  Referring expression generation (REG) algorithms offer computational models
of the production of referring expressions. In earlier work, a corpus of
referring expressions (REs) in Mandarin was introduced. In the present paper,
we annotate this corpus, evaluate classic REG algorithms on it, and compare the
results with earlier results on the evaluation of REG for English referring
expressions. Next, we offer an in-depth analysis of the corpus, focusing on
issues that arise from the grammar of Mandarin. We discuss shortcomings of
previous REG evaluations that came to light during our investigation and we
highlight some surprising results. Perhaps most strikingly, we found a much
higher proportion of under-specified expressions than previous studies had
suggested, not just in Mandarin but in English as well.
