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James Wexler

James Wexler

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Google Publications
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    Automatic Histograms: Leveraging Language Models for Text Dataset Exploration
    Extended Abstracts of the CHI Conference on Human Factors in Computing Systems (CHI EA '24), ACM, Honolulu, HI, USA (2024), pp. 9
    Preview abstract Making sense of unstructured text datasets is perennially difficult, yet increasingly relevant with Large Language Models. Data practitioners often rely on dataset summaries, especially distributions of various derived features. Some features, like toxicity or topics, are relevant to many datasets, but many interesting features are domain specific, e.g., instruments and genres for a music dataset, or diseases and symptoms for a medical dataset. Accordingly, data practitioners often run custom analyses for each dataset, which is cumbersome and difficult, or use unsupervised methods. We present AutoHistograms, a visualization tool leveraging LLMs. AutoHistograms automatically identifies relevant entity-based features, visualizes their distributions, and allows the user to interactively query the dataset for new categories of entities. In a user study with (n=10) data practitioners, we observe that participants were able to quickly onboard to AutoHistograms, use the tool to identify actionable insights, and conceptualize a broad range of applicable use cases. We also describe a variety of usage scenarios from different types of users to highlight how this app can provide value in many different contexts. Finally, we present a quantitative evaluation of the tool. Together, this tool and user study contribute to the growing field of LLM-assisted sensemaking tools. View details
    LLM Comparator: Visual Analytics for Side-by-Side Evaluation of Large Language Models
    Michael Xieyang Liu
    Krystal Kallarackal
    Extended Abstracts of the CHI Conference on Human Factors in Computing Systems (CHI EA '24), ACM (2024)
    Preview abstract Automatic side-by-side evaluation has emerged as a promising approach to evaluating the quality of responses from large language models (LLMs). However, analyzing the results from this evaluation approach raises scalability and interpretability challenges. In this paper, we present LLM Comparator, a novel visual analytics tool for interactively analyzing results from automatic side-by-side evaluation. The tool supports interactive workflows for users to understand when and why a model performs better or worse than a baseline model, and how the responses from two models are qualitatively different. We iteratively designed and developed the tool by closely working with researchers and engineers at Google. This paper details the user challenges we identified, the design and development of the tool, and an observational study with participants who regularly evaluate their models. View details
    Take it, Leave it, or Fix it: Measuring Productivity and Trust in Human-AI Collaboration
    29th International Conference on Intelligent User Interfaces (IUI ’24), ACM, New York, NY, USA (2024)
    Preview abstract Although recent developments in generative AI have greatly enhanced the capabilities of conversational agents such as Google's Bard or OpenAI's ChatGPT, it's unclear whether the usage of these agents aids users across various contexts. To better understand how access to conversational AI affects productivity and trust, we conducted a mixed-methods, task-based user study, observing 76 software engineers (N=76) as they completed a programming exam with and without access to Bard. Effects on performance, efficiency, satisfaction, and trust vary depending on user expertise, question type (open-ended "solve" questions vs. definitive "search" questions), and measurement type (demonstrated vs. self-reported). Our findings include evidence of automation complacency, increased reliance on the AI over the course of the task, and increased performance for novices on “solve”-type questions when using the AI. We discuss common behaviors, design recommendations, and impact considerations to improve collaborations with conversational AI. View details
    Preview abstract Interpretability techniques aim to provide the rationale behind a model's decision, typically by explaining either an individual prediction (local explanation, e.g. `why is this patient diagnosed with this condition') or a class of predictions (global explanation, e.g. `why is this set of patients diagnosed with this condition in general'). While there are many methods focused on either one, few frameworks can provide both local and global explanations in a consistent manner. In this work, we combine two powerful existing techniques, one local (Integrated Gradients, IG) and one global (Testing with Concept Activation Vectors), to provide local and global concept-based explanations. We first sanity check our idea using two synthetic datasets with a known ground truth, and further demonstrate with a benchmark natural image dataset. We test our method with various concepts, target classes, model architectures and IG parameters (e.g. baselines). We show that our method improves global explanations over vanilla TCAV when compared to ground truth, and provides useful local insights. Finally, a user study demonstrates the usefulness of the method compared to no or global explanations only. We hope our work provides a step towards building bridges between many existing local and global methods to get the best of both worlds. View details
