Skip to content

Retrieval Axioms

Constraints on document rankings for a query

Retrieval axioms compare two documents \(d_1\), \(d_2\) for a query \(q\) and implement the interface Axiom[Query, Document]. The original formulations of most axioms are restricted to artificial settings, e.g., single-term queries or documents of exactly the same length. Following Hagen et al. [Hagen et al., 2016] and Völske et al. [Völske et al., 2021], the implementations in ir_axioms incorporate an axiom's formalized idea while also making it applicable in practical settings [Bondarenko et al., 2022]: they are reformulated to work for arbitrary queries, to express pairwise preferences, and they include parameters to relax or strengthen pre- and filter conditions (e.g., a relative margin_fraction within which values are considered equal).

The API reference documents all classes and parameters; the integrations guide shows how to apply the axioms to a retrieval index.

Below, each axiom is listed with its original intuition and formulation, followed by the changes made in ir_axioms. In the formulations, \(\mathrm{tf}(t, d)\) denotes the frequency of term \(t\) in document \(d\), \(|d|\) the document length, \(\mathrm{idf}(t)\) the inverse document frequency of \(t\), and \(\mathrm{sim}(t, t')\) a term similarity.

Axioms requiring a retrieval index

Axioms using collection statistics (TFC3, M-TDC, LEN-M-TDC, ASPECT-REG) require an index, provided by the PyTerrier or Pyserini integration. LB1 requires retrieval scores, and ORIG and ORACLE require ranks/scores and relevance labels, respectively (see utility axioms).

Term Frequency

TFC1

TFC1 Tfc1Axiom — "Prefer documents with more query term occurrences." [Fang et al., 2004]

Original formulation
Given \(q = \{t\}\) and \(d_1, d_2\) with \(|d_1| = |d_2|\): if \(\mathrm{tf}(t, d_1) > \mathrm{tf}(t, d_2)\), then \(d_1 >_\text{TFC1} d_2\).
Changes in ir_axioms
Term frequencies are summed over all query terms, to allow queries with more than one term. Term frequency sums within a relative margin are considered equal, i.e., the inequality requires at least a 10 % difference [Völske et al., 2021].
Parameters
margin_fraction=0.1 (term frequency sum margin), precondition=LEN() (document length precondition with 10 % margin).

TFC2

TFC2 — "Additional query term occurrences yield smaller retrieval score improvements." [Fang et al., 2011]

Not implemented, because the axiom compares score differences of three documents and does not induce a pairwise preference.

TFC3

TFC3 Tfc3Axiom — "Prefer documents with occurrences of more query terms." [Fang et al., 2011]

Original formulation
Given \(q = \{t_1, t_2\}\) and \(d_1, d_2\) with \(|d_1| = |d_2|\) and \(\mathrm{idf}(t_1) = \mathrm{idf}(t_2)\): if \(\mathrm{tf}(t_1, d_2) = \mathrm{tf}(t_1, d_1) + \mathrm{tf}(t_2, d_1)\) and \(\mathrm{tf}(t_2, d_2) = 0\) and \(\mathrm{tf}(t_1, d_1) \neq 0\) and \(\mathrm{tf}(t_2, d_1) \neq 0\), then \(d_1 >_\text{TFC3} d_2\).
Changes in ir_axioms
Term discrimination uses the inverse document frequency with a relative margin. Preferences are counted over all pairs of query terms, to allow queries with more than two terms [Völske et al., 2021].
Parameters
margin_fraction=0.1 (IDF margin), precondition=LEN().

TDC and M-TDC

M_TDC ModifiedTdcAxiom — "Prefer documents with more discriminative query terms."

Original formulation (TDC)
Given \(q = \{t_1, t_2\}\) and \(d_1, d_2\) with \(|d_1| = |d_2|\), let \(d\) be some document. If \(\mathrm{idf}(t_1) > \mathrm{idf}(t_2)\) and \(t_1 \in d_1\), \(t_2 \notin d_1\), \(t_1 \notin d_2\), \(t_2 \in d_2\), then \(d \circ d_1 >_\text{TDC} d \circ d_2\) [Fang et al., 2004; Fang et al., 2011].
Changes in ir_axioms
The original TDC is not implemented. Instead, ir_axioms implements the modified TDC by Shi et al. [Shi et al., 2005], which compares documents with the same total query term frequency (but differently distributed over the query terms) and, for each pair of query terms with different IDF, gives a point to the document with more occurrences of the more discriminative term. The document with more points is preferred.
Variants
LEN_M_TDC LenModifiedTdcAxiom: M-TDC with an additional document length precondition (precondition=LEN()).

