CALL Background
Before we start...
Happy Chinese New Year!!!Krashen’s Input Hypothesis and Its Influence on Duolingo’s Language Learning Approach
Second Language Acquisition (SLA) has seen significant developments over the past few decades, with various theories and hypotheses offering insights into how learners acquire a second language. One influential theory that aligns well with technology-enhanced language learning is the Input Hypothesis, proposed by Krashen (1982). It posits that learners acquire language when they are exposed to input that is slightly above their current level of competence, often referred to as “i+1”. This theory emphasizes the importance of comprehensible input in the language learning process. When learners receive input that they can mostly understand but which also contains new elements, they are more likely to internalize the new language structures.
Duolingo is one of the most popular language learning apps and one of the most downloaded education apps in the world. It offers diverse way to learn a language for beginners. Through the design of application, we can see the inspiration that Krashen's theory brought to them. The Duolingo team provides multimodal learning content, including audio, text, and interactive exercises. This content is easy to understand and gradually increase in difficulty to make sure that learners can comprehend and absorb new knowledge. The personalization of the learning material refers to a spotlight of Duolingo. It developed its in-house machine learning model Birdbrain, to predict the right difficulty level for each learner. Combined the result of the big data and user’s individual information, model would deliver the tailored content for users. The selection of the content responds to the “i+1” theory to improve language learning.
The appropriate content also contributes to learner’s engagement. Krashen's Affective Filter Hypothesis suggests that negative emotions such as anxiety can hinder the absorption of linguistic input. When students are given material that's too difficult, they often get frustrated and quit. Duolingo uses AI to keep its learners squarely in the zone where they remain engaged but are still learning at the edge of their abilities.
Krashen also differentiates between language acquisition and language learning. While language acquisition occurs naturally, language learning involves a conscious effort to study grammatical rules. Duolingo’s gamified approach fosters implicit learning, encouraging users to recognize and internalize grammatical patterns rather than explicitly memorizing rules. The app aims to replicate the natural language acquisition process, much like how children learn languages. However, due to the lack of explicit grammar instruction, some learners may feel that their grammatical knowledge is not systematically developed, which could hinder their ability to advance to higher levels of language proficiency. This is why some linguists criticize Duolingo for being potentially inefficient, arguing that it is better suited as a supplementary tool for language learning rather than a primary learning method.