroom (2/2)
Suitable to intermediate level students
Motivation is high.
• Vocabulary quiz:High scores• Meaning in contexts:
Takashi Kitaoka, president of Mitsubishi Electric Corp., said...
• Get used to reading:
The main textbook has become easy to read.
Promising, though detailed evaluation has yet to be done.

18Conclusion• Efficient Courseware ← Corpus + Vocabulary• Optimization with respect to efficiency• Promising

Future work
• Detailed evaluation• Acquisition of phrases

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