\begin{enumerate}
	% Question 1a
	\item Disfluencies are annotated by surrounding them with square braces.
		The first bit shows the \emph{reparandum}, the second bit denoted with
		the \texttt{+} shows the \emph{editing phase} and the last bit shows
		the \emph{repair}. We want to only keep the repair since that depicts
		the correct, meant by the speaker, speech.

		\verb#s/\[.*?\+\{.*?\}(.*?)\]/\1/g#

		Bit by bit:
		\begin{itemize}
			\item \verb#s/# Substitution.
			\item \verb#\[# Matches the opening square bracket. We escape this
				because \verb#[# is a regular expression control character and
				we want to match a literal.
			\item \verb#.*?\+# Matches non-greedily everything up to the plus
				mark. Thus the \emph{reparandum}. Note that the
				\emph{reparandum} can be empty (in case the speaker immediately
				start editing). We escape the \verb#+# for the same reason as
				the previous segment.
			\item \verb#\{.*?\}# Matches everything between the curly braces.
				Thus the \emph{editing phase}. Note again that this match can
				only contain empty curly braces since the \emph{editing phase}
				can be empty.
			\item \verb#(.*?)# Matches non-greedily everything up to the
				closing square brace and captures it in the group. Thus the
				\emph{repair}. Note that we do not require this group to be the
				exact same as the \emph{reparandum}.
			\item \verb#\]/# Matches the closing square bracket and we proceed
				to the replacement.  We escape this for  the same reason as
				before.
			\item \verb#\1/g# We replace the entire match with only the
				captured \emph{repair} group and do this globally since there
				can be multiple repairs in an utterance.
		\end{itemize}

	% Question 1b
	\item \textsc{MEMM}'s use features to add extra information to words.
		\textsc{IOB} tagging is a partial parsing or chunking method that only
		discriminates between \emph{Beginning} (\texttt{B}), \emph{Internal}
		(\texttt{I}) and \emph{Outside} (\texttt{O}) categories.

		Say we use the same segmentation as before, we should mark the
		\emph{reparandum} and \emph{editing phase} as \emph{Outside}
		(\texttt{O}) parts and the repair should be parsed as usual.  Note that
		a chunk then can include \texttt{O} marked segments. For example in ``a
		car uh plane'' the ``car uh'' part will be tagged as \texttt{O}, ``a''
		as \texttt{B\_NP} and ``plane'' as \texttt{I\_NP}.

		For the algorithms it might be necessary to add a different tag to
		denote internal \texttt{O} segments. This can be done by adding a
		suffix to the \texttt{O} tag. In the previous example the text will
		then be chunked as: \texttt{B\_NP O\_NP I\_NP}.

		Concerning the \textsc{MEMM} features, obviously editing phase segments
		should be marked as such but also the reparandum should be tagged as
		such to not confuse it with a regular segment.

	% Question 1c
	\item Repairs are only noticed when you can lookahead to the \emph{editing
		phase} markers. It might be necessary to either lookahead a little bit
		or to work outwards from the identified \emph{editing phase}.
		Right-to-left has the same problem as left-to-right in the sense that
		it will see the repair first and also has to lookahead to know whether
		it is part of a repair.
\end{enumerate}
