Open Journal of Modern Linguistics
2013. Vol.3, No.2, 101-107
Published Online June 2013 in SciRes (
Copyright © 2013 SciRes. 101
Survey of Common Errors of English to Vietnamese Google
Translator in Business Contract
Trn Lê Tâm Linh
Foreign Language Center, University of Science, Viet Nam National University, Hochiminh City, Vietnam
Received April 1st, 2013; revised May 2nd, 2013; accepted May 10th, 2013
Copyright © 2013 Trn Lê Tâm Linh. This is an open access article distributed under the Creative Commons
Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the
original work is properly cited.
Machine translation is a prolonged and difficult problem, but it becomes more and more attractive due to
its huge benefits for our society. Nowadays, Google Translator (GT) is one of the most common machine
translation softwares because of its relatively high accuracy. However, some language pairs with their
different typology and some specialized texts which are translated by GT have not issued really good
translation results yet. In this paper, we survey the common errors of machine translation from the point
of view of comparative linguistics in business contracts when these legal documents are translated from
English into Vietnamse by using GT. Hopefully, these results can be used to intend the effective ways
improving translation models of computer in the future.
Keywords: Machine Translation (MT); Lexical Error; Semantic Error; Word Order Error; Missing Error;
Redundant Errors; Google Translator
Since Vietnam has intergrated into World Trade Organisa-
tion, most of the global relationships such as commercial, im-
port, export transactions are involved in business contracts, so
these kinds of legal documents become more and more essen-
tial. As a result, drafting contracts considered the most vital.
For studying languages in the contracts, the role of translation
is remarkable. Nowadays, the volume of English-Vietnamese
bilingual contracts becomes so huge that hand-made translation
cannot catch up with the needs of booming information in
business. To solve this problem, machine translation can meet
the pressing and necessary requirements of business contract
translation. That is the main reason why we have studied about
common errors in English-Vietnamese business contracts trans-
lated by Google translation software.
Programs of machine translation (MT) for natural language
have been built since early 1950s, but their success has still
limited within pairs of languages which have nearly the same
grammar, structures as well as vocabulary such as English-
French, English-Russian... Among them, the kinds of scientific
or legal documents are translated remarkably successfully due
to their clear grammar and their simple single meaning. On the
other hand, pairs of completely differently typological lan-
guages which are translated by MT have translating results still
badly. For instance, because English belongs to an inflectional
language, but Vietnamese is a kind of isolating language. As a
result, there are too many errors in business contracts when
they are translated by MT from English into Vietnamese vice
versa. The main reason to carry out a survey of common errors
of machine translating is to find the methods correcting them.
These works need to combine between linguistists and profes-
sional computer experts because everything can be remedied if
its causes are found.
Related Works and General Aspects of Linguistics
There are many works which are related to studying machine
translation, contrastive languages and general aspects of lin-
guistics. For example, firstly, Error classification for MT eva-
luation was studied by Mary A. Flanagan. She presents a sys-
tem for classifying errors in MT output as a means of evalu-
ating output quality. Classification of errors provides a basis for
comparing translations produced by different machine trans-
lation (MT) systems and formalizes the process of error count-
ing. Error classification can provide a descriptive framework
that reveals relationships between errors. For example, if sub-
ject and verb do not agree in person or number, the error can be
classified as one of agreement, rather than an incorrect noun
inflection, or verb inflection or both. Error categorization can
also help the evaluator to map the extent of the effect in chains
of errors, allowing comparison among MT systems (Mary, 1996:
p. 66). Secondly, Evaluation of automatic translation output is
a difficult task. Several performance measures like Word Error
Rate, Position Independent Word Error Rate and the BLEU and
NIST scores are widely use and provide a useful tool for com-
paring different systems and to evaluate improvements within a
system. However the interpretation of all of these measures is
not at all clear, and the identification of the most prominent
source of errors in a given system using these measures alone is
not possible.Therefore some analysis of the generated transla-
tions is needed in order to identify the main problems and to
focus the research efforts. This area is however mostly unex-
plored and few works have dealt with it until now. In this paper
we will present a framework for classification of the errors of a
machine translation system and we will carry out an error
analysis of the system used by the RWTH in the first TC-STAR
