identifying a set of out-of-domain conversations from among a plurality of unassigned conversations using a plurality of existing groups of semantically similar conversations, wherein the set of out-of-domain conversations comprises a first subset of the plurality of unassigned conversations;

determining, based upon the plurality of unassigned conversations, a new candidate group of semantically similar conversations comprising a subset of the plurality of unassigned conversations, the subset of the plurality of unassigned conversations comprising a second subset of the set of out-of-domain conversations, wherein the new candidate group is distinct from the plurality of existing groups of semantically similar conversations, wherein a respective existing group of the plurality of existing groups comprises a distinct subset of conversations assigned to the respective existing group based on a respective representative utterance associated with the respective conversation of the distinct subset of conversations;

determining a clustering performance metric associated with the new candidate group of semantically similar conversations based on a relationship between a reference semantic representation for the new candidate group of semantically similar conversations and respective semantic representations for the plurality of existing groups of semantically similar conversations; and

when the clustering performance metric is greater than a threshold: