1.2 Objectives of SLA research

SLA research covers not only the study of those people who are learning an L2,but also the process of learning that language.In trying to probe into the process of learning an L2,researchers are seeking to answer the following three fundamental questions:

(1)What does the L2 learner come to know?

(2)How does the learner acquire the knowledge?

(3)Why are some learners more successful than other learners?

(Saville-Troike,2008:2)

SLA research aims to seek answers to the above questions.In order to answer the first question,researchers collect samples of learner language and try to describe their features.Generally speaking,the learner language is full of errors,and researchers usually start their study by classifying these errors.Also,researchers may record learners'speeches while they are communicating with native speakers or other learners,and then produce transcriptions of the recordings.By studying the transcriptions,researchers identify specific grammatical features such as negatives or interrogatives in the data,and describe the "rules" which could account for the learner's productions.The goal of research is essentially descriptive,that is,to record the learner language,to try to establish whether it manifests regularities of some kind,and to find out how it changes over time.

The second objective of SLA is to explain how the learner acquires the L2 knowledge.For example,does the learner depend on his innate ability to acquire L2 rules?How does he process language input?How does restructuring of L2 system take place?Does the learner acquire L2 knowledge by explicit or implicit means?How does he learn from interacting with others?Why do learner produce the L2 in the way they do?Why does learners'language exhibit marked "rules"?Why does the learner language change systematically over time?In order to answer these questions,researchers may consider both external and internal factors which affect SLA.The external factors are concerned with the social situation in which learning takes place.Researchers who are searching for external explanations of learner language make comprehensive use of ideas and methods from the sociolinguistic study of language.The internal factors which also make contributions to SLA are rooted in the mind of the learner,who employs mental processes to convert input into knowledge.The mental processes can be regarded as learning processes.By means of the learning processes,the learner constructs his L2 knowledge.

Another objective of SLA is connected with the third question,which focuses on individual language learners.Although the basic assumption in SLA research is that learner language offers evidence of universal learning processes,learners do vary significantly in their rate of learning,their approach to learning,and especially in their final achievements.The study of individual learner differences seeks to document the factors which contribute to different kinds of variation.