evaluation (David, 2006: p. 1). Thirdly, machine translation
evaluation is a difficult task, since there is not only one correct
translation of a sentence, but many equally good translation
options. Often, machine translation systems are only evaluated
quantitatively, e.g. by the use of automatic metrics, which is
fast and cheap, but does not give any indication of the specific
problems of a MT system. Besides, Error analysis of statistical
machine translation output has been researched by David Vilar,
Jia Xu, Luis Fernando D’Haro, and Hermann Ney (David,
2006). Fourthly, Association for Computational Linguistics has
said that some analysis of the generated output is needed in
order to identify the main problems and to focus the research
efforts. On the other hand, human evaluation is a time consum-
ing and expensive task. In their paper, they investigate methods
for using of morpho-syntactic information for automatic eva-
luation: standard error measures WER and PER are calculated
on distinct word classes and forms in order to get a better idea
about the nature of translation errors and possibilities for im-
provements (Maja, 2006: p. 1). Fifthly, according to Morpho-
syntactic information for automatic error analysis of statistical
machine translation output from proceedings of the workshop
on statistical machine translation (Maja June, 2006, New York
City, pages 1-6). Sixthly, Word error rates: decomposition over
POS classes and applications for error analysis has been said
that the obtained results are shown to correspond to the results
of a human error analysis. The results obtained on the European
Parliament Plenary Session corpus in Spanish and English give
a better overview of the nature of translation errors as well as
ideas of where to put efforts for possible improvementsvof the
translation system (Maja, 2007: p. 47). Seventhly, a prelimi-
nary study of the length of sentence in legal English (Duong,
2008). Eighthly, there are many works of studying contrastive lan-
guages in contracts as well as law documents such as editing
techniques of law normative act and legal languages (Nguyen,
2010). Tenthly, there are many successful works for errors of
machine translation such as A tool for error analysis of ma-
chine translation output, according to Sara S. (2011).
Besides, there should be various ideas to study languages in
these kinds of law documents to helps those who use contracts
to avoid misunderstanding ambiguous words which can cause
problems due to them. Whenever the quality of translation is
said, its common errors will be interested most because they
can cause any serious problems without finding and correcting
in time. So, there should be the discriminating criterion of com-
mon errors in order to suggest the ways to correct them.
On analysing any errors of any languages, reseachers should
find them belonging to grammatical errors, lexical meaning er-
rors or pragmatical errors. In this paper, we survey the com-
mon errors of machine translation from the point of view of
comparative linguistics in business contracts when these legal
documents are translated from English into Vietnamse by using
GT. Hopefully, these results can be used to intend the effective
ways improving translation models of computer in the future.
Software Supports to Research
Introduction of Blast Software
Blast (the Bi-Lingual Annotator/Annotation/Analysis Support
Tool) is an error annotation tool for machine translation output.
It came from a Swedish author, Sara Stymne, Linköping Uni-
versity, Linköping, Sweden.
Blast, which is considered as a tool for error analysis of ma-
chine translation output, can aid the user by highlighting simi-
larities with a reference sentence. Blast is flexible in that it can
be used with output from any MT system, and with any hierar-
chical error typology. It has a modular design, allowing easy
extension with new modules. To the best of our knowledge,
there is no other publicly available tool for MT error annotation.
Since we believe that error analysis is a vital complement to MT
evaluation, we think that Blast can be useful for many other MT
researchers and developers. 2 MT Evaluation and Error Analysis
Hovy et al. (2002) discussed the complexity of MT evaluation,
and stressed the importance of adjusting evaluation to the pur-
pose and context of the translation. However, MT is very often
only evaluated quantitatively using a single metric, especially in
research papers. Quantitative evaluations can be automatic,
using metrics such as Bleu (Papineni et al., 2002) or Meteor
(Denkowski & Lavie, 2010), where the MT output is compared
to one or more human reference translations.Besides, Blast is
also aaccepted to the Association for Computational Linguistics
(ACL’11), demonstration session. Portland, Oregon, USA. July
Application of Blast into Analyzing Vietnamese Common
Machine Translation Errors
The material is studied for this paper is “Legal documents on
labour and economic contracts, settlement of labour and eco-
nomic disputes (Vietnamese-English)” [18]. This bilingual book
concludes 733 pages. After typing the whole books, we ex-
tracted 2947 language pairs of English and Vietnamse. Then
they are processed by our special software to delete the repea-
ted language pairs. As a result, there are 2068 remaining pairs
to survey.
