The ABCS of HCI t8Guidance for Interactive System Designers ** This book is superceded by a later, better version, details at http: www. frankritter. com fducs. ** This version is still available in case you are finding it through an old link, and we think some of you are. You would be better getting the other version, this is just a pointer to an older version. Any profit from this version on lulu will either be given to LuLu or the State College Community Land Trust.