english: We took 1,300 randomly selected undergraduates, we had them nominate their friends, and we followed both the random students and their friends daily in time to see whether or not they had the flu epidemic.
non_english: Узели смо 1300 насумично одабраних студената, замолили их да наведу своје пријатеље, и пратили смо и насумичне студенте и њихове пријатеље дневно у одређено време, да видимо да ли су заражени или не.