為數不少的選舉研究指出，大眾傳播媒介的使用頻率與選民對政治活動的認識有正相關的關係。而各種文獻也曾指出，那些已決定投票對象的選民要比尚未作最後圈選決定的人，有較深刻的選情認識。本研究即在嘗試解釋媒介使用、圈票意向決定與選情認知三者之間的關係。應用之資料分兩組。一組是於一九七四年美國國會選舉時在美國南伊諾州搜得之資料；另一組則為一九七六年美國總統大選時在東南密蘇里州搜得之問卷資料。結果顯示，已決定投票意向的選民對政見與候選人的認識是高過那些尚未作圈選決定的選民。而使用大眾傳播媒介較多的人，不論其是否曾改變圈選意願，都不比那些使用媒介少的人有較多的選情認知。 Voting studies have reported a positive association between attention to the media and levels of knowledge about political events and that decided voters know more than do those who are undecided. The literature also indicates, on a less substantive basis, that vote switchers have lower levels of political knowledge than do those who do not switch candidates. Many studies, if not most, have used measures of political opinions, interest, or involvement as measures of knowledge; other studies have lacked clear-cut tests of the relationships. The present study employs reasons voters give for voting for or against specific candidates and reported voter perceptions of campaign issues as measures of political knowledge. Comparisons of the relationships between voting status and knowledge are made under two levels of attention to the campaign. The data were collected in a 1974 congressional campaign and the 1976 presidential campaign. The findings support earlier studies regarding the differences in knowledge levels between decided and undecided voters for both candidate and issue knowledge. However, no significant difference in candidate knowledge levels was found between switchers and non-switchers in either the congressional or the presidential campaign. Those who did not switch candidate preference in the 1976 campaign reported higher levels of issue knowledge than did those who switched candidate preference. The relationship between knowledge level and attention to the campaign via the mass media varied with voting status and campaign.