Blast has three different working modes: annotation, edit and
search. The main mode is annotation, which allows the user to
add new error annotations. The edit mode allows the user to
edit and remove error annotations. The search mode allows the
user to search for errors of different types. It can also create
support annotations, that can later be updated by the user, and
calculate and print statistics of an annotation project.
From Figure 1, we can see a screenshot of Blast. The MT
output is shown to the annotator one segment at a time, in the
upper part of the screen. A segment normally consists of a sen-
tence and the MT output (Vietnamese) can be accompanied by
a source sentence (English), a reference sentence (Vietnamese),
or both. Error annotations are marked in the segments by bold,
underlined, colored text, and support annotations are marked by
light background colors. The bottom part of the tool, contains
the error typology, and controls for updating annotations and
navigation. The error typology is shown using a menu structure,
where submenus are activated by the user clicking on higher
Results for Error Analysis of Blast on Machine
Translation Output
Overall Results
There are total 2068 language pairs containing about 60,017
words. The data have 4529 errors processing. As a result, the
Copyright © 2013 SciRes.
Copyright © 2013 SciRes. 103
Figure 1.
Example of blast model.
average error per sentence is 2.97, but the average error per
sentence with errors is 3.015. Besides, it also shows the average
length of a sentence is 13.252 words (Table 1).
of errors such as errors extra word errors (E), missing word
errors (M), wrong word order (O) and incorrect word (W). The
results of these including incorrect words (W) have the most
error rate which is 58.40% with 2645 errors; wrong word order
has the lowest rate including 504 errors occupying 11.13%;
whereas missing errors having a little higher rate is 11.70%
with 530 errors; and the second highest occupying 18.77% with
850 errors (Figure 2).
Number of Sentences with a Certain Number of
The results for 2068 sentences (S) with a certain number of
errors (E) illustrate that the best result from this table is 566 of
2068 sencences keeping their meanings in the context. On the
other hand, the maximum errors per sentence is 13, but there
are only 5 sentences in this case. There are 431 sentences hav-
ing 1 error; 322 sentences containing 2 errors; 272 sentences
with 3 errors; 161 sentences with 4 errors; 135 sentences with 5
errors; 81 sentences with 6 errors; 34 sentences with 7 errors;
30 sentences with 8 errors; 19 sentences with 9 errors; 7 sen-
tences with 10 errors; and 2 sentences having 11 or 12 errors
(Table 2).
Cross Classifi cations
Based on cross classifications, there are three of four ranges
of errors considerable because they still remain good context
meanings with levels of adequacy, fluency, and both of them
(Figure 3).
Results and number of errors for cross classifications, but
their context meanings are acceptable. The adequacy has the
highest rate with 524 errors (11.57% of total number identified
errors); the fluency has unremarkble with only 0.02%; whereas
there are 9 errors, but they still remain both adequacy and flu-
ency level.
Main Classification
According to main classification, there are 4 basic categories
All Classifications
Table 1.
Table of result from blast. All classifications mean that there are 4 basic categories of
errors including (M), (E), (O) and (W), each of which has sub-
categories such as orthographical, form, syntax, sense, style,
untranslated and extra-translated errors following.
Number of sentences: 2068
Number of words: 60,017
Number of errors: 4529
Average error per sentence: 2.97
Average error per sentence with errors: 3.015
Average of words per sentence: 13.252 Missing Words: 530 Errors (Approximately 11.7%)
There are 2 types of lack of words to make errors such as
content missing and grammar missing, each of which also di-
vided into 2 sub-types. Although they are considered errors,
they don’t affect their meanings in the context. According to
the diagram there are 11 errors of content missing (M-cont-ade
= 0.24%) and 5 ones of grammar missing (M-gram-ade =
0.11%) keeping good meanings like human translation. On the
other hand, 350 errors of content missing (M-cont-neither =
7.73% ) and 69 errors of grammar missing (M-gram-neither =
1.52%), which create bad MT sentences (Figu re 4 ).
