The increased emphasis on a national effort was reflected in World War I recruitment methods. Peter A. Padilla and Mary Riege Laner define six basic appeals to these recruitment campaigns: patriotism, job/career/education, adventure/challenge, social status, travel, and miscellaneous. Between 1915 and 1918, 42% of all army recruitment posters were themed primarily by patriotism. And though other themes – such as adventure and greater social status – would play an increased role during World War II recruitment, appeals to serve one's country remained the dominant selling point.