TREC 2018 News Track

Guidelines v1.0, 11 May 2018

Track coordinators: Shudong Huang, Ian Soboroff, Donna Harman (NIST)

Google group:!forum/trec-news-track


While news and newswire has been a common genre in IR experimentation for a very long time, the evaluation tasks in IR have rarely if ever supported the "news user" -- a consumer of news that is not an analyst.  According to a Pew Research study in 2016, roughly 38% of Americans get their news online, with the fraction increasing for younger consumers.

Moreover, since online delivery of news has shifted the focus away from the provider or publisher towards the story, news production has been dramatically democratized.  If everyone can produce professional looking news, then understanding the context and background of information becomes a harder task for the consumer.

This track is not about detecting "fake news".  Rather, we are envisioning new information access tools that help the user understand the context of a story, wherever they are reading it.  In conjunction with The Washington Post, we are developing tasks around how news is presented on the web and thinking about how to enhance that learning experience.  The larger question is, what roles can IR play in this new, noisy, adversarial online news domain?


The data for the track is the newly released TREC Washington Post Collection.  This is five years of articles, 2012 - 2017, and you can get it at no cost from NIST after completing the requisite usage agreement.  The data URL is

The files are "JSON-lines" format, that is, each document is a single long line of JSON.  The articles are broken into content paragraphs, with interspersed media such as images and videos referenced by URL.  Those URLs point back to the Washington Post website and should persist at those URLs for the foreseeable future.

There are quite a few duplicate documents in the collection, because at times the Post will republish an article, and the provenance history is not represented in the data.  For purposes of the track, we will furnish a list of documents which we consider to be duplicates.  For all tasks that return documents from the collection, you should only return a single instance of each "equivalence class" of duplicates, and they will all carry the same relevance judgments, so it will not matter which one you return.  However, duplicates in your result lists will be penalized by replacing them with a no-op document ID for evaluation.

Task 1: Background Linking

The goal background linking task is to develop systems that can help users contextualize news articles as they are reading them.  For example, news websites nearly always link to related articles in a sidebar, at the end of an article, from within the text of the article, or all three.  We want to look at a particular case for linking: given that the user is reading a specific article (the query article), recommend articles that this person should read next that are the most useful for providing context and background for the query article.

Note that links in the Washington Post article collection are not training data for this task.  In our conversations with the Post, their current practice is largely driven by the author of the article and does not follow any fixed guidelines or goal.  Hence, we are designing this task as a specific kind of news recommendation task that would be useful in any news reading context, including the Post's website.

From our conversations with Post journalists about linking for background and context, every author has their own guidelines in their head, but three common rules emerged:

  1. No wire service articles.  (That is, from Associated Press (AP), AFP, etc)
  2. No opinion or editorials.
  3. The list of links should be diverse.

The corpus does not contain any wire service articles, so (1) is taken care of for free.  For (2), we decree that articles from the "Opinion", "Letters to the Editor", or "The Post's View" sections, as labeled in the "kicker" field, are not relevant.  (3) is complicated as we are not sure we have a good understanding of diversity in the news recommendation context; resources permitting, we will pilot some annotations with the assessors which we hope will inform next year's version of the task.

The topics for the Common Core track are being used as starters for the background linking task topics: query articles are being selected based on documents found by the NIST assessors during Core track topic development.  It is currently TBD if topic numbers will be the same as in the Core track, but if not we will provide a mapping once the task is complete.

Results will be pooled and judged by NIST assessors on the following scale:

  1. The linked document provides little or no useful background information.
  2. The linked document provides some useful background or contextual information that would help the user understand the broader story context of the query article.
  3. The document provides significantly useful background ...
  4. The document provides essential useful background ...
  5. The document MUST appear in the sidebar otherwise critical context is missing.


Topics will mimic the standard TREC topic format:

num>Number: xxx </num>

"Docid" references the "id" field in the Washington Post corpus documents.  "Url" references the "article_url" field in the documents.  Both indicate the query article.  


Submissions should be standard TREC format, that is, trec_eval results file format:

1 Q0 2707e25a-cfaf-11e6-a87f-b917067331bb 1 37.5 myrun

1 Q0 513673ee-d003-11e6-b8a2-8c2a61b0436f 2 33.2 myrun


1 Q0 f8ded480-cdef-11e6-b8a2-8c2a61b0436f 99 0.5 myrun

2 Q0 350e3d74-cf94-11e6-a87f-b917067331bb 1 55.2 myrun


Systems may retrieve up to 100 documents per topic.  The first field is the topic id ("<num>" in the topic), the second field is a literal "Q0", the third field is the document ID of the linked document, the fourth field is the rank (ignored), the fifth field is the score, and the sixth field is the runtag.  Note that trec_eval sorts by descending score and breaks ties using document IDs.

The primary metric for the background linking task will be nDCG@5, where the gain value is 2^(r-1) where r is the relevance level from the scale above, and the zero relevance level contributes no gain.  Evaluation will use trec_eval so all traditional TREC measures will also be reported to a measurement depth of 100.


Query article: Love in the time of climate change: Grizzlies and polar bears are now mating (May 23, 2016)

This article describes and analyzes a phenomenon where grizzlies and polar bears are mating to create a new species known as pizzlies or grolars. It explains why this is happening and points out that it happens (or has happened) to other species as well. Articles along these lines are good background links. For example:

However, the following article is of less relevance and should be ranked lower because it’s not about interbreeding.

Task 2: Entity Ranking

In addition to providing links to articles that give the reader background or contextual information, journalists sometimes link mentions of concepts, artifacts, entities etc to internal or external pages with in depth information that will help the reader better understand the article. For this second task, entity ranking, we’ll provide a wikipedia dump, extract all entities from each query article that have entries in the wikipedia and ask the system to determine which entities are linkable for the given article and rank them in terms of “usefulness”. We will limit entity types to person, organization, location, geopolitical entity, and facility with proper names.

