Written vs. spoken eyewitness accounts: does modality of testing matter?

The aim of the current study was to test whether the modality of testing (written vs. spoken) matters when obtaining eyewitness statements. Writing puts higher demands on working memory than speaking because writing is slower, less practiced, and associated with the activation of graphemic representations for spelling words (Kellogg, 2007). Therefore, we hypothesized that witnesses' spoken reports should elicit more details than written ones. Participants (N = 192) watched a staged crime video and then gave a spoken or written description of the course of action and the perpetrator. As expected, spoken crime and perpetrator descriptions contained more details than written ones, although there was no difference in accuracy. However, the most critical (central) crime and perpetrator information was both more extensive and more accurate when witnesses gave spoken descriptions. In addition to cognitive factors, social factors are considered which may drive the effect.