    The Language Interpretability Tool: Extensible, Interactive Visualizations and Analysis for NLP Models
    Ann Yuan
    Andy Coenen
    Sebastian Gehrmann
    Ellen Jiang
    Carey Radebaugh
    Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing: System Demonstrations, Association for Computational Linguistics (to appear)
    Preview abstract We present the Language Interpretability Tool (LIT), an open-source platform for visualization and understanding of NLP models. We focus on core questions about model behavior: Why did my model make this prediction? When does it perform poorly? What happens under a controlled change in the input? LIT integrates local explanations, aggregate analysis, and counterfactual generation into a streamlined, browser-based interface to enable rapid exploration and error analysis. We include case studies for a diverse set of workflows, including exploring counterfactuals for sentiment analysis, measuring gender bias in coreference systems, and exploring local behavior in text generation. LIT supports a wide range of models--including classification, seq2seq, and structured prediction--and is highly extensible through a declarative, framework-agnostic API. LIT is under active development, with code and full documentation available at https://github.com/pair-code/lit. View details
    Towards Automatic Concept-based Explanations
    Amirata Ghorbani
    James Zou
    Been Kim
    NeurIPS (2019)
    Preview abstract Interpretability has become an important topic of research as more machine learning (ML) models are deployed and widely used to make important decisions. Most of the current explanation methods provide explanations through feature importance scores, which identify features that are salient for each individual input. However, how to systematically summarize and interpret such per sample feature importance scores itself is challenging. In this work, we propose principles and desiderata for \emph{concept} based explanation, which goes beyond per-sample features to identify higher level human-understandable concepts that apply across the entire dataset. We develop a new algorithm, ACE, to automatically extract visual concepts. Our systematic experiments demonstrate that ACE discovers concepts that are human-meaningful, coherent and salient for the neural network's predictions. View details
    Bach Doodle: Approachable music composition with machine learning at scale
    Curtis Hawthorne
    Monica Dinculescu
    Leon Hong
    Jacob Howcroft
    Proceedings of the 20th International Society for Music Information Retrieval Conference (ISMIR) (2019)
    Preview abstract Many of us like music, but composing can feel intimidating, not knowing where to begin. Even when we have a melody, without sufficient skills in harmony we are deterred from developing it into a composition. Machine learning could potentially extend our creative abilities by offering generative models that can fill in the missing parts of our composition. To make music composition more approachable, we designed a composition web-app where users can create their own melody and have it harmonized by a machine learning model. For inputting melodies, we designed a simplified sheet music interface that facilitates easy trial and error, and found that users adapted to it quickly even when they were not familiar with western music notation. Users can rapidly explore different possibilities in harmonizations by tweaking their melody and requesting for new harmonizations. The harmonizations are provided by Coconet, a flexible generative model of counterpoint. Several technical challenges had to be overcome to support an interactive experience at scale. First, as most users do not have dedicated hardware to run machine learning models, we re-implemented Coconet in TensorFlow.js so that it could run in the browser. Second, our initial re-implementation took more than 40 seconds to generate two measures of music. By adopting dilated depth-wise separable convolutions and model quantization, we reduced it down to 2 seconds. Third, to prepare for large-scale deployment, we calibrated a speed test to determine if a user’s device is fast enough for running the model in the browser, if not the harmonization requests were sent to remote TPU servers. In three days, the web-app received more than 50 million queries for harmonization around the world. Users could choose to rate their compositions and contribute them to a public dataset, which we are releasing with this paper. We hope that the community might find this dataset useful for, ranging from ethnomusicological studies, to music education to improving machine learning models. We end with a quote from a user: “It's really fun to play with. This might be the first time in my life I feel competent at music.” View details
