Argument Retrieval for Comparative Questions 2020

Formerly named: Comparative Argument Retrieval


  • Task: Given a comparative question, retrieve and rank documents from the ClueWeb12 that help to answer the comparative question.
  • Input: [api] [other]
  • Submission: [submit]


The goal of Task 2 is to support users facing some choice problem from "everyday life". Given a comparative question, the task is to retrieve and rank documents from the ClueWeb12 that help to answer the comparative question.


The topics for Tasks 2 will be send to each team via email upon completed registration. The topics will be provided as XML files.

Example topic for Task 2:

<title>Which is better, laptop or desktop?</title>
<description>A user wants to buy a new PC but has no prior preferences. They want to find arguments that show in what personal situation what kind of machine is preferable. This can range from situations like frequent traveling where a mobile device is to be favored to situations of a rather "stationary" gaming desktop PC.</description>
<narrative>Highly relevant documents will describe what the major similarities and dissimilarities of laptops and desktops are along with the respective advantages and disadvantages for specific usage scenarios. A comparison of the technical and architectural characteristics without a personal opinion, recommendation or pros/cons is not relevant.</narrative>

The corpus for Task 2 is the ClueWeb12 corpus; you may index the ClueWeb12 with your favorite retrieval system. To ease participation, you may also directly use the ChatNoir search engine's API for a baseline retrieval. You will receive credentials to access the ChatNoir API upon a completed registration.

Other data for this task are the topics, quality judgements, and participant runs. [download]


Be sure to retrieve good ''strong'' arguments. Our human assessors will label the retrieved documents manually, both for their general topical relevance and for the rhetorical quality, i.e., "well-writtenness" of the document: (1) whether the text has a good style of speech (formal language is preferred over informal), (2) whether the text has a proper sentence structure and is easy to read, (3) whether it includes profanity, has typos, and makes use of other detrimental style choices.


We encourage participants to use TIRA for their submissions to allow for a better reproducibility. Please also have a look at our TIRA quickstart—in case of problems we will be able to assist you. Even though the preferred way of run submission is TIRA, in case of problems you may also submit runs via email. We will try to quickly review your TIRA or email submissions and provide feedback.

Runs may be either automatic or manual. An automatic run does not use the topic descriptions or narratives and must not "manipulate" the topic titles via manual intervention. A manual run is anything that is not an automatic run. Upon submission, please let us know which of your runs are manual. For each topic, include up to 1,000 retrieved documents.

The submission format for the task will follow the standard TREC format:

qid Q0 doc rank score tag
  • qid: The topic number.
  • Q0: Unused, should always be Q0.
  • doc: The document ID (the official ID) returned by your system for the topic qid.
  • rank: The rank the document is retrieved at.
  • score: The score (integer or floating point) that generated the ranking. The score must be in descending (non-increasing) order. It is important to handle tied scores (trec_eval sorts documents by the score values and not your rank values).
  • tag: A tag that identifies your group and the method you used to produce the run.
The fields should be separated by a whitespace. The individual columns' widths are not restricted (i.e., score can be an arbitrary precision that has no ties) but it is important to include all columns and to separate them with a whitespace.

An example run for Task 2 is:
1 Q0 clueweb12-en0010-85-29836 1 17.89 myGroupMyMethod
1 Q0 clueweb12-en0010-86-00457 2 16.43 myGroupMyMethod
1 Q0 clueweb12-en0010-86-09202 3 16.42 myGroupMyMethod

TIRA Quickstart

Participants have to upload (through SSH or RDP) their retrieval models in a dedicated TIRA virtual machine, so that their runs can be reproduced and so that they can be easily applied to different data (of same format) in the future. You can find host ports for your VM in the web interface, same login as to your VM. If you cannot connect to your VM, please make sure it is powered on: you can check and power on your machine in the web interface.

Your software is expected to accept two arguments:

  • An input directory (named $inputDataset in TIRA). This input directory contains a topics.xml file hat contains the topics for which documents should be retrieved.
  • An output directory (named $outputDir in TIRA). Your software should create a standard trec run file in $outputDir/run.txt.

Your Software can use the API of the search engine ChatNoir to produce the run file.

As soon as your Software is installed in your VM, you can register it in TIRA.

Assume that your software is started with a bash script in your home directory called which expects an argument -i specifying the input directory, and an argument -o specifying the output directory. Click on "Add software" and specify the command -i $inputDataset -o $outputDir. The other fields can stay with default settings.

Overview of the software configuration in TIRA.

Click on "Run" to execute your software in TIRA. Note that your VM will not be accessible while your system is running – it will be “sandboxed”, detached from the internet, and after the run the state of the VM before the run will be restored. Your run will be reviewed and evaluated by the organizers.

NOTE: By submitting your software you retain full copyrights. You agree to grant us usage rights for evaluation of the corresponding data generated by your software. We agree not to share your software with a third party or use it for any purpose other than research.

Once the run of your system completes, please also run the evaluator on the output of your system to verify that your output is a valid submission. These are two separate actions and both should be invoked through the web interface of TIRA. You don’t have to install the evaluator in your VM. It is already prepared in TIRA. You should see it in the web interface, under your software, labeled “Evaluator”. Before clicking the “Run” button, you will use a drop-down menu to select the “Input run”, i.e. one of the completed runs of your system. The output files from the selected run will be evaluated.

Overview of the software evaluation in TIRA.

You can see and download STDOUT and STDERR as well as the outputs of your system. In the evaluator run you will see only STDOUT and STDERR, which will tell you if one or more of your output files is not valid. If you think something went wrong with your run, send us an e-mail. Additionally, we review your submissions and contact you on demand.

You can register more than one system (“software/ model”) per virtual machine using the web interface. TIRA gives systems automatic names “Software 1”, “Software 2” etc. You can perform several runs per system.


Runs of each team [qrels]
team results
Tag nDCG@5
Bilbo Baggins ul_t2_voelkerschlacht 0.580
Puss in Boots (baseline) 0.568
Inigo Montoya MLU_Gruppe_2 0.567
Katana MyBaselineFilterResponse 0.564
Katana Baseline_CAM_OBJ 0.553
Frodo Baggins t2_bach_default_old 0.542
Frodo Baggins ir_t2_bach 0.450
Zorro UvATask2SVM 0.446
Katana myBertSimilarity 0.404
Katana MethodAttentionFilterResponse 0.223
Katana ULMFIT_LSTM 0.200

Task Committee