Contrastive analysis uses the differences between the learner's native language and the target language to examine errors in usage. Educators who use contrastive analysis would consider what the learner's native language is when looking for answers as to why certain mistakes are being made when speaking in the target language. For example, if the learner's native language places a direct object after the verb, it would stand to reason that, when speaking a new language, the learner would continue to place the direct object after the verb. Contrastive analysis searches for structural similarities and differences between the learner's native tongue and the language the student is learning (see Reference 1).
Error analysis is another way of analyzing a learner's language data. This approach looks at the errors made in speech and writing and analyzes them by the type of error being made. Different errors that can be made are sentence structure errors, verb tense errors, misplacement or misuse of words or mistakes in subject and verb agreement. Analyzing the type of error being made can help educators formulate appropriate lessons for improving learning. This type of analysis can give educators a better understanding of what the learner understands about the target language's rules and conventions (see Reference 2, page 3).
Educators that study developmental patterns of language acquisition can analyze data by examining the learner's progress with the developmental pattern. All language learners make the same mistakes at different stages of the learning process. Learners also acquire and display an understanding of grammatical rules in a certain sequence. Educators who analyze data through developmental patterns look at the errors learners make, such as errors of omission, transfer errors or over-generalization, and study the understanding of grammatical patterns in the learner. With this information, educators can provide learners with appropriate lessons for their skill levels (see Reference 3).
Learners of a target language may be consistent with their language use at each stage of development; however, there will always be some variability when errors occur. Educators who analyze data from the reference point of its variability recognize that, in one context, a learner may speak flawlessly, and in another a learner may make many errors. Linguistic context is often one reason as to why a learner may make an error. For example, a learner may be able to use the proper verb tense when talking about an activity, yet not when referring to a state of being. Situational context can also lead to errors. When speakers are in formal settings they are less likely to make errors than when in an informal setting. Educators who analyze the variability of errors in data will find interesting information about people's learning styles and skill levels (see Reference 4, page 6).