To evaluate the forecasts of the participants, details about the actual outcomes were collected from www.fifa.com/worldcup/ archive/germany2006/results/index.html. Forecasting perfor-mance was measured in three ways. Firstly, it concerned the number of the eight selected teams in Task A that actually advanced to the second stage of the World Cup 2006. Accordingly, this measure varied between 0 and 8. Secondly, it referred to the accuracy of the score predictions in Task B that was determined using the following procedure for the responses of each participant.
root mean square error of predicted scores
h X_ _i1=2
¼ 1=ðPM*2Þ ðTGxm_PGxmÞ2þðTGym_PGymÞ2
where PM ¼ total of predicted matches, TG ¼ true number of goals, PG ¼ predicted number of goals, x ¼ team x, m ¼ match number, and y ¼ team y.