A Comparative Studyof Machine Translation and Computer Aided Translation〔＊〕

Li Qingzhao

（College of Foreign Languages Suzhou University，Suzhou Anhui 234000）

Ⅰ.Introduction

Globalization makes the translation market to expand，and the progress of science and technology enhances the development of translation methods and technology.More and more translators start to focus on translation speed as well as translation theory and quality.

Statistics show that artificial translation output for average is 2000 words per person per 8 hours；however，translation system can do 3000 characters per second.Computer translation system can complete 86400000 words in the same 8 hours，which is 43200 times as fast as artificial translation.〔1〕Thus，with the help of computer translation，translators can save time and effort.Computer technology continuously improves the translation speed and efficiency，which will help to win the fierce competition and meet the international needs in the translation quality and speed.

There are two kinds of computer translation：Machine Translation （MT）and Computer Aided Translation（CAT）.Closely connected，they partially improve translators’work efficiency，but it still has a long way to go.

Ⅱ.Definitions of MT and CAT

The concept of Computer Aided Translation （CAT）is different from Machine Translation （MT）.In 2002，Bowker said that“the main difference between MT and CAT is that who has actually done the real work of translation.”〔2〕

European Association of Machine Translation defined Machine Translation as：“the process of using computer to translate a natural source language into another natural target language.In general，it refers to sentences and full text translation of a natural language.”The whole process of translation has been completed all by computer without artificial participation，including analyzing structures of a source language，and the conversion of corresponding vocabulary and structures to a target language.But Machine Translation recognize grammar automatically，and then invokes the stored corpus to get one corresponding translation automatically，so when the grammar，vocabulary and syntax changes or get irregular，the context is changed，there will inevitably be errors.

According to scholar Amparo，CAT is the study of how to design or apply methods，tools and resources to help translators doing better.It can contribute to completing the translation work as well as the research and teaching activities.CAT is using translation software to aid translators in the process of language conversion.In short，the computer is no longer the only protagonist of the translating process，and translators are involved in the whole translation process，which play a very important role in MT.It is similar to the computer aided design （CAD），which actual plays an additional role of translation.It doesn’t depend on computer automatic translation to match the source language texts to the final translation results by software processing，but by making full use of database functions and translation memory（TM）to provide reference to translators.It is translators who determine the most appropriate translation in the end.Compared with artificial translation and Machine Translation，CAT can offer better translation quality and higher efficiency.

Ⅲ.The developmentandlimitationsof MT

1.The Development of MT

Due to its high cost and slow speed，the traditional manual translation failed to meet the needs of translation market，and Machine Translation emerges.

French scientist G.B.Artsouni first put forward the idea of Machine Translation.The ancestor of the modern MT was Soviet scientist Troianski，who gave detailed steps to realize MT in1933，and designed a prototype by mechanical principles of translation work.In 1954，America Georgetown Universi ty and International Business Machines Corporation （IBM）first carried joint experiments using computer machine translation system，which realized the first translation system beyond the word to word concept，marking the birth of the real Machine Translation system.MT flourished temporarily.

But in 1966，American Automatic Language Processing Advisory Committee（ALPAC）gave a negative attitude in a Machine Translation report on Machine Translation，which made Machine Translation entered into a recession period until late in 1970s.Studies on Machine Translation in China can be traced back to the early 1950s.After a period of setback，it became more prosperous since 1970s.In1987 Chinese Academy of Military Science developed“Keyi No.1”which marked the first Chinese MT system coming into being.In 1992，the Chinese Academy of Sciences Institute of Computer developed“863 intelligent English－Chinese translation system”.〔3〕

Since then，with the popularization and development of computer，many translation systems appeared，such as translation software“Tongyi”of Tianjin Datong Software Research Institute，“Transtar”of China Software Company and “Gaoyi”of Chinese Academy of Sciences Institute of Language，online translation software such as“Google online”，“Youdao online”，“Baidu”，“Iciba”，and translation dictionary tools such as PowerWord，Youdao Dictionary，Babylon，Orient Express，KingsoftFast.After decades of development，Machine Translation is developed from rule－based to corpus－based，and the vast corpus including statistics and examples makes the translation quality and efficiency improved significantly.

2.The Limitations of MT

Natural language is complex and flexible，but MT cannot be completely intelligent because computers have no cognitive and comprehensive ability as man.It is very difficult for MT to match the appropriate contexts reflected in the target languages.So in many cases，the results of MT are of poor quality，and manual check and translation is needed.