    Preview abstract A key challenge in developing and deploying Machine Learning (ML) systems is understanding their performance across a wide range of inputs. To address this challenge, we created the What-If Tool, an open-source application that allows practitioners to probe, visualize, and analyze ML systems, with minimal coding. The What-If Tool lets practitioners test performance in hypothetical situations, analyze the importance of different data features, and visualize model behavior across multiple models and subsets of input data. It also lets practitioners measure systems according to multiple ML fairness metrics. We describe the design of the tool, and report on real-life usage at different organizations. View details
    Scalable and accurate deep learning for electronic health records
    Alvin Rishi Rajkomar
    Eyal Oren
    Kai Chen
    Nissan Hajaj
    Mila Hardt
    Xiaobing Liu
    Jake Marcus
    Patrik Per Sundberg
    Kun Zhang
    Yi Zhang
    Gerardo Flores
    Gavin Duggan
    Jamie Irvine
    Kurt Litsch
    Alex Mossin
    Justin Jesada Tansuwan
    De Wang
    Dana Ludwig
    Samuel Volchenboum
    Kat Chou
    Michael Pearson
    Srinivasan Madabushi
    Nigam Shah
    Atul Butte
    npj Digital Medicine (2018)
    Preview abstract Predictive modeling with electronic health record (EHR) data is anticipated to drive personalized medicine and improve healthcare quality. Constructing predictive statistical models typically requires extraction of curated predictor variables from normalized EHR data, a labor-intensive process that discards the vast majority of information in each patient’s record. We propose a representation of patients’ entire raw EHR records based on the Fast Healthcare Interoperability Resources (FHIR) format. We demonstrate that deep learning methods using this representation are capable of accurately predicting multiple medical events from multiple centers without site-specific data harmonization. We validated our approach using de-identified EHR data from two U.S. academic medical centers with 216,221 adult patients hospitalized for at least 24 hours. In the sequential format we propose, this volume of EHR data unrolled into a total of 46,864,534,945 data points, including clinical notes. Deep learning models achieved high accuracy for tasks such as predicting: in-hospital mortality (AUROC across sites 0.93-0.94), 30-day unplanned readmission (AUROC 0.75-0.76), prolonged length of stay (AUROC 0.85-0.86), and all of a patient’s final discharge diagnoses (frequency-weighted AUROC 0.90). These models outperformed state-of-the-art traditional predictive models in all cases. We also present a case-study of a neural-network attribution system, which illustrates how clinicians can gain some transparency into the predictions. We believe that this approach can be used to create accurate and scalable predictions for a variety of clinical scenarios, complete with explanations that directly highlight evidence in the patient’s chart. View details
    Preview abstract The interpretation of deep learning models is a challenge due to their size, complexity, and often opaque internal state. In addition, many systems, such as image classifiers, operate on low-level features rather than high-level concepts. To address these challenges, we introduce Concept Activation Vectors (CAVs), which provide an interpretation of a neural net's internal state in terms of human-friendly concepts. The key idea is to view the high-dimensional internal state of a neural net as an aid, not an obstacle. We show how to use CAVs as part of a technique, Testing with CAVs (TCAV), that uses directional derivatives to quantify the degree to which a user-defined concept is important to a classification result--for example, how sensitive a prediction of “zebra” is to the presence of stripes. Using the domain of image classification as a testing ground, we describe how CAVs may be used to explore hypotheses and generate insights for a standard image classification network as well as a medical application. View details
    Visualizing Dataflow Graphs of Deep Learning Models in TensorFlow
    Kanit Wongsuphasawat
    Daniel Smilkov
    Dandelion Mane
    Doug Fritz
    Dilip Krishnan
    IEEE Transaction on Visualization and Computer Graphics (2017)
    Preview abstract We present a design study of the TensorFlow Graph Visualizer, part of the TensorFlow machine intelligence platform. This tool helps users understand complex machine learning architectures by visualizing their underlying dataflow graphs. The tool works by applying a series of graph transformations that enable standard layout techniques to produce a legible interactive diagram. To declutter the graph, we decouple non-critical nodes from the layout. To provide an overview, we build a clustered graph using the hierarchical structure annotated in the source code. To support exploration of nested structure on demand, we perform edge bundling to enable stable and responsive cluster expansion. Finally, we detect and highlight repeated structures to emphasize a model’s modular composition. To demonstrate the utility of the visualizer, we describe example usage scenarios and report user feedback. Overall, users find the visualizer useful for understanding, debugging, and sharing the structures of their models. View details
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