Separate and Unequal 15-Year-Olds Share Close Share Why is Facebook not here? Why is Twitter not here? Share on LinkedIn Share on Google Plus Permalink Email David C. Berliner December 4, 2001 Author: David C. Berliner Institution: Arizona State University An op-ed piece on 2001 results of the Program on International Student Assessment. Report Expand Download Print Share Share PDF: Why is Facebook not here? Why is Twitter not here? Share on LinkedIn Share on Google Plus Email Download or Print Permalink Copy Link Embed PDF: Copy Embed Code