\section{Background: ARRAU 1 and 2}
% \section{Targeting the more complex forms of anaphoric reference: ARRAU 1 and 2}
\label{sec:ARRAU2}

Most modern anaphoric annotation projects cover those aspects of anaphoric reference  for which reliable annotation schemes have been found
\cite{poesio&vieira:CL,poesio:ACL-discanno04,artstein&poesio:CL}
--in particular, basic identity anaphora between entities introduced via nominal phrases in written text, as in \SREF{ex:identity}.
\begin{exe}
\ENEW{ex:identity} [Mary]$_i$ bought [a new dress]$_j$ 
      but [it]$_j$ didn't fit [her]$_i$.
\end{exe}
%\LINGEX{[Mary]$_i$ bought [a new dress]$_j$, but [it]$_j$ didn't fit [her]$_i$.} in written text.
In this Section, we discuss the additional aspects of anaphoric reference the {\ARRAU} annotation project was meant to cover and introduce the first two releases of the corpus \footnote{\url{http://www.arrauproject.org/corpus}} \cite{poesio&artstein:LREC08,uryupina-et-al:NLEJ}.
% But the objective of the {\ARRAU} annotation project was to broaden the range of anaphoric phenomena and genres covered. 
% %
% In this Section, we discuss the previous release of the {\ARRAU} corpus\footnote{\url{http://www.arrauproject.org/corpus}} \cite{poesio&artstein:LREC08,uryupina-et-al:NLEJ}, the genres it was meant to cover, and the aspects of anaphoric reference to be included.

% Plan for this Section:

% \begin{itemize}
%     \item Quick description of {\ARRAU} 2 with discussion of some key aspects of the annotation scheme and some statistics
% \end{itemize}

% \paragraph{Genres}  The first release  of the {\ARRAU} corpus \cite{poesio&artstein:LREC08} focused on dialogue. 
% In particular, its
% {\TRAINS} domain of task-oriented dialogues includes
% a complete annotation of the {\TRAINS-93}  
% corpus\footnote{\url{http://www.ldc.upenn.edu/Catalog/catalogEntry.jsp?catalogId=LDC95S25}} 
% and the pilot dialogues in the so-called {\TRAINS-91} corpus.

% The second release of the {\ARRAU} corpus\footnote{\url{http://www.arrauproject.org}} \cite{uryupina-et-al:NLEJ}
% was designed to cover a broader variety of genres than the first.
% Version 2 includes a substantial amount of news 
% text in a  
% sub-corpus called \CODE{RST}, consisting of the  Penn Treebank \cite{marcus-et-al:CL93}.
% In addition,  {\ARRAU} Version 2 includes a complete annotation of the spoken narratives in the Pear Stories 
% \cite{chafe:80},
% and  documents in the medical and art history genres from the {\GNOME} corpus \cite{poesio:ACL-discanno04}.

\subsection{Genres} 

The {\ARRAU} corpus was designed to cover a broad variety of genres, and in particular  
%Initially, the corpus was created to cover anaphoric reference in 
dialogue and spoken language \cite{poesio&artstein:LREC08}.
Its \CODE{TRAINS} sub-corpus includes all the task-oriented dialogues in the {\TRAINS-93}  
corpus\footnote{\url{http://www.ldc.upenn.edu/Catalog/catalogEntry.jsp?catalogId=LDC95S25}} \cite{heeman&allen:trains-corpus-93}
already used in Byron's work on  pronominal reference in dialogue \cite{byron&allen:98,byron:ACL02}
as well as the pilot dialogues in the so-called {\TRAINS-91} corpus. 
The \CODE{PEAR} sub-corpus consists of 
the complete collection of spoken narratives in the Pear Stories that provided some of the early evidence on salience and anaphoric reference   
\CITE{chafe:80}.\footnote{\url{https://www.linguistics.ucsb.edu/research/pear-film}}
Subsequently, the corpus was extended to 
cover %a substantial amount of 
news text in a  
sub-corpus called \CODE{RST}, consisting of the entire subset of the Penn Treebank \CITE{marcus-et-al:CL93}
that was annotated in  the \ACRO{rst} treebank
\CITE{carlson(lynn)-et-al:03}.\footnote{\url{https://catalog.ldc.upenn.edu/LDC2002T07}}
The \CODE{GNOME} sub-corpus covers documents from the medical and art history genres from the {\GNOME} corpus \CITE{poesio:ACL-discanno04}.


