Transfer, interference and overgeneralization

Human beings approach any new problem with an existing set of cognitive structures and, through insight, logical thinking, and various forms of hypothesis testing, call upon whatever prior experiences they have had and whatever cognitive structures they possess to attempt a solution. In the literature on language learning processes, three terms have commonly been singled out for explication: transfer, interference, and overgeneralization. The three terms are sometimes mistakenly considered to represent separate processes; they are more correctly understood as several manifes­tations of one principle of learning—the interaction of previously learned material with a present learning event. From the beginning of life the human organism, or any organism for that matter, builds a structure of knowledge by the accumulation of experiences and by the storage of aspects of those experiences in memory. Let us consider these common terms in two associated pairs.

Transfer is a general term describing the carryover of previous per­formance or knowledge to subsequent learning. Positive transfer occurs when the prior knowledge benefits the learning task—that is, when a pre­vious item is correctly applied to present subject matter. Negative transfer occurs when previous performance disrupts the performance of a second task. The latter can be referred to as interference,in that previously learned material interferes with subsequent material—a previous item is incorrectly transferred or incorrectly associated with an item to be learned.

It has been common in second language teaching to stress the role of interference—that is, the interfering effects of the native language on the target (the second) language. It is of course not surprising that this process has been so singled out, for native language interference is surely the most immediately noticeable source of error among second language learners. The saliency of interference has been so strong that some have viewed second language learning as exclusively involving the overcoming of the effects of the native language. It is clear from learning theory that a person will use whatever previous experience he or she has had with language to facilitate the second language learning process. The native language is an obvious set of prior experiences. Sometimes the native language is nega­tively transferred, and we say then that interference has occurred.

It is exceedingly important to remember, however, that the native lan­guage of a second language learner is often positively transferred, in which case the learner benefits from the facilitating effects of the first language. In the above sentence, for example, the correct one-to-one word order cor­respondence, the personal pronoun, and the preposition have been posi­tively transferred from French to English. We often mistakenly overlook the facilitating effects of the native language in our penchant for analyzing errors in the second language and for overstressing the interfering effects of the first language.

In the literature on second language acquisition, interference is almost as frequent a term as overgeneralization,which is, of course, a particular subset of generalization. Generalization is a crucially important and per­vading strategy in human learning. To generalize means to infer or derive a law, rule, or conclusion, usually from the observation of particular instances. The principle of generalization can be explained by Ausubel's concept of meaningful learning. Meaningful learning is, in fact, generaliza­tion: items are subsumed (generalized) under higher-order categories for meaningful retention. Much of human learning involves generalization. The learning of concepts in early childhood is a process of generalizing. A child who has been exposed to various kinds of animals gradually acquires a gen­eralized concept of "animal." That same child, however, at an early stage of generalization, might in his or her familiarity with dogs see a horse for the first time and overgeneralize the concept of "dog" and call the horse a dog. Similarly, a number of animals might be placed into a category of "dog" until the general attributes of a larger category, "animal," have been learned.

In second language acquisition it has been common to refer to over-generalization as a process that occurs as the second language learner acts within the target language, generalizing a particular rule or item in the second language—irrespective of the native language—beyond legitimate bounds. We have already observed that children, at a particular stage of learning English as a native language, overgeneralize regular past-tense end­ings (walked, opened) as applicable to all past-tense forms (goed, flied) until they recognize a subset of verbs that belong in an "irregular" category. After gaining some exposure and familiarity with the second language, second language learners similarly will overgeneralize within the target lan­guage. Typical examples in learning English as a second language are past-tense regularization and utterances like "John doesn't can study" (negativization requires insertion of the do auxiliary before verbs) or "He told me when should I get off the train" (indirect discourse requires normal word order, not question word order, after the wh- word). Unaware that these rules have special constraints, the learner overgeneralizes. Such over-generalization is committed by learners of English from almost any native language background.

Many have been lead to believe that there are only two processes of second language acquisition: interference and overgeneralization. This is obviously a misconception. First, interference and overgeneralization are negative counterparts of the facilitating processes of transfer and generalization. (Illustration - 2.1).

Illustration 2.1 - Transfer, overgeneralization and interference.

Second, while they are indeed aspects of somewhat different processes, they are represent fundamentals and interrelated components of all human learning, and when applied to SLA are simply extensions of general psychological principles. Interference of the first language is simply a form of generalizing that takes prior the first language experience and applies them incorrectly. Overgeneralization is an incorrect application – negative transfer of previously learned second language material to a present second language context. All generalizing involves transfer and all transfer involves generalizing.