Structural Features of Undergraduate Writing: A Computational Approach

Abstract

Background: Over a decade ago, the Stanford Study of Writing (SSW) collected more than 15,000 writing samples from undergraduate students, but to this point the corpus has not been analyzed using computational methods. Through the use of natural language processing (NLP) techniques, this study attempts to reveal underlying structures in the SSW, while at the same time developing a set of interpretable features for computationally understanding student writing. These features fall into three categories: topic-based features that reveal what students are writing about; stance-based features that reveal how students are framing their arguments; and structure-based features that reveal sentence complexity. Using these features, we are able to characterize the development of the SSW participants across four years of undergraduate study, specifically gaining insight into the different trajectories of humanities, social science, and STEM students. While the results are specific to Stanford University’s undergraduate program, they demonstrate that these three categories of features can give insight into how groups of students develop as writers.Literature Review: The Stanford Study of Writing (Lunsford et al., 2008; SSW, 2018) involved the collection of more than 15,000 writing samples from 189 students in the Stanford class of 2005. The literature surrounding the original study is largely qualitative (Fishman, Lunsford, McGregor, & Otuteye, 2005; Lunsford, 2013; Lunsford, Fishman, & Liew, 2013), so this study makes a first attempt at a quantitative analysis of the SSW. When considering the ethics of a computational approach, we find it important not to stray into the territory of writing evaluation, as purely evaluative systems have been shown to have limited instructional use in the classroom (Chen & Cheng, 2008; Weaver, 2006). Therefore, we find it important to take a descriptive, rather than evaluative approach. All of the features that we extract are both interpretable and grounded in prior research. Topic modeling has been used on undergraduate writing to improve the prediction of neuroticism and depression in college students (Resnik, Garron, & Resnik, 2013), stance markers have been used to show the development of undergraduate writers (Aull & Lancaster, 2014), and parse trees have been used to measure the syntactic complexity of student writing (Lu, 2010).Research Questions: What computational features are useful for analyzing the development of student writers? Based on these features, what insights can we gain into undergraduate writing at Stanford and similar institutions?Methodology: To extract topic features, we use LDA topic modeling (Blei, Ng, & Jordan, 2003) with Gibbs Sampling (Griffiths, 2002). To extract stance features, we replicate the stance markers approach from a past study (Aull & Lancaster, 2014). To describe sentence structure, we use parse trees generated using  Shift-Reduce dependency parsing (Sagae & Tsujii, 2008). For each parse tree, we use the tree depth and the average dependency length as heuristics for the syntactic complexity of the sentence.Results: Topic modeling was useful for sorting papers into academic disciplines, as well as for distinguishing between argumentative and personal writing. Stance markers helped us characterize the intersection between the majors that students hold and the topics that they are writing about at a given time. Parse tree complexity demonstrated differences between writing in different disciplines. In addition, we found that students of different disciplines have different syntactic features even during their first year at Stanford.Discussion: Topic modeling has given us a picture of interdisciplinary study at Stanford by showing how often students in the SSW wrote about topics outside their majors. Furthermore, studying interdisciplinary Stanford students allowed us to examine the intersection of a student’s major and current topic of writing when analyzing the other two sets of features. Stance markers in the SSW show that both field of study and topic of writing influence the ways in which students employ metadiscourse. In addition, when looking at stance across years, we see that Seniors regress towards their First-Year habits. The complexity results raise the question of whether different disciplines have different “ideal” levels of writing complexity.Conclusions: The present study yields insight into undergraduate writing at Stanford in particular. Notably, we find that students develop most as writers during their first two years and that students of different majors develop as writers in different ways. We consider our three categories of features to be useful because they were able to give us these insights into the dataset. We hope that, moving forward, educators will be able to use this kind of analysis to understand how their students are developing as writers.