Document Length

LNC1

LNC1 Lnc1Axiom — "Penalize longer documents for non-relevant terms." [Fang et al., 2004]

Original formulation
Given \(q\) and \(d_1, d_2\), let \(t \notin q\) and \(t'\) denote some arbitrary terms. If \(\mathrm{tf}(t, d_1) + 1 = \mathrm{tf}(t, d_2)\) and \(\mathrm{tf}(t', d_1) = \mathrm{tf}(t', d_2)\) for all \(t' \neq t\), then \(d_1 \geq_\text{LNC1} d_2\).
Changes in ir_axioms
If all query terms occur equally often in both documents (within a relative margin), prefer the shorter document. The margin allows for relative term frequency implementations.
Parameters
margin_fraction=0.1.

LNC2

LNC2 — "Do not prefer shorter documents when the matched query term ratio is the same." [Fang et al., 2004]

Not implemented, because the precondition (\(d_1\) being a \(c\)-fold concatenation of \(d_2\)) practically never holds for real documents.

TF-LNC

TF_LNC TfLncAxiom — "Reward additional query terms more than document length is penalized." [Fang et al., 2004]

Original formulation
Given \(q = \{t\}\) and \(d_1, d_2\): if \(\mathrm{tf}(t, d_1) > \mathrm{tf}(t, d_2)\) and \(|d_1| = |d_2| + \mathrm{tf}(t, d_1) - \mathrm{tf}(t, d_2)\), then \(d_1 >_\text{TF-LNC} d_2\).
Changes in ir_axioms
For each query term, if both documents have the same length when ignoring that term, the document with more occurrences of the term gets a point. Points are counted over all query terms, to allow queries with more terms.

Lower-Bounding Term Frequency

LB1

LB1 Lb1Axiom — "Do not override the term presence–absence gap with length normalization." [Lv and Zhai, 2011]

Original formulation
Given \(t \in q\) and \(d_1, d_2\) with \(\mathrm{score}(q \setminus \{t\}, d_1) = \mathrm{score}(q \setminus \{t\}, d_2)\): if \(\mathrm{tf}(t, d_1) > 0\) and \(\mathrm{tf}(t, d_2) = 0\), then \(d_1 >_\text{LB1} d_2\).
Changes in ir_axioms
Following Hagen et al. [Hagen et al., 2016], uses the documents' retrieval scores (with 10 % softening) instead of the scores without term \(t\). Prefers the document that contains a query term that the other document does not contain.
Parameters
margin_fraction=0.1 (score margin). Requires documents with a score.

LB2

LB2 — "Repeated query term occurrence is less important than the first occurrence." [Lv and Zhai, 2011]

Not implemented, because the axiom requires modifying documents (adding/removing terms) and does not induce a practical pairwise preference.

Query Aspects

REG

REG RegAxiom — "Prefer documents covering more different query aspects." [Zheng and Fang, 2010]

Original formulation
Given \(q = \{t_1, t_2, t_3\}\) and \(d_1, d_2\) with \(|d_1| = |d_2|\), \(\mathrm{idf}(t_2) = \mathrm{idf}(t_3)\), \(\mathrm{sim}(t_1, t_2) > \mathrm{sim}(t_1, t_3)\), and \(\mathrm{sim}(t_1, t_2) > \mathrm{sim}(t_2, t_3)\): if \(\mathrm{tf}(t_1, d_1) = \mathrm{tf}(t_1, d_2) > 0\), \(\mathrm{tf}(t_3, d_1) = \mathrm{tf}(t_2, d_2) > 0\), and \(\mathrm{tf}(t_2, d_1) = \mathrm{tf}(t_3, d_2) = 0\), then \(d_1 >_\text{REG} d_2\).
Changes in ir_axioms
Determines the query term(s) with the minimum average similarity to the other query terms (i.e., the most "different" aspect) and prefers the document with more occurrences of these terms, as described by Völske et al. [Völske et al., 2021]. The term similarity is configurable (WordNet synonym sets by default, fastText if installed).
Parameters
precondition=LEN().
Variants
ANTI_REG AntiRegAxiom: uses the query term(s) with the maximum average similarity instead, as in the modification of REG by Hagen et al. [Hagen et al., 2016].
ASPECT_REG AspectRegAxiom: follows the query aspect clustering of Zheng and Fang [Zheng and Fang, 2010] (requires equally discriminative query terms) and prefers documents covering at least one of the query aspects.

