The Challenge of Non-Stationary Feedbacks in Modeling the Response of Debris-Covered Glaciers to Climate Forcing

Ongoing changes in mountain glaciers affect local water resources, hazard potential and global sea level. An increasing proportion of remaining mountain glaciers are affected by the presence of a surface cover of rock debris, and the response of these debris-covered glaciers to climate forcing is different to that of glaciers without a debris cover. Here we take a back-to-basics look at the fundamental terms that control the processes of debris evolution at the glacier surface, to illustrate how the trajectory of debris cover development is partially decoupled from prevailing climate conditions, and that the development of a debris cover over time should prevent the glacier from achieving steady state. We discuss the approaches and limitations of how this has been treated in existing modeling efforts and propose that “surrogate world” numerical representations of debris-covered glaciers would facilitate the development of well-validated parameterizations of surface debris cover that can be used in regional and global glacier models. Finally, we highlight some key research targets that would need to be addressed in order to enable a full representation of debris-covered glacier system response to climate forcing.

Extracting Creativity from Narratives using Distributional Semantic Modeling

Narrative text permeates our lives from job applications to journalistic stories to works of fiction. Developing automated metrics that capture creativity in narrative text has potentially far reaching implications. Human ratings of creativity in narrative text are labor-intensive, subjective, and difficult to replicate. Across 27 different story prompts and over 3,500 short stories, we used distributional semantic modeling to automate the assessment of creativity in narrative texts. We tested a new metric to capture one key component of creativity in writing – a writer’s ability to connect divergent ideas. We termed this metric, word-to-word semantic diversity (w2w SemDiv). We compared six models of w2w SemDiv that varied in their computational architecture. The best performing model employed Bidirectional Encoder Representations Transformer (BERT), which generates context-dependent numerical representations of words (i.e., embeddings). The BERT w2w SemDiv scores demonstrated impressive predictive power, explaining up to 72% of the variance in human creativity ratings, even exceeding human inter-rater reliability for some tasks. In addition, w2w SemDiv scores generalized across Ethnicity and English language proficiency, including individuals identifying as Hispanic and L2 English speakers. We provide a tutorial with R code (osf.io/ath2s) on how to compute w2w SemDiv. This code is incorporated into an online web app (semdis.wlu.psu.edu) where researchers and educators can upload a data file with stories and freely retrieve w2w SemDiv scores.

Making sense of the relation between number sense and math

While several studies have shown that the performance on numerosity comparison tasks is related to individual differences in math abilities, others have failed to find such a link. These inconsistencies could be due to variations in which math was assessed, different stimulus generation protocols for the numerosity comparison task, or differences in inhibitory control. This within-subject study is a conceptual replication tapping into the relation between numerosity comparison, math, and inhibition in adults (N = 122). Three aspects of math ability were measured using standardized assessments: Arithmetic fluency, calculation, and applied problem solving skills. Participants’ inhibitory skills were measured using Stroop and Go/No-Go tasks with numerical and non-numerical stimuli. Finally, non-symbolic number sense was measured using two different versions of a numerosity comparison task that differed in the stimulus generation protocols (Panamath; Halberda, Mazzocco & Feigenson, 2008, https://doi.org/10.1038/nature07246; G&R, Gebuis & Reynvoet, 2011, https://doi.org/10.3758/s13428-011-0097-5). We find that performance on the Panamath task, but not the G&R task, related to measures of calculation and applied problem solving but not arithmetic fluency, even when controlling for inhibitory control. One possible explanation is that depending on the characteristics of the stimuli in the numerosity comparison task, the reliance on numerical and non-numerical information may vary and only when performance relies more on numerical representations, a relation with math achievement is found. Our findings help to explain prior mixed findings regarding the link between non-symbolic number sense and math and highlight the need to carefully consider variations in numerosity comparison tasks and math measures.

Two myths of representational measurement

Axiomatic measurement theories are commonly interpreted as claiming that, in order to quantify an empirical domain, the qualitative structure of data about that domain must be mapped to a numerical structure. Such mapping is supposed to be established independently, i.e., without presupposing that the domain can be quantified. This interpretation is based on two myths: that it is possible to independently infer the qualitative structure of objects from empirical data, and that the adequacy of numerical representations can only be justified by mapping such qualitative structures to numerical ones. I dispel the myths, and show that axiomatic measurement theories provide an inadequate characterization of the kind of evidence required to detect quantities.

COMPUTATIONAL CLASSIFICATION OF TIMBRE FOR RANKING OF TONE COLOR

The article describes a new computational approach for timbre classification for ranking tone color based on weighted feature extraction enabling a meaningful quantitative granular timbral description. Using a quantitative approach for algorithm development paired with a normative survey and data-driven testing, the authors find the proposed method to be a highly viable approach for computational timbre classification. As an example, we illustrate the proposed method against results from a conducted perceptual experiment. Our approach allows for improved accuracy for timbral description using numerical representations. Our research results supplement and improve the existing practice of using semantic descriptors for timbral description and can be used as an assistive tool in digital music production practices. This study aims to introduce a computational approach for timbre classification, enabling granularity in the timbral description. Our study suggests the possibility of timbral classification by numerical representation as a novel method for a more accurate mode of description for timbre.

A Note on Numerical Representations of Nested System of Strict Partial Orders

This note provides two numerical representations of a nested system of strict partial orders. The first representation is based on utility and threshold functions. We generalize the threshold representation of menu-dependent preferences by allowing the threshold to depend not only on the menu but also on the pair of alternatives under comparison. The threshold function can be interpreted as the distance between alternatives. The second representation is based on the aggregation of multi-dimensional preference. This representation describes a decision-making procedure where multiple criteria are gradually aggregated into an overall assessment.

‘Difference Is the One Thing That We Have in Common’

Television production is championing diversity in representation with record numbers compared to previous years. Netflix’s Sense8 is definitely amongst the highest scoring shows as concerns intersectional representation. Such remarkable representation was worth the 2016 GLAAD Outstanding Drama Series award, a prize granted to the most diverse television shows. However, this applause is geared solely to numerical representations while current academic discussion focuses more on the concept of fair representations. Not only is being represented of importance, but how one is represented. The present paper employs photovoice and photo elicitation to investigate how Sense8 fans articulate what constitutes a fair representation of queer gender identities within the show. The present research addresses two gaps in the literature. First, a methodological one: the employment of creative visual methodologies to transcend the limitations of the most common methods used for audience research —interviews and focus groups. Secondly, this study follows the contemporary conversation around fair representation by addressing what is now a gap in the existing literature on queer television: what is fair representation from an audience perspective? The results of this study show how audiences’ perspectives on fair representation differ from those formulated in public and academic debates.