\subsection{Pushing the boundaries %of anaphoric reference
} 

The annotation scheme for {\ARRAU} 1 and 2 was  designed to extend both the range of markables and the range of relations annotated in previous efforts, taking advantage of the possibilities offered by the {\MMAX}2  annotation tool \CITE{mueller&strube:06}. 

% Most modern anaphoric annotation projects cover those aspects of anaphoric reference for which good reliability has been shown \cite{poesio&vieira:CL,poesio:ACL-discanno04,artstein&poesio:CL}
% --in particular, basic identity anaphora between entities introduced via nominal phrases, as in \LINGEX{[Mary]$_i$ bought [a new dress]$_j$, but [it]$_j$ didn't fit [her]$_i$.}
% But the objective of the {\ARRAU} annotation project was to broaden the range of anaphoric phenomena and genres covered. 

%\SREF{ex:identity}.
% \begin{exe}
% \ENEW{ex:identity} [Mary]$_i$ bought [a new dress]$_j$ 
%       but [it]$_j$ didn't fit [her]$_i$.
% \end{exe}

% The same coding scheme was used for all sub-corpora, 
% but separate guidelines were written for the textual  and the
% spoken dialogue sub-corpora.
% The original annotation scheme used for Release 1 \cite{poesio&artstein:LREC08}, focused on dialogue, is distributed with the dataset and is also available  from the {\ARRAU} corpus page.
% %
% For the second release \cite{uryupina-et-al:NLEJ}, the guidelines for bridging were extended and genericity was also annotated using the {\GNOME} guidelines, but a complete new manual was not produced. However, a fairly extensive description can be found in \CITEA{uryupina-et-al:NLEJ}. 


\paragraph{Markable definition}
% To shorten
% Many
% older %, especially among the older, 
% anaphorically annotated  corpora impose syntactic, semantic or discourse-based restrictions on
% markables.
% For instance, in old information-extraction oriented corpora such as \ACRO{ace} only entities of certain type are treated as markables, 
% whereas in {\ONTONOTES}  non-referring nominals  (e.g., expletives such as \LINGEX{it}  in \LINGEX{[It] is four o'clock}) are excluded. 
% % For instance, in {\ONTONOTES} neither non-referring nominals  (e.g., expletives such as \LINGEX{it}  in 
% % \LINGEX{[It] is four o'clock}
% % or  predicative {\NP}s such as 
% % \LINGEX{a busy place} in \LINGEX{This seems to be [a busy place]}) nor singletons (references to entities only mentioned once) 
% % are annotated.
% (For a discussion of different markable choices in  anaphoric
% annotation, see \CITEA{poesio-et-al:ana-book-corpora}.)
% By contrast,
In {\ARRAU}, 
in contrast with earlier corpora,
\textit{all} {\NP}s are  markables, including 
%when they are
non-referring expressions and singletons. 
All markables are then sub-classified according to their semantic interpretation (i.e., whether they are referring or not, and if not, what type of semantic interpretation they have--e.g., %quantifier, 
expletive, predicate) as discussed below. 
%
In addition, 
premodifiers are considered markables when the  entity referred to
is mentioned again, as 
with %in the case of the 
proper name \LINGEX{US} in
\SREF{ex:ARRAU-premodifiers:a}.
% Cut to shorten
% or of premodifiers that refer to a  kind, like
% \LINGEX{exchange-rate} in \SREF{ex:ARRAU-premodifiers:b}. 

\begin{exe}
% \ENEW{ex:non-referring} 
%       [It] seems to be [a busy place]
\ENEW{ex:ARRAU-premodifiers:a}
\ldots The Treasury Department said that the [US]_1 trade deficit may worsen next year after two years of significant improvement\ldots
The statement was the [US]_1's government first acknowledgment \ldots
% Cut to shorten
% of
% what other groups, such as the International Monetary Fund, have 
% been predicting for months. 

% \ENEW{ex:ARRAU-premodifiers:b}
% The Treasury report, which is required annually by a provision
% of the 1988 trade act, again took South Korea to task for its
% [exchange-rate]_1 policies. ``We believe there have continued to be
% indications of [exchange-rate]_1 manipulation \ldots
\end{exe}
A distinctive feature of {\ARRAU}'s definition of markables 
are %is the existence of  
\NEWTERM{discontinuous} markables such as the collaborative constructed \LINGEX{three ... loaded boxcars} in \SREF{ex:discontinuous}, building on M{\"{u}}ller's work \cite{mueller:thesis} and leveraging {\MMAX}2's support for such markables.

\begin{exe}
    \ENEW{ex:discontinuous}
    \begin{tabular}{cl}
      S:  &  okay um if you can only pull three  \\
         &  loaded boxcars\\
      U:  & {[three]$^1$}\\
      S:  & yeah [loaded boxcars]$^1$
    \end{tabular}
\end{exe}

