PREP vs. Quick Count 

The text of the article suggests (and states overtly at least once) that the PREP and the Quick Count are the same thing. They are most definitely not. 

The Quick Count ("Conteo Rapido", as opposed to the PREP, "Programa the Resultados Electorales Preliminares"), was a statistical sampling model of several polling places. It was meant as a statistical tool of prediction. The results from the Quick Count, which were made public some days later, showed that the statistical tests showed Calderon as winning in all three, but in two of them the difference was within the margin of error and in the third it was only barely outside. It was because of this, as per prior agreement, that the IFE declared the race too close to call (the prior agreement was that the IFE would either state which candidate was projected to be the winner based on the Conteo Rapido, or ask for a couple more hours to collate more results, or declare the race too close to call). The Quick Count was not the PREP. As it happens, the final tally agreed with the Quick Count results.

The PREP on the other hand is the quick dissemination of full results as reported by the district electoral councils to the IFE. There is no statistical component to the PREP, as opposed to the Quick Count which is an entirely statistical analysis of results.

See for example , in which Ugalde speaks of making the results from the Quick Count known, and whether the tecnical committee felt it would be possible to determine the electoral tendencies at the time.  Another note is in:  
Finally, the official report from the tecnical committee is at