natural order hypothesis

In his article Krashen’s Monitor and Occam’s Razor Gregg points out some of the problems associated with his natural order hypothesis, as well as his lack of discussion as to why such an order exists. Most of the research this hypothesis is based on are studies of the acquisition of certain morphemes such as the third person, plural, and possessive –s, or the past tense –ed. One problem with these studies which Gregg points out is that these studies are examining formally dissimilar items which may not be comparable. In addition to this criticism the methods used to elicit samples from learners have also been criticized. The method used in most of these studies if I remember correctly is what is called “obligatory occasional analysis”. It is a method of elicitation which requires learners to supply the correct forms in obligatory occasions. One of the problems of this method is that it cannot account for overuse of these morphemes. For example, a learner may produce the correct form on an obligatory occasion but also produce it incorrectly in other occasions. Therefore it is difficult to tell to what degree the learner has actually acquired the morpheme. In addition to this problem these studies have also been criticized on the basis of what has been referred to as the “comparative fallacy”. This is based on the idea that a student’s interlanguage is a distinct from the target language with its own rules and forms. Interpreting the learner’s language in terms of the target norm may actually obscure our understanding of the interlanguage as a distinct system.

Despite these problems with the morpheme studies I became a little interested in the fact that certain morphemes such as the third person –s seem to be acquired rather late despite their frequency in the input. I became more interested in this subject after I read an article last week by Helen Bird et al. (Helen Bird, Mathew A. Lambon Ralph, Mark S Seidenberg, James L McClelland, and Karalyn Patterson, Deficits in Phonology and past-tense morphology: What’s the connection, Jouranal of Memory and Language 48 (2003) 502-56)

This was a study which examined the evidence for what is called a double disassociation between Wernicke’s and Broca’s aphasics in the formation of irregular and irregular past tense verbs. Previous studies had found that Broca’s aphasics are poor at producing regular past tense verbs as in walked and better at producing regular past tense verbs such as bought. Wernicke’s aphasics on the other hand have more difficulty producing past tense irregulars and little difficulty in producing regular forms. This has led some to posit two separate mechanisms for the formation of the past tense, one for regular forms and another for irregular forms. What this study looked at was whether phonological complexity could account for the problems in Broca’s aphasics ability to produce regular forms. By phonological complexity the authors looked at the consonant and vowel structure of the words as well as the consistency of voicing. For example the past tense irregular bought has a CVC structure while moved has a CVCC structure as well as a consistency of voicing on the last two consonants. The authors controlled for these features, phonological complexity and consistency of voicing, and found that the apparent advantage in the production of the irregular past in Brocas aphasics disappeared when these factors were controlled. This lead the authors to argue that there are not two separate systems responsible for forming regular and irregular past tense forms, but one system which draws on phonological and semantic knowledge.

After I read this study I became curious if there was similar work done on the morpheme acquisition in ESL. It would seem reasonable that certain morphemes are more difficult to acquire because of their phonological complexity, such as the –ed forms, or because of the consistency of voicing which make them less salient. For example, when we form a past tense if the final consonant is not voiced the –ed is also not voiced producing two sequential unvoiced consonants as in Walked /walkt/. According to the authors of this study this would make the –ed morpheme less salient phonologically.

I have not had time to do a thorough search of the literature, but I did find one study which examined this question among others. It was a study done by Goldschneider and Dekeyser: (Jennifer M. Goldschneider, Robert M. DeKeyser (2005) Explaining the “Natural Order of L2 Morpheme Acquisition” in English: A Meta-analysis of Multiple Determinants, Language Learning 55, 27-77)

This study examined whether five factors, perceptual saliency, semantic complexity, morphophonemic regularity, syntactic category, and frequency, could account for the order of acquisition of several morphemes. Their results indicated that the combination of these properties could explain to a large extent the acquisition order of the morphemes they included in their study. They suggest that these factors be grouped into a broader conceptualization of “salience” along with L1 transfer (which they did not include in their study) may account for most of the varience in the order of acquisition of the morphemes.

I don’t have a lot of time to go into detail of how they define each of the five factors which make up “salience”, and there may be some limitations with this type of study. They use what they call a meta-analysis which pools data from several other studies. I have a limited knowledge of research methods, so I don’t know how valid this type of research is. I did think it was an interesting study and wanted to share it with anyone who might be interested.

Krashen

The other authors in our readings did a pretty good job of pointing out many of the problems with Krashen’s theory of SLA. What concerns me the most with his ideas is how much he downplays the roles of production and practice. If his hypotheses are correct there is little need for students to ever speak. Students only need to have ‘low affective filters” and receive interesting and meaningful comprehensible input which is just a little above their current level, and perhaps after a “silent period” of a month to several years the student will decide to produce what he has acquired.