\paragraph{The semantic function of noun phrases}

The nominal expressions
%anaphoric expressions 
in \SREF{ex:identity} and %\SREF{ex:split} 
are examples of 
\NEWTERM{referring} noun phrases, which either introduce new entities in a discourse (first mention of Mary and the new dress)  or link to previously introduced entities (pronouns \LINGEX{it} and \LINGEX{her}).
% The items annotated in anaphoric corpora tend to be a subset of referring {\NP}s.
But other types of {\NP}s exist. 
\NEWTERM{Quantificational} {\NP}s 
  %\index{noun phrase!quantifier}  
  such as %the  noun phrase 
  \LINGEX{No one} 
  in \LINGEX{No one would put the blame on him/herself} \CITE{partee:72} 
  do not refer to an individual or set of individuals,
  but can still participate in anaphoric relations 
   even though 
   anaphoric reference to quantifiers 
   has distinctive properties 
   %has different properties from anaphoric reference to referring noun phrases 
  \CITE{partee:72} 
   and is subject to semantic constraints %discussed e.g., in 
  \CITE{karttunen:76}.
%   such as 
%   the fact that pronoun \LINGEX{it} in \SREF{ex:karttunen} cannot corefer with the car \CITE{karttunen:76} 
%
% \begin{exe}
% \ex \label{ex:karttunen}
%     [John]$_i$ has [no car]$_j$. *[It]$_j$ is black.
% \end{exe}
\NEWTERM{Predicative} noun phrases 
 %\index{noun phrase!predicative} 
  express properties of
  objects: 
  for instance, in 
  \LINGEX{This seems to be [a busy place]}) , 
  %sentence \SREF{ex:non-referring},
  %the clause \LINGEX{John is a good man} 
  %in %example \SREF{ex:anaphora}, 
  the {\NP} %noun phrase 
  \LINGEX{a good place}
  %\LINGEX{a good man} 
  does not introduce a new discourse entity or refer back to an existing discourse entity, 
  but expresses a property. % of John. 
Finally, 
 %\index{noun phrase!expletives} 
In languages like English, 
% CUT TO SHORTEN
% where verbal arguments always have  be explicitly realized, 
forms like \LINGEX{it} and 
\LINGEX{there} can also be used to
express semantically vacuous \NEWTERM{expletives} as well as pronouns,
like the \LINGEX{it} in 
\LINGEX{It is four o'clock}.
%\SREF{ex:non-referring}.
%\LINGEX{It is half past two}. 
Distinguishing referring from non-referring nominals is a part of the task of  interpreting anaphoric expressions
which cannot  be evaluated 
in corpora where non-referring expressions are not annotated.
%
% \begin{exe}
% \ENEW{ex:non-referring} 
%       [This] seems to be [a busy place]
% \end{exe}
In {\ARRAU},
%The {\ARRAU} guidelines require annotating 
a markable's  semantic type 
is annotated
%referential status  
using the \CODE{reference} attribute. 
A markable can be marked as being semantically  non-referring-- an expletive, a predicate, a quantifier, a coordination, an idiom, or incomplete--or referring--either \CODE{discourse new} or
\CODE{discourse old} (see next). 

% Redundant?
% \paragraph{Types of anaphoric reference}

% % The {\ARRAU} guidelines require annotating a markable's referential status  using the \CODE{reference} attribute. 
% % A markable can be marked as being semantically  non-referring-- an expletive, a predicate, a quantifier, a coordination, an idiom, or incomplete--or referring--either \CODE{discourse new} or
% % \CODE{discourse old}. 
% Discourse new mentions introduce new entities and thus are not marked as being coreferent with an entity already introduced  (\NEWTERM{antecedent}).
% For discourse-old markables, the annotation of different types  of anaphoric relations is supported.
% % All referring markables are marked as either \CODE{discourse new} or
% % \CODE{discourse old}. 
% The  antecedent of discourse-old mentions can be either of type
% \CODE{phrase} (if the antecedent was introduced using a nominal markable) or  
% \CODE{segment} (not introduced by a nominal markable,
% for \NEWTERM{discourse deixis}).
% Identity anaphora also includes split antecedent plural anaphoric reference, discussed next.   
% In addition, referring {\NP}s can be marked as \NEWTERM{related} to a
% previously mentioned discourse entity %in order
% to identify them as
% examples of  associative (\NEWTERM{bridging}) anaphora.

