In recent years there has been a renewed interest in field linguistics and language documentation. One reflection of this trend is the appearance of several relatively new books about doing linguistic fieldwork (e.g. Newman and Ratliff 2001, Vaux and Cooper 1999, Payne 1997). Yet, there remains one area of fieldwork methodology that is rarely dealt with in publications and linguistic field methods courses generally: how and why a linguist should gather information about the life history of the speaker, including, especially, information about the speaker\u27s sociolinguistic background. Such information is critical for linguists investigating moribund languages, where it is not uncommon to find significant differences in the speech of speak...