AND

AND AndAxiom — "Prefer documents containing all query terms." [Wu and Fang, 2012]

Original formulation
Given \(q = \{t_1, t_2\}\) with \(\mathrm{idf}(t_1) \geq \mathrm{idf}(t_2)\): if \(\mathrm{tf}(t_1, d_1) = 1\), \(\mathrm{tf}(t_2, d_1) = 1\), \(\mathrm{tf}(t_1, d_2) > 1\), and \(\mathrm{tf}(t_2, d_2) = 0\), then \(d_1 >_\text{AND} d_2\).
Changes in ir_axioms
Prefers the document that contains all query terms if the other document does not, for queries of arbitrary length [Hagen et al., 2016].
Variants
LEN_AND LenAndAxiom: AND with a document length precondition (precondition=LEN()).
M_AND ModifiedAndAxiom: prefers the document that contains a larger subset of the query terms.
LEN_M_AND LenModifiedAndAxiom: M-AND with a document length precondition.

DIV

DIV DivAxiom — "Prefer documents that are less redundant with the query." [Gollapudi and Sharma, 2009]

Changes in ir_axioms
The diversity axioms of Gollapudi and Sharma characterize result-set diversification functions and do not express pairwise document preferences. Following Hagen et al. [Hagen et al., 2016], ir_axioms reformulates the idea as a pairwise preference: prefer the document with the lower vocabulary overlap (Jaccard coefficient) with the query.
Variants
LEN_DIV LenDivAxiom: DIV with a document length precondition (precondition=LEN()).

Semantic Similarity

STMC1

STMC1 Stmc1Axiom — "Prefer documents with terms more similar to query terms." [Fang and Zhai, 2006]

Original formulation
Given \(q = \{t\}\), \(d_1 = \{t_1\}\), and \(d_2 = \{t_2\}\) with \(t \neq t_1\), \(t \neq t_2\): if \(\mathrm{sim}(t, t_1) > \mathrm{sim}(t, t_2)\), then \(d_1 >_\text{STMC1} d_2\).
Changes in ir_axioms
Following Hagen et al. [Hagen et al., 2016], compares the average similarity of all document terms to all query terms, to allow arbitrary queries and documents. The term similarity is configurable (WordNet synonym sets by default, fastText if installed).

STMC2

STMC2 Stmc2Axiom — "Do not reward similar terms more than exact matches." [Fang and Zhai, 2006]

Original formulation
Given \(q = \{t\}\) and \(d_1, d_2\) with \(|d_1| = 1\), \(|d_2| = c > 0\), and a term \(t'\) with \(\mathrm{sim}(t, t') > 0\): if \(\mathrm{tf}(t, d_1) = 1\) and \(\mathrm{tf}(t', d_2) = c\), then \(d_1 \geq_\text{STMC2} d_2\).
Changes in ir_axioms
Following Hagen et al. [Hagen et al., 2016], given the most similar pair of a query term \(t\) and a non-query term \(t'\), prefer the document matching \(t\) exactly if the other document's frequency of \(t'\) relative to its length is similar (within a margin) to the first document's frequency of \(t\) relative to its length.
Parameters
margin_fraction=0.2.

Term Proximity

The proximity axioms were proposed by Hagen et al. [Hagen et al., 2016], inspired by the proximity measures studied by Tao and Zhai [Tao and Zhai, 2007]. Tao and Zhai's own constraints describe properties of distance measures and do not induce ranking preferences, so Hagen et al. derived the following pairwise axioms from the measures instead. All of them require that both documents contain the same subset of query terms (PROX1–PROX3) or all query terms (PROX4–PROX5).

PROX1

PROX1 Prox1Axiom — "Prefer documents with shorter distance between query term pairs."

Given \(q\) and \(d_1, d_2\) with \(d_1 \cap q = d_2 \cap q\), let \(P = \{(t, t') : t, t' \in q, t \neq t'\}\) and \(\delta(d, t, t')\) the average number of words between \(t\) and \(t'\) in \(d\). If \(\sum_{(t, t') \in P} \delta(d_1, t, t') < \sum_{(t, t') \in P} \delta(d_2, t, t')\), then \(d_1 >_\text{PROX1} d_2\).

PROX2

PROX2 Prox2Axiom — "Prefer documents with earlier query term occurrences."