\paragraph{Split-antecedent anaphora} 
The antecedent in cases of identity reference is not necessarily an entity introduced via a nominal. 
A classic illustration of this is 
\NEWTERM{split-antecedent anaphora} 
\CITE{eschenbach1989remarks,kamp&reyle:93}, exemplified by \SREF{ex:split},  where a plural pronoun (\LINGEX{they}) refers to a set  composed of two  entities introduced by separate  noun phrases.
% Although fairly rare, it 
% demonstrates that %highlights how not 
% %is important as an illustration of the fact that 
% not  all types of identity reference refer to an entity introduced via a nominal. 
% Such references are  annotated in, e.g., {\ARRAU} \CITE{uryupina-et-al:NLEJ}, {\GUM} \CITE{Zeldes2017} and  {\PD}  \CITE{poesio-et-al:NAACL19}.

% \vspace{-5pt}
\begin{exe}
\ENEW{ex:split}
    [John]$_1$ met [Mary]$_2$. [He]$_1$ greeted [her]$_2$. [They]$_{1,2}$ went to the movies.
\end{exe}
% Such references are not annotated in many corpora.
% In other corpora, \LINGEX{They} would be treated as a bridging reference.

\paragraph{Non-identity anaphora}
Anaphoric expressions do not necessarily refer to their antecedent entity. 
Possibly the most studied type of non-identity anaphora is \NEWTERM{bridging reference} or \NEWTERM{associative anaphora}  \CITE{clark:bridging,hawkins:78,prince:81} as in 
\LINGEX{she found herself in [a long, low hall, which was lit up by a row of lamps hanging from \underline{[the roof]}},
%\SREF{ex:bridging}, 
where
% Cut to save space
% bridging reference / associative anaphora 
\LINGEX{the roof} refers to an object which is related to,
%/ associated with, 
but not identical to, the \LINGEX{hall}.
%
% \begin{exe}
% \ENEW{ex:bridging} 
% %There was not a moment to be lost: away went Alice like the wind, and was just in time to hear it say, as it turned a corner, 'Oh my ears and whiskers, how late it's getting!' 
% She was close behind it when she turned the corner, but the Rabbit was no longer to be seen: she found herself in [a long, low hall, which was lit up by a row of lamps hanging from \underline{[the roof]}].
% \end{exe}

Annotating --- indeed, even identifying --- bridging references in a reliable
way is difficult, which is one
of the reasons why so few large-scale corpora for anaphora include
this type of annotation \CITE{poesio-et-al:ana-book-corpora,kobayashi-ng-2020-bridging}. 
The {\ARRAU} guidelines for bridging anaphora are based on 
experiments that were started by Vieira and Poesio \CITE{poesio&vieira:CL} 
and continued in the {\GNOME} project \CITE{poesio:ACL-discanno04}.
The {\ARRAU} Release 1 and 2 guidelines followed the {\GNOME} guidelines,
but with an extension and a simplification.  
Annotators were asked to mark a markable as \CODE{related} to a particular antecedent if it stood to that antecedent in one of the relations identified in 
{\GNOME} (indeed, the same examples were used).
% Cut to save space
%
% and in addition, if they stood in two additional relations %(but
% %without testing the reliability of this annotation): 
% \begin{itemize}
% \item \CODE{other}, for \LINGEX{other} {\NP}s, broadly following the
%   guidelines in \CITEA{modjeska:thesis}; 
% \item an \CODE{undersp-rel} relation for `obvious cases of bridging
%   that didn't fit any other category'.  
% \end{itemize}
% % Some statistics about bridging references in {\ARRAU} Release 2 are
% % shown in Table \ref{t:bridging}. 
However, the actual relations were not marked in {\ARRAU} 1. Relation annotation started with {\ARRAU} 2, but only for the {\RST} portion. 
One of the objectives of  {\ARRAU} 3  was to annotate the relations  underlying bridging reference for all sub-corpora.

Other types of non-identity anaphora also exist, 
besides
% which cannot %however 
% be  considered
bridging references.
%because their status is lexically specified.  
Examples include \LINGEX{other} anaphora like \LINGEX{the other} in
\LINGEX{ohn gave one book to Mary,  and [the other] to Bill}%\SREF{ex:other}, 
as well as \NEWTERM{identity of sense} anaphora such as  \LINGEX{a blue one} in 
\LINGEX{John bought a red ball, and Mary  [a blue one]}
%\SREF{ex:sense} 
\CITE{poesio:ana-book-linguistic}.
\LINGEX{other} anaphora was marked in {\ARRAU} 2, but identity of sense anaphora wasn't.
%These types of non-identity anaphora were not annotated in {\ARRAU} 1 and 2.