Table 2.
Number of errors per sentence.
0 1 2 3 4 5
(E) 6
566 431 322 273 161 135 81
7 8 9 10 11 12 13
34 30 19 7 2 2
(S) 5
530 504
18.77% 11.70% 11.13% 58.40%
Figure 2.
Results for the four common categories of errors.
11.57% 0.20%0.02%
Figure 3.
Result of cross classification.
Figure 4.
Errors of missing words.
Extra Words (Or Redundant Error s): 850 Err or s (About
This figure shows that there are 850 errors of the extra word
category divided into 6 sub-categories. The first ones are con-
sidered errors, but they still remain adequate (E-cont-ade =
0.29%), fluent (E-gram-fl = 0.02%), even both adequate and
fluent (E-gram-both = 0.02%) or extra grammar words (E-
gram-ade = 0.22%) meanings in the context, which means that
these MT output are acceptable. On the contrary, the other ones
are real errors causing big problems for MT. For example, there
are 433 errors due to machine translating extra words (E-cont-
neither = 9.56% of total errors) to create redundant meanings
compared to source sentences; and 235 errors (E-gram-neither
= 5.19%) translated by MT in the wrong grammar aspect (Fig-
ure 5).
Figure 5.
Errors of extra words.
Figure 6.
Word order errors.
Wrong Word Order: 504 Errors (Approximately 11.13%)
This category contains wrong word order, but they are di-
vided into 7 sub-categories (instead of 8 ones). There are 38
phrases are errors of word orders in the long distance (p-long-
ade = 0.84%) and 15 phrases are errors of word orders in the
short distance (p-short-ade = 0.33%) , but both of them still have
good meanings in the context. By contrast, 277 phrases are
errors of word orders in the long distance (p-long-neither =
6.12%) and 51 phrases are errors of word orders in the short
distance (p-short-neither = 1.13%), which are really errors to
make the bad results for MT (Figure 6).
Besides, the same situation also happens when there are 2
cases for single word order error in the short distance that the
first one contains 2 errors (w-short-ade = 0.04%) but it still re-
mains meanings in the context; and the other includes 8 errors
(w-short-neither = 0.18%) with complely wrong meanings;
finally, single word order errors in the long distance with com-
plely wrong meanings have 18 errors (w-long-neither =
Copyright © 2013 SciRes.
The Other Incorrect Words: 2.645 Errors (About 58.4%)
This category is named as incorrect/wrong words (W) which
have sub-categories such as orthographical, form, syntax, sense,
style, un-translated and extra-translated errors.
1) Orthographical errors belonging to lexical meanings: 216
errors (4.77%)
Errors belong to orthographical ones including punctuation
(punct), capialization (casing), number formating (number) and
the others (other). Among these errors, punctuation errors have
the highest rate with 70 errors, 54 of which (1.19%) create
wrong meanings (W-orth-punct-neither), but the 16 other errors
don’t make those sentences have wrong meanings (W-orth-
punct-ade). Then, the second highest rate is capitalization ones
with 89 errors (1.96%) in which 39 words are really errors (W-
orth-casing-neither), but other 50 errors still remain their mean-
ings in the context (W-orth-casing-ade). Besides, the number
formating errors also have the same result such as adequate
meanings (W-orth-number-ade) in the context (0.13%) and real
errors without suitable meanings with the source language (W-
orth-number-neither). Moreover, we have named the other er-
rors (W-orth-other-neither) because sometimes the source sen-
tences typed wrong spelling ( for example: Instead of typing
“price”, “prince” is typed with the meaning completely wrong),
the other case such as wrong spelling in the MT sentences (Fi-
gure 7).
2) Form and style errors belonging to pragmatical meanings:
423 errors (9.34%)
Results for errors of style and form, which belong to prag-
matical meanings. Firstly, there are 197 errors of style (W-
style-ade = 3.95%), but they still good meanings in the context.
