Date of Graduation


Document Type


Degree Name

Bachelor of Arts

Degree Level



Psychological Science


Lampinen, James

Committee Member/Reader

Drawve, Grant

Committee Member/Second Reader

Zabelina, Grant

Committee Member/Third Reader

Bouchillon, Brandon


The current study is a replication and extension of previous research by Colloff and Wixted (2020). In their study, they created a novel identification procedure called the simultaneous showup. They found support for the diagnostic feature detection theory over the filler siphoning theory. The current study was interested in seeing if covert filler siphoning was still occurring in their novel procedure by asking participants how photos of fillers influenced their identification decision. Participants of the study viewed two crime videos and completed an identification task. If they were assigned to the simultaneous showup task, they were asked if and how the fillers influenced their decision. The results of the study showed that support for both filler siphoning and diagnostic feature detection was found. This means that the current study has show that covert filler siphoning occurs even when the option to pick a filler is taken away from the witness.


showup, lineup, filler siphoning, diagnostic feature detection