% Cut to save space
% \begin{exe}
% \ENEW{ex:other}   John gave one book to Mary,  and [the other] to Bill.
% \ENEW{ex:sense}   John bought a red ball, and Mary  [a blue one].
% \end{exe}

\paragraph{Discourse deixis}
%The term `anaphoric reference' covers a wide variety of phenomena, not all of which are annotated in all corpora. 
\NEWTERM{Event anaphora} is the type of anaphoric reference
exemplified by \LINGEX{that} in \SREF{ex:dd}, which does not refer to an entity introduced using a nominal, but to the event of a white rabbit with pink ears running past Alice

\begin{exe}
% \ENEW{ex:event-anaphora} So she was considering in her own mind (as well as she could, for the hot day made her feel very sleepy and stupid), whether the pleasure of making a daisy-chain would be worth the trouble of getting up and picking the daisies, when suddenly a White Rabbit with pink eyes ran close by her.
% There was nothing so VERY remarkable in \underline{[that]}; nor did Alice think it so VERY much out of the way to hear the Rabbit say to itself, 'Oh dear! Oh dear! I shall be late!' (when she thought it over afterwards, it occurred to her that she ought to have wondered at this, but at the time it all seemed quite natural); ...

\ENEW{ex:dd} ...
when suddenly a White Rabbit with pink eyes ran close by her. 
There was nothing so VERY remarkable in \underline{[that]}; 
% Cut to save space
%nor did Alice think it so VERY much out of the way to hear the Rabbit say to itself, 'Oh dear! Oh dear! I shall be late!' (when she thought it over afterwards, it occurred to her that she ought to have wondered at \underline{[this]}, but at the time it all seemed quite natural); 
....
% but when the Rabbit actually TOOK A WATCH OUT OF ITS WAISTCOAT-POCKET, and looked at it, and then hurried on, Alice started to her feet, for it flashed across her mind that she had never before seen a rabbit with either a waistcoat-pocket, or a watch to take out of it, and burning with curiosity, she ran across the field after it, and fortunately was just in time to see it pop down a large rabbit-hole under the hedge.

\end{exe} 
% \vspace{-5pt}
Event anaphora is 
the simpler example of the type of reference known as \NEWTERM{discourse deixis} \CITE{webber:91,kolhatkar-et-al:CL18} which also includes more complex references 
to, e.g., 
% cut to save space
%like    \LINGEX{this} in \SREF{ex:dd}, which does not refer to an event, but to 
the fact that the Rabbit was able to talk. 
% A more extensive annotation of event anaphora is found in corpora such as the multi-sentence \ACRO{amr} corpus \cite{ogorman-et-al:COLING18}
% and more complex discourse deictic references are
% %A wider range of discourse deixis is  
% marked in, e.g.,  {\ANCORA} and {\ARRAU}.
%Not many corpora attempt to cover the entire range of discourse deixis.

Discourse deixis in its full form 
is a very complex form of reference,
both to annotate 
and to resolve \cite{kolhatkar-et-al:CL18}, 
so very few anaphoric annotation projects have attempted to annotate
discourse deixis in its entirety.
% Cut to save space
%\CITE{kolhatkar-et-al:CL18}.
More typical is a partial annotation, as in
\CITE{byron&allen:98,navarretta:00,pradhan-et-al:ICSC07,kolhatkar&hirst:EMNLP14}.
% Cut to save space
% \CITE{byron&allen:98,navarretta:00}, 
% %\todo{citation not added to bib file}
% who annotated pronominal reference to abstract objects; 
% in \ACRO{OntoNotes}, where event anaphora was marked
% \CITE{pradhan-et-al:ICSC07}; 
% and in the work of \CITEA{kolhatkar&hirst:EMNLP14}, which focused on
% so-called shell nouns.
In {\ARRAU},
a coder  specifying that a referring expression is discourse-old
  is asked  whether its antecedent was introduced using a
  \CODE{phrase} (markable)  or a \CODE{segment} (discourse segment).   
Coders who choose \CODE{segment} %as the type of antecedent
  have to
  mark a sequence of \textit{predefined} clauses as antecedent.
\paragraph{Genericity}
  % \paragraph{The interplay between anaphora and other semantic properties of nominals: genericity}

