aspects of speech: complexity, accuracy, and fluency. Of these three, planning effects on fluency have had the most research attention. Communication strategies are conscious strategies that learners employ to get around any instances of communication breakdown they may experience. Their effect on second-language acquisition is unclear, with some researchers claiming they help it, and others claiming the opposite. An important idea in recent cognitive approaches is the way that learning itself changes over development. For example, connectionist models that explain L1 language phenomena in different languages (e.g., Japanese, English ) can also be used to develop L2 models by first training on the L1 (e.g., Korean) and then training on the L2 (e.g. English). By using different learning rates for syntax and lexical learning that change over development, the model can explain sensitive period effects and differences in the effect of language exposure on different types of learners. Sociocultural factors From the early days of the discipline, researchers have also acknowledged that social aspects play an important role. There have been many different approaches to the sociolinguistic study of second-language acquisition, and indeed, according to Rod Ellis, this plurality has meant that "sociolinguistic SLA is replete with a bewildering set of terms referring to the social aspects of L2 acquisition". Common to each of these approaches, however, is a rejection of language as a purely psychological phenomenon; instead, sociolinguistic research views the social context in which language is learned as essential for a proper understanding of the acquisition process. Ellis identifies three types of social structures that affect the acquisition of second languages: sociolinguistic setting, specific social factors, and situational factors. Sociolinguistic setting refers to the role of the second language in society, such as whether it is spoken by a majority or a minority of the population, whether its use is widespread or restricted to a few functional roles, or whether the society is predominantly bilingual or monolingual. Ellis also includes the distinction of whether the second language is learned in a natural or an educational setting. Specific social factors that can affect second-language acquisition include age, gender, social class, and ethnic identity, with ethnic identity being the one that has received most research attention. Situational factors are those that vary between each social interaction. For example, a learner may use more polite language when talking to someone of higher social status, but more informal language when talking with