Time Series

Liu, Yufeng and Tay, Dennis and Mellow, Dean (2025) Time Series. In: The Encyclopedia of Applied Linguistics :. Wiley, pp. 1-7. ISBN 9781405194730

Abstract

In the broad field of applied linguistics, language data captured sequentially at regular time intervals has led to the emergence of various instances of time series data. Nonetheless, a noticeable gap remains in the explicit application of time series analysis (TSA) methods in existing research. This article posits that such application holds promise across the expansive scope of applied linguistics, including domains such as second language acquisition (SLA), critical discourse analysis (CDA), and translation studies (TS). Following a brief introduction to time series, the article outlines two distinct TSA designs, each underpinned by empirical case studies. First, TSA employing simple linear regression is exemplified through an SLA context, wherein the lexical transitions within 201-day narratives of a 12-year-old Spanish learner of English are examined. Second, TSA employing the Box–Jenkins method with Autoregressive Integrated Moving Average (ARIMA) models is introduced in a CDA context, wherein 109 makeup tutorial videos on a popular YouTube channel were collected and analyzed. Beyond these methodological exemplars, the article discusses supplementary design possibilities and analytical avenues that may prove valuable to scholars from diverse linguistic backgrounds.