Qualified soccer coaches (N = 146) rated the ability of two soccer players (a control and target player) each shown, on video, performing a passing task eight times. For the control player, all participants saw the same footage in the same order. For the target player, participants viewed the same footage with half viewing a declining (successful to unsuccessful) performance pattern and half viewing an ascending pattern. Additionally, coaches either received no warning of the danger of order effects, a warning prior to viewing any footage, a warning prior to viewing the target player or a warning prior to rating the target player.
Results indicated that primacy effects were observed in the no warning condition and the warning prior to rating the target. However, when warnings were given prior to observing the target player no order effects were observed.
The results indicate that order effects can be eliminated by warning observers of the phenomenon.