premise: In those countries where dialect study is undertaken , dialectologists observe that there are today many factors militating against the strict maintenance of older dialect the standardization of terminology as adopted by national periodicals , news services , radio , and television ; the establishment of prestige dialects and , through the media , their promulgation ; and the huge population shifts that have taken place , particularly in the U.S. since WWII .
hypothesis: Outside of the U.S. , this phenomenon is most prominently seen in the other countries inovlved in WWII .