This view doesn’t really account for my experience in acquiring second languages, or the experiences of anyone else I know. Comprehension and production seem to me to be somewhat different processes. Most people are able to comprehend much more than they can actually produce. There is also the case of Broca’s aphasics whose comprehension is largely intact, but who have enormous difficulties in production. Of course comprehension most likely helps acquisition, but I think it more likely contributes not by focusing solely on meaning, but by paying attention to both meaning and form and in some way rehearsing constructions in our memory. For example, I don’t really have very much difficulty focusing on the meaning of what is being said as well as its form while I listen to lectures in French. When I hear a construction which is somewhat familiar to me It gets reinforced, and when I understand something produced in a new form (with the aid of extra-linguistic knowledge) I sometimes explicitly focus on the new form and attempt to store it in my memory.

It doesn’t seem reasonable that comprehensible input is “the true and only causative variable in second language acquisition”(Krashen 1983). I have always felt that producing and practicing the target language has allowed me to both practice learned forms and make them more automatic. Speaking also allows me to identify areas in my language proficiency which need more attention and those which I have little difficulty. For example, I may explicitly know how to form a passive sentence in Arabic, and I may also be able to automatically recognize when a passive is not formed correctly. When I speak, however, I may not form the passive correctly. I can immediately identify my own mistake, and realize that I have not completely mastered this construction, and through further practice make its production more automatic. If I never attempted to produce the passive I would not really know the degree to which I had acquired it.

In foreign language contexts students have very little opportunity to practice and test their linguistic skills outside of class. I am not necessarily opposed to allowing a short “silent period” while the students get more comfortable with the classroom routine, but I think production, making mistakes, and learning from them are essential to learning.

Wolf Children

As I was driving home from class I thought more about the significance of feral children to the Critical Period Hypothesis in first language acquisition. I was thinking about the problem backwards. Scientists who develop a hypothesis such as the CPH should not be interested in finding evidence which confirms the hypothesis, but evidence which could possibility falsify it. Because the discovery of feral children is rare, each new case provides an opportunity to test the CPH. It is because of the possibility of falsifying the CPH that every discovery of a feral child should concern anyone one who studies language acquisition, not because they will lead to confirmation of the CPH (confirmation is not the business of science) but because it is a new opportunity to test a hypothesis

Critical Period Hypothesis

I was a little surprised to discover at first just how controversial the idea of a CPH or “sensitive period” is in second language acquisition. After reading the articles, however, there appears to be little disagreement that younger language learners generally outperform adult beginners in the long run, and that it is common for child beginners to acquire native or near native proficiency in an L2 while it is rare or unattested for adult beginners (Marinova-Todd et al. 2000 p11). Most of the disagreement seems to be on what factors explain the general success of child learners and general failure of adult learners to acquire near native levels of proficiency and competence. The CPH and SPH are biological explanations while others such as Flege (1987) point to differences in affective and situational factors as an alternative explanation.

I am a little skeptical that affective and situational factors alone could account for the linear correlation between age of arrival and proficiency of children and the variability and lack of correlation for age of arrival and proficiency shown in studies such as Johnson and Newport study (Brown and Gonzo 75-112). It seems unlikely that children uniformly experience similar affective and motivational characteristics which lead to their success while different affective factors lead to general failure and invariability in adult populations. It would seem likely that there are many adult second language learners with high motivation who are less fearful of taking risks while there are many children who may have low motivation and are more fearful of making errors in production.

Anecdotally I have several friends, mostly Arabic speakers, who began learning English as adults, and who are married to non-Arabic speaking Americans, speak only English at home and work, and who appear to be highly motivated language learners. Despite the fact that they have lived here for a decade or more and are very proficient English speakers, they cannot pass for native speakers.

Whether or not there are biological maturational constraints on second language learning I found that it was difficult to make comparisons between the different articles assigned for class. For example the Flege article examined phonological aspects of L2 learning in both perception and production, the Johnson and Newport study looked at the ultimate attainment of grammatical competence (not performance), and the Wang and Kuhl article looked at the rate of attainment between children of different ages and adults in the perception of Mandan tones after a period of instructed learning. The problem with comparing these different approaches is that they are looking at different aspects of language and language acquisition. It is possible that there is a difference between instructed and naturalistic learning, so that the results of a study such as Wang and Kuhl may not be generalizable to a population which has learned in a more unstructured environment. That there is no difference or a difference which favors adults in more structured environments is not necessarily evidence against the Critical Period Hypothesis. It would just show that adults are more adept in more structured settings. Another problem with the Wang ad Kuhl study is that they are looking at the initial rate of learning and not the ultimate attainment of the learners. According to the Marinova-Todd et Al. article this distinction has been recognized with regard to the acquisition of morphosyntax for some time, citing the Krashen et Al. review (1979) which showed that older learners initially acquire a language faster than child learners, but that the younger learners will eventually attain greater proficiency levels. (Marivona-Todd et Al. P 12) In addition to this study the Flege article cites a study by Snow and Hoefnagel-Hohle which showed that adult accents may be judged more accurate than a childs after a short period of learning, but that the reverse is true after a longer period.