Given \(q\) and \(d_1, d_2\) with \(d_1 \cap q = d_2 \cap q\), let \(\mathrm{first}(t, d)\) denote the position of the first occurrence of \(t\) in \(d\). If \(\sum_{t \in q} \mathrm{first}(t, d_1) < \sum_{t \in q} \mathrm{first}(t, d_2)\), then \(d_1 >_\text{PROX2} d_2\).

PROX3

PROX3 Prox3Axiom — "Prefer documents where the query occurs earlier as a phrase."

Given \(q\) and \(d_1, d_2\) with \(d_1 \cap q = d_2 \cap q\), let \(\tau(d, q)\) denote the first position of the whole query \(q\) as one phrase in \(d\) (\(\infty\) if \(q\) does not occur as a phrase). If \(\tau(d_1, q) < \tau(d_2, q)\), then \(d_1 >_\text{PROX3} d_2\).

PROX4

PROX4 Prox4Axiom — "Prefer documents that contain all query terms in a shorter substring."

Given \(q\) and \(d_1, d_2\) with \(d_1 \cap q = d_2 \cap q = q\), let \(\omega(d, q)\) denote the length of the shortest substring of \(d\) that contains all query terms. If \(\omega(d_1, q) < \omega(d_2, q)\), then \(d_1 >_\text{PROX4} d_2\). Following Hagen et al., \(\omega(d, q)\) is the pair of the number of non-query words within the closest grouping of all query terms and the frequency of this gap, so ties are broken by the number of such shortest substrings.

PROX5

PROX5 Prox5Axiom — "Prefer documents where the query terms are closer together on average."

Given \(q\) and \(d_1, d_2\) with \(d_1 \cap q = d_2 \cap q = q\), let \(\bar{s}(d, q)\) denote the average length of the shortest substrings of \(d\) that contain all query terms (averaged over all occurrences of query terms in \(d\)). If \(\bar{s}(d_1, q) < \bar{s}(d_2, q)\), then \(d_1 >_\text{PROX5} d_2\).

Argumentativeness

The argumentativeness axioms aim at queries that probably require argumentative results (e.g., "mercy killing") [Bondarenko et al., 2018; Bondarenko et al., 2019]. They identify argumentative units (premises and claims) with the TARGER argument mining API and apply a document length precondition by default (precondition=LEN()). Later work extended them for comparative questions [Reimer et al., 2022] and argument retrieval with embeddings [Heinrich et al., 2025] (see related axioms).

ArgUC

ArgUC ArgumentativeUnitsCountAxiom — "Prefer more argumentative units." [Bondarenko et al., 2022; Reimer et al., 2022]

Intuition
Favors documents with more argument units, i.e., premises and claims [Bondarenko et al., 2022].

QTArg

QTArg QueryTermOccurrenceInArgumentativeUnitsAxiom — "Prefer more query terms in argumentative units." [Bondarenko et al., 2022; Reimer et al., 2022]

Intuition
Favors documents where the query terms appear in (i.e., close to) the argument units [Bondarenko et al., 2022].

QTPArg

QTPArg QueryTermPositionInArgumentativeUnitsAxiom — "Prefer earlier query terms in argumentative units." [Bondarenko et al., 2022; Reimer et al., 2022]

Intuition
Favors documents where the first occurrence of a query term in an argumentative unit is closer to the beginning of the document, based on the general observation that query terms occur "earlier" in relevant documents [Troy and Zhang, 2007; Mitra et al., 2017].
Parameters
penalty=100000: penalty for the average query term position if a query term is not found in any argumentative unit (None to use the maximum length of the two documents).

aSL

aSL AverageSentenceLengthAxiom (alias: aSLDoc) — "Prefer passages with 12–20 words per sentence." [Bondarenko et al., 2022; Reimer et al., 2022]

Intuition
Favors more "readable" documents [Bondarenko et al., 2022], based on the general observation for text readability and good writing style [Markel, 2010; Newell, 2014].
Parameters
min_sentence_length=12, max_sentence_length=20.

