Issues of scale are persistent but rarely made explicit in tephrostratigraphy. Eruption magnitude, the nature of available outcrop, and the resolution and type of data available define the scale of any proposed correlation. Different scales require different approaches to demonstrate, or more accurately, to estimate the likelihood of correlation among two or more deposits. This is emphasized through a probabilistic approach to the correlation of proximal and distal tephra deposits associated with Lower and Middle Paleolithic archaeological sites from central Turkey through the use of discriminant analyses and multiple analyses of variance. (C) 2011 Elsevier Ltd and INQUA. All rights reserved.