Often, whether two mentions corefer depends on how they get semantically interpreted in other respects. 
In \SREF{ex:generic-anaphora}, for instance, whether the mention \LINGEX{bananas} in 40.2 is interpreted as coreferring with mention \LINGEX{bananas} in 37.8 depends on whether these bare plurals are taken to be references to the generic kind \textbf{bananas} \cite{carlson&pelletier:95}.
If those mentions are interpreted as 
non-generic, %referring existentially, 
they would not corefer. 
Some anaphoric corpora therefore include an annotation of noun phrases' genericity \cite{uryupina-et-al:NLEJ,nedoluzhko:LAW13}.

\begin{exe}
\ENEW{ex:generic-anaphora} 
{\small 
\begin{tabular}{lrl}
37.1	& M: & all right\\
%37.2	&  : & and then at the same time\\
        &   & ... \\
% 37.3	 : uh what the _heck_ were we doing
% 37.4	 : uh engine ... [tapping]
37.5	& : & E2 was zipping over to Bath \\
        &   & to pick up a boxcar\\
37.6	& : & heading down to Avon\\
37.7	& : & to \\
37.8	& : & collect [bananas]$_i$\\
37.9	& : & and then shipping [em]$_i$ back to \\
        &   & Corning\\
%37.10	& : & shortest route \\
        &   & ... \\
% 37.11	 : well
% 37.12	 : it's probably got a _conflict_ with the other guy going
% 	   through Dansville so it's gonna have to go back through Bath 
38.1	& S: & okay so \\
38.2	&: & E2 \\
38.3	& : & goes to Corning\\
38.4	& : & then \\
38.5	& : & on to Bath \\
38.6	& : & and gets a boxcar \\
39.1	& M: & m hm \\
40.1	&S: & then on to Avon \\
40.2	& : & load [bananas]$_{?}$
\end{tabular}}
\end{exe}

%\paragraph{Genericity}

% Cut to save space
% {\ARRAU} is not a multi-layer corpus like other  corpora such as {\ANCORA}, {\GUM}, {\ONTONOTES} or the Prague Dependency Treebank, meaning that in addition to information about anaphora, other linguistic information relevant for the study of anaphora (morphosyntax, dependency structure, semantics) also has to be annotated within the anaphoric layer.
% In this paper we focus on the annotation of 
% genericity, %the \CODE{generic} attribute, 
% as it's the one among these attributes for which the guidelines changed in {\ARRAU} 3.

The {\ARRAU} scheme and guidelines for genericity build on the studies of genericity reliability carried out as part of the {\GNOME} annotation \cite{poesio-et-al:ACL04}.
This scheme is based on a generalised notion of scopal dependence for nominals covering both genericity and scopal dependence on a range of operators including conditionals, quantifiers, and temporal adverbials. 
In {\ARRAU} 2, 
coders are first asked to check whether the nominal  is  in the \emph{syntactic} scope of an \emph{explicit} operator such as 
a conditional (as in \LINGEX{the gap could grow if there is [a recession]}, a modal, or a quantifier. 
If  such explicit quantifier/modal/conditional is present, the nominal is \textit{not} marked as generic, but as being in the scope of the appropriate operator. 
Otherwise, coders check the nominal refers to  semantic objects whose genericity we leave underspecified, such as substances, as in \LINGEX{not that [oil] suddenly is a sure thing again}. 
Finally, the annotator is asked whether the  markable refers generically  (as in \LINGEX{In its report to Congress on [international economic policies], the Treasury said that ...}).
If so, the nominal is marked as  \CODE{generic-yes},or \CODE{generic-no} otherwise.

% Compressed to save space
% More specifically, 
% according to the guidelines used for 
%  {\ARRAU} 1 and 2,
% the annotation of the \CODE{generic} attribute is carried out following a decision tree going from the easiest cases to the more complex ones.
% Coders are first asked to check whether the nominal  is  in the syntactic scope of an \emph{explicit} operator such as 
% a conditional  like \LINGEX{if} (as in \SREF{ex:genericity:op-conditional}).
% or an  individual quantifier such as \LINGEX{every} or \LINGEX{most} (\CODE{iquant}) 
% %(as in \SREF{ex:genericity:iquant}).
% % or a temporal quantifier like \LINGEX{always} or \LINGEX{once} (as in \SREF{ex:genericity:tquant})
% % a modal (as in \SREF{ex:genericity:modal}) 
% %or an instruction (as in \SREF{ex:genericity:instruction}). 
% In these cases, the nominal is \textit{not} marked as generic, but as being in the scope of the appropriate operator. 
% If no such explicit quantifier/operator is present, coders are asked to check 
% whether the nominal refers to  semantic objects whose genericity is  left underspecified, such as substances (e.g., \textit{gold}), as in 
% \SREF{ex:genericity:underspecified-substance:RST} 
% % seen before or in 
% % \SREF{ex:genericity:underspecified-substance:GNOME}.
% Finally, the annotator is asked whether the sentence in which the markable occurs is generic, 
% and in this case, 
% to mark the nominal as  \CODE{generic-yes} if it refers generically, as in \SREF{ex:genericity:generic-yes},
% or \CODE{generic-no} otherwise.
% With these instructions, reasonable intercoder agreement was  achieved 
% ($\kappa = .82$) \cite{poesio:ACL-discanno04}.