References

Alexander Bondarenko, Michael Völske, Alexander Panchenko, Chris Biemann, Benno Stein, and Matthias Hagen. Webis at TREC 2018: Common Core Track. In Proceedings of the Twenty-Seventh Text REtrieval Conference, TREC 2018, Gaithersburg, Maryland, USA, November 14-16, 2018, 2018. National Institute of Standards and Technology (NIST). []
@inproceedings{bondarenko2018webis,
  author       = {Alexander Bondarenko and
                  Michael V{\"{o}}lske and
                  Alexander Panchenko and
                  Chris Biemann and
                  Benno Stein and
                  Matthias Hagen},
  title        = {Webis at {TREC} 2018: Common Core Track},
  booktitle    = {Proceedings of the Twenty-Seventh Text REtrieval Conference, {TREC}
                  2018, Gaithersburg, Maryland, USA, November 14-16, 2018},
  series       = {{NIST} Special Publication},
  volume       = {500-331},
  publisher    = {National Institute of Standards and Technology {(NIST)}},
  year         = {2018},
  url          = {https://trec.nist.gov/pubs/trec27/papers/Webis-CC.pdf}
}
Alexander Bondarenko, Maik Fröbe, Vaibhav Kasturia, Michael Völske, Benno Stein, and Matthias Hagen. Webis at TREC 2019: Decision Track. In Proceedings of the Twenty-Eighth Text REtrieval Conference, TREC 2019, Gaithersburg, Maryland, USA, November 13-15, 2019, 2019. National Institute of Standards and Technology (NIST). []
@inproceedings{bondarenko2019webis,
  author       = {Alexander Bondarenko and
                  Maik Fr{\"{o}}be and
                  Vaibhav Kasturia and
                  Michael V{\"{o}}lske and
                  Benno Stein and
                  Matthias Hagen},
  title        = {Webis at {TREC} 2019: Decision Track},
  booktitle    = {Proceedings of the Twenty-Eighth Text REtrieval Conference, {TREC}
                  2019, Gaithersburg, Maryland, USA, November 13-15, 2019},
  series       = {{NIST} Special Publication},
  volume       = {1250},
  publisher    = {National Institute of Standards and Technology {(NIST)}},
  year         = {2019},
  url          = {https://trec.nist.gov/pubs/trec28/papers/Webis.D.pdf}
}
Alexander Bondarenko, Maik Fröbe, Jan Heinrich Reimer, Benno Stein, Michael Völske, and Matthias Hagen. Axiomatic Retrieval Experimentation with ir_axioms. In SIGIR '22: The 45th International ACM SIGIR Conference on Research and Development in Information Retrieval, Madrid, Spain, July 11-15, 2022, pages 3131–3140, 2022. ACM. [] [doi]
@inproceedings{bondarenko2022axiomatic,
  author       = {Alexander Bondarenko and
                  Maik Fr{\"{o}}be and
                  Jan Heinrich Reimer and
                  Benno Stein and
                  Michael V{\"{o}}lske and
                  Matthias Hagen},
  title        = {Axiomatic Retrieval Experimentation with ir{\_}axioms},
  booktitle    = {{SIGIR} '22: The 45th International {ACM} {SIGIR} Conference on Research
                  and Development in Information Retrieval, Madrid, Spain, July 11-15, 2022},
  pages        = {3131--3140},
  publisher    = {{ACM}},
  year         = {2022},
  url          = {https://doi.org/10.1145/3477495.3531743},
  doi          = {10.1145/3477495.3531743}
}
Hui Fang, Tao Tao, and ChengXiang Zhai. A formal study of information retrieval heuristics. In SIGIR 2004: Proceedings of the 27th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, Sheffield, UK, July 25-29, 2004, pages 49–56, 2004. ACM. [] [doi]
@inproceedings{fang2004formal,
  author       = {Hui Fang and
                  Tao Tao and
                  ChengXiang Zhai},
  title        = {A formal study of information retrieval heuristics},
  booktitle    = {{SIGIR} 2004: Proceedings of the 27th Annual International {ACM} {SIGIR}
                  Conference on Research and Development in Information Retrieval,
                  Sheffield, UK, July 25-29, 2004},
  pages        = {49--56},
  publisher    = {{ACM}},
  year         = {2004},
  url          = {https://doi.org/10.1145/1008992.1009004},
  doi          = {10.1145/1008992.1009004}
}
Hui Fang and ChengXiang Zhai. Semantic term matching in axiomatic approaches to information retrieval. In SIGIR 2006: Proceedings of the 29th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, Seattle, Washington, USA, August 6-11, 2006, pages 115–122, 2006. ACM. [] [doi]
