This document discusses several models of second language acquisition and individual difference factors that influence language learning. It summarizes several key models including Krashen's Monitor Model, Brown and Fraser's framework, Gardner's educational model, Skehan's model of influences, and Spolsky's model. It also discusses individual difference variables like age, attitudes, motivation, intelligence, language aptitude, previous knowledge, familiarity with computers, interaction with native speakers, and language used in the community. The summary concludes that while study findings vary, most research shows these individual factors significantly impact language learning outcomes and interact with each other in complex ways.