Moreover, 3 errors of style have fluent and adequate meanings
(W-style-both = 0.07%). On the other hand, the 134 others of
style lead to wrong meanings (W-style-neither = 2.96%). Sec-
ondly, the form errors divided into 4 sub-categories such as
agreement (Incorrect agreement between subject-verb, noun-
adjective, past participle agreement with preceding direct object,
etc.), co-reference, source mismatch, and “other” which is
signed (W-form-other-ade) or (W-form-other-ade). Although
these form errors have an unmarkable rate, they also show us
the detailly various errors of MT. As a result, there are the only
Figure 7.
Orthographical errors.
one agreement form errors with adequate meaning (W-form-
agree-ade = 0.02%), 3 agreement form errors with wrong mea-
nings (W-form-agree-neither = 0.07%), 2 co-reference form er-
rors with their wrong meanings (W-form-coref-neither =
0.04%), 8 source mismatch form errors with their adequate
meanings (W-form-mismatch-ade = 8%), 17 source mismatch
form errors with their wrong meanings (W-formmismatch- nei-
ther = 0.38%), and wrong form of target/system sentences (W-
form-other-neither = 0.15%) (Figure 8).
3) Sense errors belong to semantic meanings: 1718 errors
Especially, there are 156 errors of business contract terms
which are chosen common entries of dictionaries but they still
remain adequate meanings in the context (W-sense-term-ade =
3.44%) and 5 others having both fluent and adequate meanings
(W-sense-term-both = 0.11%). Moreover, there are some kinds
of sense errors in this diagram having good meanings in the
context such as errors of disambiguation due to chosen wrong
entries by MT (W-sense-dis-ade = 0.18%), 2 non-idiomatic
sense errors (W-sense-nondiom-ade = 0.04%). On the other
hand, the most errors in this diagram are 176 errors of disam-
biguation sense with wrong meanings (W-sense-dis-neither =
3.89%). Besides, GT cannot translate idiom, non-idiomatic words
well, and they become common errors (such as W-sense-
idiom-neither = 0.04% and W-sense-nondiom-neither = 0.09%)
(Figure 9).
4) Syntax errors, extra-translated and un-translated errors:
287 errors (6.24%)
This diagram shows that errors of syntagmatic meanings
which belong to a range of clause (W-syntax-clause-neither =
0.09%), wrong function (W-syntax-function-neither = 0.46%),
disambiguation because of wrong part of speech (W-syntax-
pos-neither = 0.49%), errors due to MT output having extra
words compared to source language but unchanging meaning in
the context (W-syntax-exTrans-ade = 0.02%), and the highest
rate of errors due to keeping the same foreign language of source
sentence (W-syntax-foreign-neither = 5.26% with 238 errors)
(Figure 10).
According to the criteria of identifying errors above, they can
be divided into 4 basic categories of machine translation errors
such as missing words (M), redundant/extra words (E), wrong
word order (O), and incorrect words (W). In this paper, we only
survey the common errors of machine translation from the point
of view of comparative linguistics in business contracts when
these legal documents are translated from English into Viet-
namse by using Google Translator owing to the Blast software
which analyzes them automatically and systematically in order
to find an effective way to study more deeply. Hopefully, the
next papers, we will describe more detailly about all kinds of
MT errors such as finding them, describing them, explaining
them, categorizing them, evaluating them, and suggesting latest
trends to improve English-Vietnamese machine translation the
most effectively.
In summary, the results of this study showed several im-
portant tihings about machine translation in Vietnam. First, ma-
chine translation has not given the good results yet. Then,
Copyright © 2013 SciRes. 105
Copyright © 2013 SciRes.
Figure 8.
Errors of form and style.
Figure 9.
Semantic errors.
Figure 10.
Syntax errors, extra-translated and un-translated errors.
there are too little studying about machine translating from
English into Vietnamse in general as well as business contracts.
A part of this reason is that most of machine translation software
using the method of statistical machine translation which re-
quires the more bilingual corpus there are, the more exact re-
sults are given. However, to build a kind of corpus in English-
Vietnamse costs too much. So, this problem becomes more and
more difficult. On the other hand, although statistical machine
translation has been confirmed its strenght due to a huge corpus,
its results are still suspected because there are too many errors
after translating. So, there should have been the works studying
more deeply for this field. It is important that linguistists and
computer programmers coordinate more closely to find solu-
tions in order to limit those common errors.
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