Burrow, J. G. (2016). Is Diurnal Variation a Factor in Bare Footprint Formation? Journal of Forensic Identification, 66(2), 107-117.

This limited study considered whether the collection of the exemplar footprints, and the resultant analysis and comparison, could be influenced by the time of day that the exemplar footprints were collected compared to a possible time when the footprints were first made. Dynamic footprints were collected from individuals on two occasions during the day (four footprints in total for each individual) using a test/re-test design. The Reel method of analysis determined measurements and allowed comparisons between the four sets. A two-way repeated measures ANOVA analysis suggested that diurnal variation was probably not an issue and that exemplar footprints did not show deviations that were due to the time of day when the footprints were collected. This might further suggest that, in this respect, work undertaken on past cases is reliable, and time of day is not a variable that needs consideration and accounting for when working future bare footprint cases. However, caution may be needed where environmental and temperature variables need consideration.