Attempts to use natural language processing (NLP) for text categorization and information retrieval (IR) have had mixed results. Nevertheless, there is a strong intuition that NLP is important, at least for some tasks. In this paper, we discuss a task involving captioned images for which the subject and the predicate are critical. The usefulness of NLP for this task is established in two ways. In addition to the standard method of introducing a new system and comparing its performance with others in the literature, we also present evidence from experiments with human subjects showing that NLP generally improves speed and accuracy.