Blog
The latest news from Google AI
Building Google Dataset Search and Fostering an Open Data Ecosystem
Wednesday, September 26, 2018
Posted by Matthew Burgess and Natasha Noy, Google AI
Earlier this month we launched
Google Dataset Search
, a tool designed to make it easier for researchers to discover datasets that can help with their work. What we colloquially call "Google Scholar for data,” Google Dataset Search is a search engine across metadata for millions of datasets in thousands of repositories across the Web. In this post, we go into some detail of how Dataset Search is built, outlining what we believe will help develop an open data ecosystem, and we also address the question that we received frequently since the Dataset Search
launch
, "
Why is my dataset not showing up in Google Dataset Search?
”
An Overview
At a very high level, Google Data Search relies on dataset providers, big and small,
adding structured metadata on their sites
using the open
schema.org/Dataset
standard. The metadata specifies the salient properties of each dataset: its name and description, spatial and temporal coverage, provenance information, and so on. Dataset Search uses this metadata, links it with other resources that are available at Google (more on this below!), and builds an index of this enriched corpus of metadata. Once we built the index, we can start answering user queries — and figuring out which results best correspond to the query.
An overview of the technology behind Google Dataset Search
Using Structured Metadata from Data Providers
When Google's search engine processes a Web page with schema.org/Dataset mark-up, it understands that there is dataset metadata there and processes that structured metadata to create "records" describing each annotated dataset on a page. The use of schema.org allows developers to embed this structured information into HTML, without affecting the appearance of the page while making the semantics of the information visible to all search engines.
However, no matter how precise schema.org definitions or
guidelines
are, some metadata will inevitably be incomplete, wrong, or entirely missing. Furthermore, distinctions between some fields can be vague: is the dataset repository a publisher or a provider of a dataset? How do we distinguish between citations to a scientific paper that describes the creation of the dataset vs. papers describing its use? Indeed, many of these questions often generate active
scholarly discussions
.
Despite these variations, Dataset Search must provide a uniform and predictable user experience on the front end. Therefore, in some cases we substitute a more general field name (e.g., “
provided by
”) to display the values coming from multiple other fields (e.g., “
publisher
”, “
creator
”, etc.). In other cases, we are not able to use some of the fields at all: if a specific field is being misinterpreted in many different ways by dataset providers, we bypass that field for now and work with the community to clarify the guidelines. In each decision, we had one specific question that helped us in difficult cases "What will help data discovery the most?" This focus on the task that we were addressing made some of the problems easier than they seemed at first.
Connecting Replicas of Datasets
It is very common for a dataset, in particular a popular one, to be present in more than one repository. We use a variety of signals to determine when two datasets are replicas of each other. For example, schema.org has a way to specify the connection explicitly, through
schema.org/sameAs
, which is the best way to link different replicas together and to point to the canonical source of a dataset. Other signals include two datasets descriptions pointing to the same canonical page, having the same
Digital Object Identifier
(DOI), sharing links for downloading the dataset, or having a large overlap in other metadata fields. None of these signals are perfect in isolation, therefore we combine them to get the strongest possible indication of when two datasets are the same.
Reconciling to the Google Knowledge Graph
Google's
Knowledge Graph
is a powerful platform that describes and links information about many entities, including the ones that appear in dataset metadata: organizations providing datasets, locations for spatial coverage of the data, funding agencies, and so on. Therefore, we try to reconcile information mentioned in the metadata fields with the items in the Knowledge Graph. We can do this reconciliation with good precision for two main reasons. First, we know the types of items in the Knowledge Graph and the types of entities that we expect in the metadata fields. Therefore, we can limit the types of entities from the Knowledge Graph that we match with values for a particular metadata field. For example, a provider of a dataset should match with an organization entity in the Knowledge Graph and not with, say, a location. Second, the context of the Web page itself helps reduce the number of choices, which is particularly useful for distinguishing between organizations that share the same acronym. For example, the acronym CAMRA can stand for “Chilbolton Advanced Meteorological Radar” or “Campaign for Real Ale”. If we use terms from the Web page, we can then more easily determine that CAMRA is in fact the Chilbolton Radar when we see terms such as “
clouds
”, “
vapor
”, and “
water
” on the page.
This type of reconciliation opens up lots of possibilities to improve the search experience for users. For instance, Dataset Search can localize results by showing reconciled values of metadata in the same language as the rest of the page. Additionally, it can rely on synonyms, correct misspellings, expand acronyms, or use other relations in the Knowledge Graph for query expansion.
Linking to other Google Resources
Google has many other data resources that are useful in augmenting the dataset metadata, such as
Google Scholar
. Knowing which datasets are referenced and cited in publications serves at least two purposes:
It provides a valuable signal about the importance and prominence of a dataset.
It gives dataset authors an easy place to see citations to their data and to get credit.
Indeed, we hope that highlighting publications that use the data will lead to a more healthy ecosystem of data citation. For the moment, our links to Google scholar are very approximate as we lack a good model on how people cite data. We try to go beyond DOIs to give somewhat better coverage, but the number of articles citing a dataset ends up being approximate. We hope to make more progress in this area in order to get a higher level of precision.
Search and Ranking of Results
When a user issues a query, we search through the corpus of datasets, in a way not unlike Google Search works over Web pages. Just like with any search, we need to determine whether a document is relevant for the query and then rank the relevant documents. Because there are no large-scale studies on how users search for datasets, as a first approximation, we rely on Google Web ranking. However, ranking datasets is different from ranking Web pages, and we add some additional signals that take into account the metadata quality, citations, and so on. As Dataset Search gets used more by our users and we understand better how users search for datasets, we hope that ranking will improve significantly.
