Question: What can be predicted by the simple most-common value classifier they observe?
Evidence: Given the large collections of unstructured and semi-structured data available on the web, there is a crucial need to enable quick and efficient access to the knowledge content within them. Traditionally, the field of information extraction has focused on extracting such knowledge from unstructured text documents, such as job postings, scientific papers, news articles, and emails. However, the content on the web increasingly contains more varied types of data, including semi-structured web pages, tables that do not adhere to any schema, photographs, videos, and audio. Given a query by a user, the appropriate information may appear in any of these different modes, and thus there's a crucial need for methods to construct knowledge bases from different types of data, and more importantly, combine the evidence in order to extract the correct answer.
Motivated by this goal, we introduce the task of multimodal attribute extraction. Provided contextual information about an entity, in the form of any of the modes described above, along with an attribute query, the goal is to extract the corresponding value for that attribute. While attribute extraction on the domain of text has been well-studied BIBREF0 , BIBREF1 , BIBREF2 , BIBREF3 , BIBREF4 , to our knowledge this is the first time attribute extraction using a combination of multiple modes of data has been considered. This introduces additional challenges to the problem, since a multimodal attribute extractor needs to be able to return values provided any kind of evidence, whereas modern attribute extractors treat attribute extraction as a tagging problem and thus only work when attributes occur as a substring of text.
In order to support research on this task, we release the Multimodal Attribute Extraction (MAE) dataset, a large dataset containing mixed-media data for over 2.2 million commercial product items, collected from a large number of e-commerce sites using the Diffbot Product API. The collection of items is diverse and includes categories such as electronic products, jewelry, clothing, vehicles, and real estate. For each item, we provide a textual product description, collection of images, and open-schema table of attribute-value pairs (see Figure 1 for an example). The provided attribute-value pairs only provide a very weak source of supervision; where the value might appear in the context is not known, and further, it is not even guaranteed that the value can be extracted from the provided evidence. In all, there are over 4 million images and 7.6 million attribute-value pairs. By releasing such a large dataset, we hope to drive progress on this task similar to how the Penn Treebank BIBREF5 , SQuAD BIBREF6 , and Imagenet BIBREF7 have driven progress on syntactic parsing, question answering, and object recognition, respectively.
To asses the difficulty of the task and the dataset, we first conduct a human evaluation study using Mechanical Turk that demonstrates that all available modes of information are useful for detecting values. We also train and provide results for a variety of machine learning models on the dataset. We observe that a simple most-common value classifier, which always predicts the most-common value for a given attribute, provides a very difficult baseline for more complicated models to beat (33% accuracy). In our current experiments, we are unable to train an image-only classifier that can outperform this simple model, despite using modern neural architectures such as VGG-16 BIBREF8 and Google's Inception-v3 BIBREF9 . However, we are able to obtain significantly better performance using a text-only classifier (59% accuracy). We hope to improve and obtain more accurate models in further research.
We observe that a simple most-common value classifier, which always predicts the most-common value for a given attribute, provides a very difficult baseline for more complicated models to beat (33% accuracy).
Answer: The most-common value for a given attribute.