@inproceedings{fang2006semantic,
  author       = {Hui Fang and
                  ChengXiang Zhai},
  title        = {Semantic term matching in axiomatic approaches to information retrieval},
  booktitle    = {{SIGIR} 2006: Proceedings of the 29th Annual International {ACM} {SIGIR}
                  Conference on Research and Development in Information Retrieval,
                  Seattle, Washington, USA, August 6-11, 2006},
  pages        = {115--122},
  publisher    = {{ACM}},
  year         = {2006},
  url          = {https://doi.org/10.1145/1148170.1148193},
  doi          = {10.1145/1148170.1148193}
}
Hui Fang, Tao Tao, and ChengXiang Zhai. Diagnostic Evaluation of Information Retrieval Models. ACM Trans. Inf. Syst., 29 (2) : 7:1–7:42, 2011. [] [doi]
@article{fang2011diagnostic,
  author       = {Hui Fang and
                  Tao Tao and
                  ChengXiang Zhai},
  title        = {Diagnostic Evaluation of Information Retrieval Models},
  journal      = {{ACM} Trans. Inf. Syst.},
  volume       = {29},
  number       = {2},
  pages        = {7:1--7:42},
  year         = {2011},
  url          = {https://doi.org/10.1145/1961209.1961210},
  doi          = {10.1145/1961209.1961210}
}
Sreenivas Gollapudi and Aneesh Sharma. An axiomatic approach for result diversification. In Proceedings of the 18th International Conference on World Wide Web, WWW 2009, Madrid, Spain, April 20-24, 2009, pages 381–390, 2009. ACM. [] [doi]
@inproceedings{gollapudi2009axiomatic,
  author       = {Sreenivas Gollapudi and
                  Aneesh Sharma},
  title        = {An axiomatic approach for result diversification},
  booktitle    = {Proceedings of the 18th International Conference on World Wide Web,
                  {WWW} 2009, Madrid, Spain, April 20-24, 2009},
  pages        = {381--390},
  publisher    = {{ACM}},
  year         = {2009},
  url          = {https://doi.org/10.1145/1526709.1526761},
  doi          = {10.1145/1526709.1526761}
}
Matthias Hagen, Michael Völske, Steve Göring, and Benno Stein. Axiomatic Result Re-Ranking. In Proceedings of the 25th ACM International Conference on Information and Knowledge Management, CIKM 2016, Indianapolis, IN, USA, October 24-28, 2016, pages 721–730, 2016. ACM. [] [doi]
@inproceedings{hagen2016axiomatic,
  author       = {Matthias Hagen and
                  Michael V{\"{o}}lske and
                  Steve G{\"{o}}ring and
                  Benno Stein},
  title        = {Axiomatic Result Re-Ranking},
  booktitle    = {Proceedings of the 25th {ACM} International Conference on Information
                  and Knowledge Management, {CIKM} 2016, Indianapolis, IN, USA, October
                  24-28, 2016},
  pages        = {721--730},
  publisher    = {{ACM}},
  year         = {2016},
  url          = {https://doi.org/10.1145/2983323.2983704},
  doi          = {10.1145/2983323.2983704}
}
Maximilian Heinrich, Marvin Vogel, Alexander Bondarenko, Matthias Hagen, and Benno Stein. Axiomatic Re-Ranking for Argument Retrieval. In Proceedings of the 48th International ACM SIGIR Conference on Research and Development in Information Retrieval, SIGIR 2025, Padua, Italy, July 13-18, 2025, pages 2864–2869, 2025. ACM. [] [doi]
@inproceedings{heinrich2025axiomatic,
  author       = {Maximilian Heinrich and
                  Marvin Vogel and
                  Alexander Bondarenko and
                  Matthias Hagen and
                  Benno Stein},
  title        = {Axiomatic Re-Ranking for Argument Retrieval},
  booktitle    = {Proceedings of the 48th International {ACM} {SIGIR} Conference on
                  Research and Development in Information Retrieval, {SIGIR} 2025, Padua,
                  Italy, July 13-18, 2025},
  pages        = {2864--2869},
  publisher    = {{ACM}},
  year         = {2025},
  url          = {https://doi.org/10.1145/3726302.3730169},
  doi          = {10.1145/3726302.3730169}
}
Yuanhua Lv and ChengXiang Zhai. Lower-bounding term frequency normalization. In Proceedings of the 20th ACM Conference on Information and Knowledge Management, CIKM 2011, Glasgow, United Kingdom, October 24-28, 2011, pages 7–16, 2011. ACM. [] [doi]
@inproceedings{lv2011lower,
