This book proposes that one of the most significant parameters contained in the user profile is the age group, appearing that there is typical behavior among the users of the same age group, particularly, when these users compose about the same subject. A detailed analysis with a no. of sentences was performed to decide which characteristics are important, such as, the utilize of punctuation, the number of characters, media sharing, subjects, among others; and which ones can be neglected for the age groups classification. Different learning machine algorithms are tried for the classification of the teenager and adult age group.