% \begin{exe}
% \ENEW{ex:genericity:op-conditional}
% New York State Comptroller Edward Regan predicts a \$ 1.3 billion budget gap for the city `s next fiscal year, a gap that could grow if there is $[$a recession$]^{operator-conditional}$.`` %\\ 
% %(\CODE{operator-conditional})
% % \item  \label{ex:genericity:op-conditional}
% % S: okay so that was so we'll get to Dansville about four AM now the other problem is is that if we have $[$this train$]$ so we also have engine E one that's going back and forth right $[$operator-conditional$]$
% %\ENEW{ex:genericity:iquant}
% %Mr. Uhr said that Mr. Petrie or his company have been accumulating Deb Shops stock for several years, each time issuing $[$a similar regulatory statement$]^{operator-iquant}$. %\\
% %(\CODE{operator-iquant})
% % \ENEW{ex:genericity:tquant}
% % In addition , once $[$money$]^{generic}$ is raised , $[$investors$]^{generic}$ usually have no way of knowing how $[$it$]^{generic}$ is spent.\\ 
% % (\CODE{operator-tquant})
% % %NB: coreference for generic here
% % \ENEW{ex:genericity:modal}
% % They argue that their own languages should have $[$equal weight$]^{generic}$, although recent surveys indicate that the majority of the country`s population understands Filipino more than any other language.\\
% % (\CODE{operator-modal})
% % \ENEW{ex:genericity:instruction}
% % Use $[$alcohol wipes$]^{generic}$ to clean the tops of the vials move in one direction and use one wipe per vial.\\ 
% % (\CODE{operator-instruction})
% \ENEW{ex:genericity:underspecified-substance:RST}
% Not that $[$oil$]^{undersp-substance}$ suddenly is a sure thing again .%\\
% %(\CODE{undersp-substance}, \CODE{RST})
% % \ENEW{ex:genericity:underspecified-substance:GNOME}
% % 1 ml of $[$the prepared solution for injection$]^{generic}$ contains 0.25 mg ( 8 million IU ) of $[$Interferon beta-1b$]^{generic}$.\\
% % \CODE{underspecified-substance}, \CODE{GNOME})
% \ENEW{ex:genericity:generic-yes}
% In its report to Congress on $[$international economic policies$]^{generic-yes}$, the Treasury said that any improvement in the broadest measures of trade, known as the  current account.%\\
% %(\CODE{generic-yes})
% %-- is the firs one (the prepared solution for injection) really generic? $]$}
% %\item  \ToDo{$[$generic-no$]$}
% % \item  okay $[$it$]$ takes an hour to load each boxcar
% %  \ToDo{$[$episodic-no. how is it different from expletive?$]$}
% %\item  \ToDo{$[$no-generic$]$}
% %\item  \ToDo{$[$operator-question$]$}
% %\item  \ToDo{$[$underspecified-decease$]$}
% %\item  \ToDo{$[$underspecified-generic$]$}
% %\item $[$one of them$]$ has a what do you call those little um paddleball
% %\ToDo{$[$underspecified-replicable$]$}
% \end{exe}

% The version used in {\ARRAU} 1 and 2 ... 

\todo{Mention here the issues with dialogue annotation, in particular not marking first and second person pronouns in {\TRAINS}?}