A Better Open Data Ecosystem
We built Dataset Search in an attempt to create a tool that will positively impact the discoverability of data. The decision to rely on open standards (
schema.org
,
W3C DCAT
,
JSON-LD
, etc.) for markup is intentional, as Dataset Search can only be as good as the open-data ecosystem that it supports. As such, Google Dataset Search aims to support a strong open data ecosystem by encouraging:
Widespread adoption of open metadata formats to describe published data.
Further development of open metadata formats to describe more types of data and in more detail.
The culture of citing data the way we cite research publications, giving those who create and publish the data the credit that they deserve.
The development of tools that leverage this metadata to enable more discovery or better use of data.
The increased adoption of open metadata standards in conjunction with the continued development of Dataset Search (and, hopefully, other tools) should foster a healthier open data ecosystem where data is a first-class citizen of research.
So, Where is
Your
Dataset?
It is probably clear by now that Dataset Search is only as good as the metadata that exists on the Web pages for datasets. The most common answer to the question of why a specific dataset does not show up in our results is that the Web page for that dataset does not have any markup. Just pop that page into the
Structured Data Testing Tool
and you will see whether the markup is there. If you don't see any markup there, and you own the page, you can
add
it and if you don't own the page, you can ask the page owners to do it, which will make their page more easily discoverable by everyone.
We hope that the community finds
Dataset Search
useful, users make serendipitous discoveries and save time and scientists and journalists spend less time searching for data and more time using it.
Acknowledgements
We would like to thank Xiaomeng Ban, Dan Brickley, Lee Butler, Thomas Chen, Corinna Cortes, Kevin Espinoza, Archana Jain, Mike Jones, Kishore Papineni, Chris Sater, Gokhan Turhan, Shubin Zhao and Andi Vajda for their work on the project and all our partners, collaborators, and early adopters for their help.
Labels
2018
accessibility
ACL
ACM
Acoustic Modeling
Adaptive Data Analysis
ads
adsense
adwords
Africa
AI
Algorithms
Android
Android Wear
API
App Engine
App Inventor
April Fools
Art
Audio
Augmented Reality
Australia
Automatic Speech Recognition
Awards
BigQuery
Cantonese
Chemistry
China
Chrome
Cloud Computing
Collaboration
Compression
Computational Imaging
Computational Photography
Computer Science
Computer Vision
conference
conferences
Conservation
correlate
Course Builder
crowd-sourcing
CVPR
Data Center
Data Discovery
data science
datasets
Deep Learning
DeepDream
DeepMind
distributed systems
Diversity
Earth Engine
economics
Education
Electronic Commerce and Algorithms
electronics
EMEA
EMNLP
Encryption
entities
Entity Salience
Environment
Europe
Exacycle
Expander
Faculty Institute
Faculty Summit
Flu Trends
Fusion Tables
gamification
Gboard
Gmail
Google Accelerated Science
Google Books
Google Brain
Google Cloud Platform
Google Docs
Google Drive
Google Genomics
Google Maps
Google Photos
Google Play Apps
Google Science Fair
Google Sheets
Google Translate
Google Trips
Google Voice Search
Google+
Government
grants
Graph
Graph Mining
Hardware
HCI
Health
High Dynamic Range Imaging
ICLR
ICML
ICSE
Image Annotation
Image Classification
Image Processing
Inbox
India
Information Retrieval
internationalization
Internet of Things
Interspeech
IPython
Journalism
jsm
jsm2011
K-12
KDD
Keyboard Input
Klingon
Korean
Labs
Linear Optimization
localization
Low-Light Photography
Machine Hearing
Machine Intelligence
Machine Learning
Machine Perception
Machine Translation
Magenta
MapReduce
market algorithms
Market Research
Mixed Reality
ML
ML Fairness
MOOC
Moore's Law
Multimodal Learning
NAACL
Natural Language Processing
Natural Language Understanding
Network Management
Networks
Neural Networks
NeurIPS
Nexus
Ngram
NIPS
NLP
On-device Learning
open source
operating systems
Optical Character Recognition
optimization
osdi
osdi10
patents
Peer Review
ph.d. fellowship
PhD Fellowship
PhotoScan
Physics
PiLab
Pixel
Policy
Professional Development
Proposals
Public Data Explorer
publication
Publications
Quantum AI
Quantum Computing
renewable energy
Research
Research Awards
resource optimization
Robotics
schema.org
Search
search ads
Security and Privacy
Semantic Models
Semi-supervised Learning
SIGCOMM
SIGMOD
Site Reliability Engineering
Social Networks
Software
Sound Search
Speech
Speech Recognition
statistics
Structured Data
Style Transfer
Supervised Learning
Systems
TensorBoard
TensorFlow
TPU
Translate
trends
TTS
TV
UI
University Relations
UNIX
User Experience
video
Video Analysis
Virtual Reality
Vision Research
Visiting Faculty
Visualization
VLDB
Voice Search
Wiki
wikipedia
WWW
Year in Review
YouTube
Archive
2019
Feb
Jan
2018
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2017
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2016
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2015
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2014
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2013
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2012
Dec
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2011
Dec
Nov
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2010
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2009
Dec
Nov
Aug
Jul
Jun
May
Apr
Mar
Feb
Jan
2008
Dec
Nov
Oct
Sep
Jul
May
Apr
Mar
Feb
2007
Oct
Sep
Aug
Jul
Jun
Feb
2006
Dec
Nov
Sep
Aug
Jul
Jun
Apr
Mar
Feb
Feed
Follow @googleai
Give us feedback in our
Product Forums
.