  author       = {Yuanhua Lv and
                  ChengXiang Zhai},
  title        = {Lower-bounding term frequency normalization},
  booktitle    = {Proceedings of the 20th {ACM} Conference on Information and Knowledge
                  Management, {CIKM} 2011, Glasgow, United Kingdom, October 24-28, 2011},
  pages        = {7--16},
  publisher    = {{ACM}},
  year         = {2011},
  url          = {https://doi.org/10.1145/2063576.2063584},
  doi          = {10.1145/2063576.2063584}
}
Mike Markel. Technical Communication. 2010. Bedford/St. Martin's. []
@book{markel2010technical,
  author       = {Mike Markel},
  title        = {Technical Communication},
  edition      = {9th},
  publisher    = {Bedford/St. Martin's},
  year         = {2010},
  note         = {Not indexed in DBLP}
}
Bhaskar Mitra, Fernando Diaz, and Nick Craswell. Learning to Match using Local and Distributed Representations of Text for Web Search. In Proceedings of the 26th International Conference on World Wide Web, WWW 2017, Perth, Australia, April 3-7, 2017, pages 1291–1299, 2017. ACM. [] [doi]
@inproceedings{mitra2017learning,
  author       = {Bhaskar Mitra and
                  Fernando Diaz and
                  Nick Craswell},
  title        = {Learning to Match using Local and Distributed Representations of Text
                  for Web Search},
  booktitle    = {Proceedings of the 26th International Conference on World Wide Web,
                  {WWW} 2017, Perth, Australia, April 3-7, 2017},
  pages        = {1291--1299},
  publisher    = {{ACM}},
  year         = {2017},
  url          = {https://doi.org/10.1145/3038912.3052579},
  doi          = {10.1145/3038912.3052579}
}
Chris Newell. Editing Tip: Sentence Length. Online, 2014. []
@misc{newell2014editing,
  author       = {Chris Newell},
  title        = {Editing Tip: Sentence Length},
  year         = {2014},
  howpublished = {Online},
  note         = {Not indexed in DBLP; reference as given in the ir{\_}axioms source code}
}
Jan Heinrich Reimer, Johannes Huck, and Alexander Bondarenko. Grimjack at Touché 2022: Axiomatic Re-ranking and Query Reformulation. In Proceedings of the Working Notes of CLEF 2022 - Conference and Labs of the Evaluation Forum, Bologna, Italy, September 5th - to - 8th, 2022, 2022. CEUR-WS.org. []
@inproceedings{reimer2022grimjack,
  author       = {Jan Heinrich Reimer and
                  Johannes Huck and
                  Alexander Bondarenko},
  title        = {Grimjack at Touch{\'{e}} 2022: Axiomatic Re-ranking and Query Reformulation},
  booktitle    = {Proceedings of the Working Notes of CLEF 2022 - Conference and Labs
                  of the Evaluation Forum, Bologna, Italy, September 5th - to - 8th, 2022},
  series       = {CEUR Workshop Proceedings},
  volume       = {3180},
  publisher    = {CEUR-WS.org},
  year         = {2022},
  url          = {https://downloads.webis.de/publications/papers/reimer_2022a.pdf}
}
Shuming Shi, Ji-Rong Wen, Qing Yu, Ruihua Song, and Wei-Ying Ma. Gravitation-based model for information retrieval. In SIGIR 2005: Proceedings of the 28th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, Salvador, Brazil, August 15-19, 2005, pages 488–495, 2005. ACM. [] [doi]
@inproceedings{shi2005gravitation,
  author       = {Shuming Shi and
                  Ji{-}Rong Wen and
                  Qing Yu and
                  Ruihua Song and
                  Wei{-}Ying Ma},
  title        = {Gravitation-based model for information retrieval},
  booktitle    = {{SIGIR} 2005: Proceedings of the 28th Annual International {ACM} {SIGIR}
                  Conference on Research and Development in Information Retrieval,
                  Salvador, Brazil, August 15-19, 2005},
  pages        = {488--495},
  publisher    = {{ACM}},
  year         = {2005},
  url          = {https://doi.org/10.1145/1076034.1076117},
  doi          = {10.1145/1076034.1076117}
}
Tao Tao and ChengXiang Zhai. An exploration of proximity measures in information retrieval. In SIGIR 2007: Proceedings of the 30th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, Amsterdam, The Netherlands, July 23-27, 2007, pages 295–302, 2007. ACM. [] [doi]
@inproceedings{tao2007exploration,
  author       = {Tao Tao and
