Subjective assessment of blunt impacts

An important role of an eyewitness to an assault is to effectively quantify the degree of force used; yet evidence of this form is often subjective and relies on personal opinion. Twelve subjects were asked to strike a load cell with a wooden bat, using varying degrees of force. The strikes were recorded by video camera and 50 people observed the video and were asked to grade the strikes. On average 44% accurately assessed the severity of the strikes, whilst 26% over-estimated. Results suggest that the evidence of eyewitnesses should be treated with caution.