and on the other hand, reveal the influences of
financial and non-financial indicators on enterprises’
future development. By classifying the opinion
targets extracted from Web-financial reviews, the
financial and non-financial indicators in the reviews
can be obtained, and we call them the Web
financial indexes.
Being real-time, comprehensive, and in-depth, Web
financial reviews make possible comprehensiveness and
systematicness of financial and non-financial indicators
in enterprise financial early warning models. In addition,
the sentiment inclination of the reviews makes
possible quantification of Web financial indexes.
The extraction and sentimental quantification of Web
financial indexes based on Web financial reviews is a
meaningful, yet extraordinarily challenging project.
1) Extraction of opinion targets in Web financial
reviews and construction of Web financial indexes
The opinion targets refer to the objects modified
by the evaluative words. For example, the words
component, function and service of a product in
product reviews, and the words people, event and
subject of conversation in news commentaries are all
opinion targets. Groups of opinion targets constitute
topics, for example, the opinion targets in product
reviews can be classified into product group. In Web
financial reviews, opinion targets can be a national
policy, a sub-item in financial statements, or a
subject of conversation. The grouping of opinion
targets results in Web financial indexes. Now
available studies mostly focus on the extraction and
grouping of opinion targets in product reviews, and
by comparison, the extraction and classification of
opinion targets in Web financial reviews are much
more complicated because those reviews involve
wide range of areas.
(1) The opinion targets in product reviews are
generally nouns or noun phrases, such as 'Apple',
'screen' and 'keyboard layout' in a cellphone review.
In financial reviews, in addition to being nouns or
noun phrases such as 'raw material' and 'stock price',
opinion targets can also be subordinate clauses. For
example, in the sentence 'Share price rise quickly is
good.', the opinion target of the sentiment word
'good' is a verb phase ' share price rise quickly '.
Therefore, the extraction of opinion targets from
Web financial reviews is more complicated.
(2) In product reviews, opinion targets are more
evenly distributed. For instance, in a cellphone review,
the user would generally comment on the appearance,
audio, image display, etc. Financial reviews may
contain interpretation of financial statements,
deciphering of macro policies, and analysis of
personnel movement. The different numbers of
comments in different categories lead to very different
frequencies of opinion targets’ occurrence.
Consequently, the construction of Web financial
indexes based on opinion targets grouping is much
more complicated.
2) Quantification of Web financial indexes
In opinion target-based sentimental analysis, the
sentiment value of each opinion target is first
calculated based on the sentiment phrase, and then
the opinion target is classified into corresponding
topic/indicator based on the grouping of opinion
targets.
In product reviews, sentiment words are usually
adjectives, and available studies mostly perform
sentimental analysis based on adjective sentiment
words. Different from product reviews, Web financial
reviews contain sentiment words that have more
diverse parts of speech. Besides being adjective,
those sentiment words may be verb, adverb or noun,
especially verb. For example, in the previous example
‘Share price rise quickly is a good thing’, the word
‘rise’ is a verb sentiment word, and the phrase ‘good
thing’ is a noun sentiment word. The diversity of
sentiment words’ parts of speech in financial
reviews makes the identification of sentiment words
and the calculation of those words’ polarity and
intensity more difficult. In addition, this diversity
results in more flexible components the sentiment
words serve as in sentences, thus the sentiment
word-based extraction of opinion targets is also
more difficult.
The diversity of opinion targets’ composition,
differences in opinion targets’ frequencies, and
richness of sentiment words’ parts of speech in Web
financial reviews make the extraction of opinion
targets, the construction of Web financial indexes, as
well as the opinion target-based sentimental analysis
all more complicated, and bring new challenges to
natural language processing.
2 RELEVANT STUDIES
2.1 Relation between Web Financial
Reviews and Enterprises’ Financial
Statuses
The first research on Web financial reviews was
done by Wysocki (1999). After investigating the 50
listed companies that had the greatest amounts of
information during Jan 1998 to Aug 1998, Wysocki
noticed that with information from the notice board,
the trading volume and abnormal stock returns of
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