                  ChengXiang Zhai},
  title        = {An exploration of proximity measures in information retrieval},
  booktitle    = {{SIGIR} 2007: Proceedings of the 30th Annual International {ACM} {SIGIR}
                  Conference on Research and Development in Information Retrieval,
                  Amsterdam, The Netherlands, July 23-27, 2007},
  pages        = {295--302},
  publisher    = {{ACM}},
  year         = {2007},
  url          = {https://doi.org/10.1145/1277741.1277794},
  doi          = {10.1145/1277741.1277794}
}
Adam D. Troy and Guo-Qiang Zhang. Enhancing relevance scoring with chronological term rank. In SIGIR 2007: Proceedings of the 30th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval, Amsterdam, The Netherlands, July 23-27, 2007, pages 599–606, 2007. ACM. [] [doi]
@inproceedings{troy2007enhancing,
  author       = {Adam D. Troy and
                  Guo{-}Qiang Zhang},
  title        = {Enhancing relevance scoring with chronological term rank},
  booktitle    = {{SIGIR} 2007: Proceedings of the 30th Annual International {ACM} {SIGIR}
                  Conference on Research and Development in Information Retrieval,
                  Amsterdam, The Netherlands, July 23-27, 2007},
  pages        = {599--606},
  publisher    = {{ACM}},
  year         = {2007},
  url          = {https://doi.org/10.1145/1277741.1277844},
  doi          = {10.1145/1277741.1277844}
}
Michael Völske, Alexander Bondarenko, Maik Fröbe, Benno Stein, Jaspreet Singh, Matthias Hagen, and Avishek Anand. Towards Axiomatic Explanations for Neural Ranking Models. In ICTIR '21: The 2021 ACM SIGIR International Conference on the Theory of Information Retrieval, Virtual Event, Canada, July 11, 2021, pages 13–22, 2021. ACM. [] [doi]
@inproceedings{volske2021towards,
  author       = {Michael V{\"{o}}lske and
                  Alexander Bondarenko and
                  Maik Fr{\"{o}}be and
                  Benno Stein and
                  Jaspreet Singh and
                  Matthias Hagen and
                  Avishek Anand},
  title        = {Towards Axiomatic Explanations for Neural Ranking Models},
  booktitle    = {{ICTIR} '21: The 2021 {ACM} {SIGIR} International Conference on the
                  Theory of Information Retrieval, Virtual Event, Canada, July 11, 2021},
  pages        = {13--22},
  publisher    = {{ACM}},
  year         = {2021},
  url          = {https://doi.org/10.1145/3471158.3472256},
  doi          = {10.1145/3471158.3472256}
}
Hao Wu and Hui Fang. Relation Based Term Weighting Regularization. In Advances in Information Retrieval - 34th European Conference on IR Research, ECIR 2012, Barcelona, Spain, April 1-5, 2012. Proceedings, pages 109–120, 2012. Springer. [] [doi]
@inproceedings{wu2012relation,
  author       = {Hao Wu and
                  Hui Fang},
  title        = {Relation Based Term Weighting Regularization},
  booktitle    = {Advances in Information Retrieval - 34th European Conference on {IR}
                  Research, {ECIR} 2012, Barcelona, Spain, April 1-5, 2012. Proceedings},
  series       = {Lecture Notes in Computer Science},
  volume       = {7224},
  pages        = {109--120},
  publisher    = {Springer},
  year         = {2012},
  url          = {https://doi.org/10.1007/978-3-642-28997-2\_10},
  doi          = {10.1007/978-3-642-28997-2\_10}
}
Wei Zheng and Hui Fang. Query Aspect Based Term Weighting Regularization in Information Retrieval. In Advances in Information Retrieval, 32nd European Conference on IR Research, ECIR 2010, Milton Keynes, UK, March 28-31, 2010. Proceedings, pages 344–356, 2010. Springer. [] [doi]
@inproceedings{zheng2010query,
  author       = {Wei Zheng and
                  Hui Fang},
  title        = {Query Aspect Based Term Weighting Regularization in Information Retrieval},
  booktitle    = {Advances in Information Retrieval, 32nd European Conference on {IR}
                  Research, {ECIR} 2010, Milton Keynes, UK, March 28-31, 2010. Proceedings},
  series       = {Lecture Notes in Computer Science},
  volume       = {5993},
  pages        = {344--356},
  publisher    = {Springer},
  year         = {2010},
  url          = {https://doi.org/10.1007/978-3-642-12275-0\_31},
  doi          = {10.1007/978-3-642-12275-0\_31}
}