Consider this Washington post news article. Stanford's CoreNLP web service ( finds these named entities, among others:

A system that could automatically link "James Matthew Brady Jr." to a Wikipedia page about the event, San Antonio to a map location, and Los Zetas to a background document would be providing valuable further reading to the user.  In contrast, linking to Walmart's Wikipedia page or homepage would be less useful, and there is no reason to link the mention of the Washington Post in this article.  As with determinations of relevance, reasonable people might disagree about which entities are best to link, making this a good task for ranked retrieval systems.

(Note that there are also many more entities which are not so simple for systems to identify, such as "A federal grand jury", "immigration authorities", "federal prison", and "as many as 200 people".  For now, we are keeping things simple, but the end goal is automatic, importance-driven wikification of the article.)

There are three components to this task: identifying the entities to link, selecting the most important entities, and determining what to link them to.  The first and last tasks, called Entity Detection and Linking (EDL) in the Text Analysis Conference, are the subjects of active research in the NLP community.  For this task, we will focus on stage two: separating important entities from unimportant ones, for the purpose of making informational linkages for readers of the article.

Ranked entities will be pooled and judged by NIST assessors on the following scale:

  1. The linked entity provides little or no useful background information.
  2. The linked entity provides some useful background or contextual information that would help the user understand the broader story context of the query article.
  3. The entity link provides significantly useful background ...
  4. The entity link provides essential useful background ...
  5. The entity link MUST appear in the sidebar otherwise critical context is missing.


Topics will be in a modified TREC format, as follows:

num> Number: xxx </num>
docno> 4989ebfeb752e6b317d1ef3997b21a01 </docno>
id> xxx.1 </id>
mention>San Antonio</mention>

    <mention>Alamo city</mention>

The "entities" block is a sequence of one or more entities, each with an ID, the mention string, its location in the document, and a link into a Wikipedia dump provided for the track.


Systems will provide a ranking of the entities in the topic, in trec_eval format:

xxx q0 xxx.1 1 37.5 runtag


where the "docno" field should have an entity ID from the topic.


The primary metric for this task will be average precision of the entity ranking.  In the "real world" task a system would need to cut off the ranking so as not to link unimportant entities, but in this first iteration of the task we will not measure selecting the cutoff point.

Connection with the TREC 2018 Common Core Track

The Common Core track topics are the same as the topics for the Background Linking task in the News track.  We hope that this will provide an added incentive for participants in either track to also submit in the other.

Half of the topics come from past TREC test collections, and as such have existing relevance judgments in other collections (those based on the TREC/TIPSTER CDs, and/or AQUAINT, and/or New York TImes).  For those topics, participants are free to make use of this data, but have to indicate its use when they submit the run.

Note that the criteria for relevance and the task metrics are different between the two tracks.  It would be interesting to know if runs optimized for one task were also competitive in the other.


Manual, automatic, and feedback runs

When you submit your runs, you will be asked to indicate if the run is manual, automatic, or feedback.  An automatic run involves no manual intervention, but runs fully automatically from the topic file.  In contrast, manual runs can involve human intervention – including manual query formulation, manual relevance feedback, and reweighting/reranking by hand.  The third category, feedback, is to indicate otherwise automatic runs that make use of prior relevance judgments for the old topics.

Duplicate document handling

The Washington Post collection contains many duplicate documents, that is, documents which have verbatim identical JSON entries including the document ID.  Systems should take care to only return a document ID once per topic.

Additionally, there are duplicate documents with different document IDs but otherwise identical content.  We will release a list of "equivalence classes" indicating the document which should subsume the other copies, and a Python script to automatically prune the duplicates from the collection.  Systems that return duplicate documents will be penalized by having the docids remapped to "bogus" ids which are by definition not relevant.

External resources

We will provide a Wikipedia dump from August 20, 2017, which coincides with the end of the epoch of the Washington Post collection.  This dump will be formatted identically to dumps used in the CAR track.  Entity links in Task 2 will be with respect to this collection.  A checkbox on the run submission form will ask if you made use of this dump.

Additional Examples

Topic 321: Women in Parliaments

Query article: Another way Britain’s vote made history: More women than ever before were just elected (June 9, 2017)

Background links:

This is WaPo’s initial report on May’s call for a June snap general election. The query article is focused on record number of female MPs elected but doesn’t provide much information on the election itself. So this article provides significant background to the reader.

The name “Emily Wilding Davison” has a prominent role in the query article. As it happens, there was a movie made in 2015 about the women’s rights movement in the early 20th century and the movie’s climax is based on the real life story of Emily Wilding Davison.


*Note that these entities do not have wikipedia entries and thus will not be included in the list to be ranked by systems.

The most important entity for this article is undoubtedly “Emily Wilding Davison”. A reader might also be interested in knowing more about the UK political system, and so “House of Commons”, “Labour Party”, and “Toy” should also be high. Linking “UK” or “Theresa May” is probably not very informative for most readers.

Topic 809: Protect Earth from Asteroids

Query article: Europe will send a rover to Mars but won’t protect Earth from an asteroid (December 5, 2016)

This article is about the European Space Agency’s success of securing funds to send a rover to Mars and its failure to secure funding to survey a near-Earth asteroid in order to understand how to deflect an asteroid coming towards the Earth.

Background links:

The ExoMars lander’s crash landing was a setback for ESA’s space programs.


*Note that these entities do not have wikipedia entries and thus will not be included in the list to be ranked by systems.

Key dates

Guidelines released: May 2018

Background linking topics released: July 20

Entity ranking topics released: July 27

All runs due: August 21

TREC: November 14-16, 2018