\todo{Mention here the marking of ambiguity?}

\paragraph{Anaphoric reference in dialogue}

%Arguably the most important among these is conversational language in dialogue.
Anaphora resolution in dialogue requires systems to handle 
grammatically incorrect language suffering from disfluencies and
mentions jointly created across utterances \cite{poesio&rieser:completions} or whose function is to establish common ground rather than refer \cite{clark&brennan:90,heeman&hirst:95}.
Dialogue involves much more deictic reference, vaguer anaphoric and discourse deictic reference,  speaker grounding of pronouns and long-distance conversation structure than in the genres that constitute the bulk of current anaphoric datasets.
% These are complexities that are 
% normally absent from %often missing in 
% news or Wikipedia articles, which 
% constitute the bulk of %form a large chunk of 
% current datasets for coreference resolution \cite{poesio-et-al:ana-book-corpora}.
So although some datasets for anaphoric reference in dialogue in English exist \cite{byron:ACL02,eckert&strube:01,mueller:thesis},
much more is needed, although the situation is better for other languages \cite{muzerelle-et-al:LREC14,grobol:2020:thesis}.
% There has been some research on coreference in dialogue in English \cite{byron:ACL02,eckert&strube:01,mueller:thesis}, but very limited in scope (primarily related to pronominal interpretation), due to the lack of suitable corpora, although the situation is better for other languages \cite{muzerelle-et-al:LREC14,grobol:2020:thesis}.
This is why {\ARRAU} was originally designed to cover anaphoric reference in dialogue.
But in fact, very few specific guidelines were provided for these dialogue-specific aspects of anaphoric reference, focusing instead on discourse deixis and ambiguity.
For instance, first and second person pronouns were not annotated in the \CODE{trains} subcorpus in {\ARRAU} 1 and 2, as it was thought their interpretation could easily be obtained from information about the participants.

% Cut to save space
% \subsection{Annotation}

% {\ARRAU} 1 and 2 were annotated  using  {\MMAX}2  \CITE{mueller&strube:06}. 

% Cut to save space
% \subsection{Coding manual and annotation procedure}

% \paragraph{Coding scheme}
% The same coding scheme was used for all sub-corpora, 
% but separate guidelines were written for the textual  and the
% spoken dialogue sub-corpora.
% The original annotation scheme used for Release 1 \cite{poesio&artstein:LREC08}, focused on dialogue, is distributed with the dataset and is also available  from the {\ARRAU} corpus page.
% %
% For the second release \cite{uryupina-et-al:NLEJ}, the guidelines for bridging were extended and genericity was also annotated using the {\GNOME} guidelines, but a complete new manual was not produced. However, a fairly extensive description can be found in \CITEA{uryupina-et-al:NLEJ}. 

% \paragraph{Annotation procedure}

% {\ARRAU} 1 and 2 were annotated  using  {\MMAX}2  \CITE{mueller&strube:06}. 

% {\ARRAU} 1 was primarily annotated at the University of Essex between 2004 and 2007 by Laura Bostock, Rhiannon Jones and Tara Sutton, under the direction of Ron Artstein, who also designed the {\MMAX} 2 style, and in  collaboration with Mark-Christoph M\"{u}ller. 
% The initial annotation was then extended and checked as part of the Johns Hopkins 2007 Workshop on Entity Disambiguation (\ACRO{elerfed}) by Ron Artstein, Janet Hitzeman, Mijail Kabadjov,  Massimo Poesio, and Josef Steinberger. 
% The annotation started with part of the {\TRAINS} 1991 and 1993 datasets, and was then extended to include a subset of the {\GNOME} corpus, the Pear Stories, and part of the {\RST} Discourse Treeebank already partially annotated by Andrej Kibrik's team at the Russian Academy of Sciences. 

% {\ARRAU} 2 was primarily annotated at the University of Trento between 2008 and 2016 under the coordination first of Kepa Rodriguez, then Francesca Delogu,  Federica Cavicchio, and Olga Uryupina. Most of the annotation was carried out by Antonella Bristot. 

\subsection{Use in shared tasks}

In recent years, {\ARRAU} was used for three shared tasks: the {\CRAC} 2018 shared task on anaphora resolution with the {\ARRAU} corpus \cite{poesio-etal-2018-anaphora}, and the 2021 and 2022 {\CODICRAC}
shared tasks on anaphora resolution in dialogue \cite{khosla-et-al:CODICRAC21,yu-et-al:CODI-CRAC-22}.

The use of the corpus for such tasks was enabled by two improvements brought about by the Universal Anaphora initiative.\footnote{http://www.universalanaphora.org}
The first of these was the development of a tabular markup format extending the {\CONLL}-U tabular format used for the {\CONLL} 2011 and 2012 shared tasks on coreference \cite{pradhan2012conllst} with ways to represent the additional types of anaphoric information encoded in {\ARRAU}, but consistent with it so that modellers would understand it better. 
And second, the development of scorers extending the Coreference Reference scorer \cite{pradhan-etal-2014-scoring} with ways of scoring the interpretation of these additional phenomena \cite{poesio-etal-2018-anaphora,yu-et-al:UA-scorer-22}.

%The important point of these shared tasks for the present paper is that they revealed a number of issues with {\ARRAU} 2, which wee aimed to address in the present release.

%  \CODE{RST}, \CODE{TRAINS}-93 and \CODE{PEAR} were used for the {\CRAC} 2018 shared task.