Ⅳ.Advantages of CAT

1.The Core Technology of CAT－TM

The development of computer technology makes corpus linguistics developing rapidly.As an important application field of corpus technology，MT technology，for average users，and CAT technology，for professional translators，have developed dramatically in recent years.〔4〕

CAT software in recent years becomes quite popular translators.CAT is regarded as an updating of MT.The current popular CAT software mainly takes Translation Memory（TM）as the core technology.“Translation Memory（TM）is a kind of strategy for translators to use computer program in the translation process”.〔5〕

The principle is：at the same time in the translation，CAT is establishing language database in the background，searching and matching by using artificial intelli－gence，and text content will be stored by using TM programs and database corpus.In the process of translation，when there are similar or duplicate terms，phrases，sentence，paragraphs，the system can automatically search，compare and provide translators with the most similar translation in memory，and then，man decide whether to accept or reject the use.After examination，the translation can be generated automatically，which means that the translators do not need to repeat reviewing the same sentences.Actually TM provides translation suggestions which contribute to the improvement of the efficiency and quality of translation as well as free time for translators.

Terminology Database （TD）technology is another form of TM.But unlike TM，the term mainly plays a reference role.Terminology Management Software in the CAT operating system can regulate all kinds of medical terminology，and add multiple industry terminology databases.It will automatically recognize the existing terms and the corresponding translation，and then offer references to ensure the consistency of translations.Translators can also use corpus classification storage to meet the needs.Thus the current CAT system is functional in application in corpus，and data resources and accumulation definitely play a major premise.〔6〕

2.Efficient Review and Proofreading System

Many paper works are needed before and after translation，both in English and Chinese，and the traditional proofreading methods are complicated，timeconsuming and it’s hard to avoid mistakes.Now，with proofreading function，CAT software can help reviewers detect the basic errors，such as omission，wrong format，terminology and the original error，and lack of alignment.This revision is more convenient and more efficient.In addition，through the network，the translators and the reviewers can do their work simultaneously via CAT software，which changed the pipelined translation－proofreading mode to a simultaneous mode，thus the speed and accuracy is raised greatly.

3.Open Sharing System

CAT software can be achieved between machine and machine，sharing between software and software，so many of the internal or external resources through the Internet with single or multiple translation memory，corpus and the terminology database can be connected at the same time，so the local corpus can be enriched.In addition，through the Internet，the translators and reviewers can share and review new terminology and language resources，thus repetitive translation and other repetitive work can be avoided to improve efficacy.

Ⅴ.Conclusions

MT and CAT are quite different with tight connection.In conclusion，there are 2 aspects：

1.Different Design Concepts

Machine Translation software is designed to make machines to translate，mainly for users whose foreign language is relatively poor；the purpose is to help them overcome basic language barrier.

Computer－aided Translation software is aiming at users whose foreign language level is relatively high；the function is aiding translation，not replace man’s work.The translator plays the key role in the process of translation and determines the quality of translation.

The concept of CAT is human－oriented，which pays more attention to improve the translator’s efficiency and reduce duplication of work，so terminology translation memory and man－machine interaction are designed.

2.Different Translation Engines

Based on grammar analysis and professional corpus，MT software focuses on the comprehensive function to ensure the effect of translation.While CAT software tends to rely on episodically automatic matching and professional translation staff is added in the process to meet their own needs.

In the process of translation，translation memory（TM）software automatically recalls results in TM.When the translator use it again，TM may search by comparing and matching translation units in the current sentences and libraries and pick them out in the system as the reference translation.

When translators do their work in the same project，they can share on line and create a local corpus to offer reference for others.

In addition，the management of numerous terms and multi－language translation highlight the features of CAT.

Compared with MT，CAT is more convenient and intelligent.The flexible translation memory technology，advanced and efficient proofreading system and open sharing system greatly emancipated productivity in saving time，maintain consistent terminology，ensure the quality and specify the layout.

With extensive use of CAT in the future，we are bound to usher in the era of computer translation in the global.

〔1〕Chen Yi，Fan Jiaolian，Computer－aided Translation Tendency of Translation of a New Century，Chinese Modern Education Equipment，vol.12，Dec.2008，pp.30－32.

〔2〕Bowker Lynne，Computer－aided Translation Technology：A Practical Introduction Ottwa，University of Ottawa Press，2002.

〔3〕Li Lu.Machine Translation and Computer Research and Exploration of Computer－aided Translation，Journal of Southeast University （Philosophy and Social Sciences Edition），vol.3，Jun.2002，pp.175－179.

〔4〕Xue Wenfeng.The Development and Present Situation of Chinese Machine Translation Software and Computer－aided Translation Software，Journal of Southwest University for Nationalities（Humanities Social Sciences Edition），vol.1，Jan.2008，pp.56－59.

〔5〕Shuttleworth，Mark and Cowie，Moria，Dictionary of Translation Studies，St.Jerome Publishing，1997.

〔6〕Ma Yaojuan，Wang Fangfang.Calculation Skills Necessary－aided Translation Technology，The Theory of Literature and Art，vol.1，Jan，2010，pp.95－97.