While language models benefit immensely from their capacity to model large context (i.e., sequence of preceding tokens), the role of context is unclear in text tokenization, which is, in many cases, language model-driven to begin with. In this paper, we attempt to explore the role in three different writing systems and using three different text tokenization strategies (word-based, Morfessor, and BPE). In the first experiment, we examined how the size of context used for predicting the next token affects the ranking of the segmentation strategies i.t.o. language model surprisal. This effect was very writing system specific: minimal in case of English, and rank-reversing due to increased context size and token granularity in case of Turkish and Chinese. In the second experiment, we examined how context alters segmentation hypotheses when using language models to identify word boundaries. In this case, the effect was subtle: using context-aware, rather than context-free segment scores improved boundary recognition accuracy by up to 0.5%, once baseline effects were exploited.

Unsupervised learning of word representations involves capturing the contextual information surrounding word occurrences, which can be grounded in the observation that word form is largely disconnected from word meaning. While there are fewer reasons to believe that the same holds for sentences, learning through context has been carried over to learning representations of word sequences. However, this work pays minimal to no attention to the role of context in inferring sentence representations. In this article, we present a dialog act tag probing task designed to explicitly compare content-, and context-oriented sentence representations inferred on utterances of telephone conversations (SwDA). Our results suggest that there is no clear benefit of context-based sentence representations over content-based sentence representations. However, there is a very clear benefit of increasing the dimensionality of the sentence vectors in nearly all approaches.