Typically—very typically—fledgling African historians launch their careers by engaging in a bout of fieldwork, sometimes in archives, but more often on location among a group of people whose activities have somehow captured their interest. Almost as typically, this work in the field then becomes the principal source for historians' future published work, which often never proceeds beyond the bounds set by the initial fieldwork.
In this process of course the data accumulated in the field—field notes—become, possibly over and over again, the primary sources for this subsequent work. In some ways this process is not particularly different from that undertaken by other historians who use printed sources more heavily. There are differences, though, not the least of which is that these orally derived field notes grow stale with the passing of time and cannot be revivified as easily as archival notes.
Moreover, of course, far more often than not, field notes are never allowed to escape into the public domain, whereas archival sources are usually already there when the historian sets about using them. What were once laboriously handwritten notebooks, and then audio tapes are now more likley to be 3.5″ diskettes, but otherwise they are as jealously guarded in the 1990s as they were in the 1950s. Indeed, perhaps moreso, in that the usable lifespan of a diskette is likely to be significantly less than that of the notebook, if not of the audio tape. In short, in perhaps twenty years posterity will find itself forced to rely on the published products—maybe yet in paper format?—rather than on the raw data which once underpinned them. In the circumstances, it might be worth considering once again the implications of this, with reference to a particular instance of respectable vintage.