Authors cite other work in many types of documents. Notable among these are research papers and web pages. Recently, several researchers have proposed using the text surrounding citations (references) as a means of automatically indexing documents for search engines, claiming that this technique is superior to index-ing documents based on their content [1,2]. While we ourselves have made this claim, we acknowledge that little empirical data has been presented to support it. Therefore, in the limited space available we present a terse overview of a study comparing refer-ence to content as bases for indexing documents. This study indi-cates that reference identifies the value of documents more accu-rately and with a greater diversity of language than content.