Before revision:  Models should also consider lexical matches when the query contains rare terms -- such as a person's name or a product model number -- not seen during training, and to avoid retrieving semantically related but irrelevant results.
After revision:  Models should also consider lexical matches when the query contains rare terms--such as a person's name or a product model number -- not seen during training, and to avoid retrieving semantically related but irrelevant results.