Chart-to-Text: A Large-Scale Benchmark for Chart Summarization

TL;DR

Chart-to-Text provides a large-scale benchmark for chart summarization with 44,096 charts.

cs.CL 🔴 Advanced 2022-03-13 2 views
Shankar Kantharaj Rixie Tiffany Ko Leong Xiang Lin Ahmed Masry Megh Thakkar Enamul Hoque Shafiq Joty
chart summarization natural language generation data-to-text neural networks benchmarking

Key Findings

Methodology

The study employs two problem variations: one assumes the availability of the chart's underlying data table, while the other requires data extraction from chart images. State-of-the-art neural models, including image captioning and data-to-text generation techniques, are utilized. Models like TAB-T5 combine computer vision and natural language generation.

Key Results

  • TAB-T5 model achieved a BLEU score of 37.01 on the Statista dataset, outperforming other models.
  • OCR-T5 model scored 10.49 BLEU on the Pew dataset, highlighting challenges without data tables.
  • TAB-BART model achieved 77.14% in content selection accuracy, showing strong content generation capability.

Significance

This research provides a large-scale benchmark for chart summarization, addressing the gap of lacking large datasets and strong baseline models. It offers new perspectives on combining vision and language tasks, especially in scenarios without data tables.

Technical Contribution

The study introduces models combining computer vision and natural language generation, particularly TAB-T5 and OCR-T5, demonstrating effectiveness in chart summarization. It also provides a large-scale dataset covering various chart types and topics.

Novelty

This is the first large-scale benchmark for chart summarization, covering various chart types and topics. Compared to previous work, it not only offers a broader dataset but also introduces models combining vision and text.

Limitations

  • Models suffer from hallucinations and factual errors when generating summaries, especially in explaining complex patterns and trends.
  • Performance significantly drops without data tables.
  • Performance on multilingual data has not been verified.

Future Work

Future work can explore multilingual chart summarization, improve model performance without data tables, and develop better evaluation metrics to capture the quality of generated text.

AI Executive Summary

Charts are vital tools for data visualization but extracting key insights from them requires significant cognitive effort. The Chart-to-Text project provides a large-scale benchmark for chart summarization, including 44,096 charts covering a wide range of topics and types. The study employs two problem variations: one assumes the availability of the chart's underlying data table, while the other requires data extraction from chart images. State-of-the-art neural models, such as TAB-T5 and OCR-T5, are used, combining computer vision and natural language generation techniques.

Experimental results show that TAB-T5 performs best on the Statista dataset with a BLEU score of 37.01. However, models suffer from hallucinations and factual errors when generating summaries, especially in explaining complex patterns and trends. The study also finds that performance significantly drops without data tables.

This research provides a large-scale benchmark for chart summarization, addressing the gap of lacking large datasets and strong baseline models. Future work can explore multilingual chart summarization, improve model performance without data tables, and develop better evaluation metrics to capture the quality of generated text.

Deep Analysis

Background

Charts are vital tools for data visualization, widely used to present quantitative data. However, extracting key insights from charts can be challenging, especially when the information is complex. Early methods relied on template-based generation techniques, and recently, data-driven neural models have been used for describing tabular data, but these methods are not suitable for the visual features in charts.

Core Problem

The core problem of chart summarization is how to automatically generate natural language text to summarize key insights from charts. Existing methods lack large-scale datasets and strong baseline models, making it difficult to capture complex patterns and trends in charts.

Innovation

The core innovations of this study include: 1) providing a large-scale benchmark for chart summarization, covering various chart types and topics; 2) introducing models that combine computer vision and natural language generation, such as TAB-T5 and OCR-T5; 3) proposing two problem variations to handle scenarios with and without data tables.

Methodology

  • �� Dataset construction: Collected charts from Statista and Pew websites, annotated and classified data.
  • �� Model development: Used TAB-T5 and OCR-T5 models, combining computer vision and natural language generation.
  • �� Experimental design: Evaluated model performance using BLEU, CIDEr, and content selection accuracy.

Experiments

Experiments used the Statista and Pew datasets, containing 34,811 and 9,285 charts, respectively. Baseline models included TAB-Chart2text, TAB-BART, etc. Evaluation metrics included BLEU, CIDEr, and content selection accuracy.

Results

TAB-T5 achieved the highest BLEU score of 37.01 on the Statista dataset, outperforming other models. OCR-T5 performed poorly without data tables, highlighting the challenges in this scenario.

Applications

Chart summarization technology can be used for automatic report and article generation, improving the efficiency of information retrieval algorithms, and providing assistive tools for visually impaired individuals.

Limitations & Outlook

Models suffer from hallucinations and factual errors when generating summaries, especially in explaining complex patterns and trends. Performance significantly drops without data tables, requiring improvements in model robustness and accuracy.

Plain Language Accessible to non-experts

Imagine you're in a library with many books, each with a label. Charts are like these books, and chart summaries are like the labels. Our task is to generate a short label for each chart to help people quickly understand its content. To do this, we use a tool called TAB-T5, like a smart librarian who can quickly read the book's content and generate a concise label.

ELI14 Explained like you're 14

Hey there! You know those bar and pie charts you see at school? Imagine if they could talk and tell you their story. That's what we're doing here! We're using a super tool called TAB-T5 to let charts tell their own little stories. Sometimes they mess up, but we're working hard to make them smarter!

Glossary

BLEU (Bilingual Evaluation Understudy)

A metric for evaluating the similarity between machine-generated text and reference text, with higher scores indicating better quality.

Used to evaluate the quality of generated chart summaries.

CIDEr (Consensus-based Image Description Evaluation)

A metric that measures the similarity between generated text and reference text by computing TF-IDF weighted n-gram overlaps.

Used to assess the accuracy of model-generated text.

OCR (Optical Character Recognition)

A technology for extracting text from images, used to convert text in charts into processable data.

Used to extract text from chart images without data tables.

TAB-T5

A model combining computer vision and natural language generation to generate chart summaries.

Used as one of the baseline models for generating natural language descriptions of charts.

ResNet (Residual Network)

A deep neural network for image recognition, capable of effectively handling complex features in images.

Used as an image encoder to extract features from chart images.

Open Questions Unanswered questions from this research

  • 1 How to improve model performance without data tables? Current methods perform poorly on complex charts, requiring better visual feature extraction techniques.
  • 2 How to reduce hallucinations and factual errors in generated summaries? Better model training methods and datasets are needed.

Applications

Immediate Applications

Automatic Report Generation

By generating chart summaries, it helps businesses and researchers quickly write reports, improving work efficiency.

Long-term Vision

Intelligent Data Visualization

By improving chart summarization technology, achieve more intelligent data visualization tools to help users better understand complex data.

Abstract

Charts are commonly used for exploring data and communicating insights. Generating natural language summaries from charts can be very helpful for people in inferring key insights that would otherwise require a lot of cognitive and perceptual efforts. We present Chart-to-text, a large-scale benchmark with two datasets and a total of 44,096 charts covering a wide range of topics and chart types. We explain the dataset construction process and analyze the datasets. We also introduce a number of state-of-the-art neural models as baselines that utilize image captioning and data-to-text generation techniques to tackle two problem variations: one assumes the underlying data table of the chart is available while the other needs to extract data from chart images. Our analysis with automatic and human evaluation shows that while our best models usually generate fluent summaries and yield reasonable BLEU scores, they also suffer from hallucinations and factual errors as well as difficulties in correctly explaining complex patterns and trends in charts.

cs.CL