Hammond S L, Freimuth V S, Morrison W
Health Educ Q. 1987 Summer;14(2):153-66. doi: 10.1177/109019818701400203.
This article presents the gatekeeping funnel as a model of the process that a public service announcement (PSA) goes through from distribution until it reaches its target audience. Process measures such as bounceback postcards, the Broadcast Advertisers Report (BAR), and analysis of audience response are suggested as ways of monitoring this funneling process. The model is then applied to the National Cancer Institute's PSA campaign designed to promote cancer prevention awareness. Three waves of PSAs were distributed between March 1984 and May 1985. Two of these waves of PSAs were targeted to the general public and the third wave was targeted to black audiences. Bounceback postcards, BAR data, and the Cancer Information Service (CIS) call data exemplify the gatekeeping funnel model described in the article. When the messages were distributed, they had the potential of reaching 170 million adults with televisions. BAR data show that the gatekeeping function narrowed the number of people potentially exposed to the messages to 24 million, or 14% of the total. Yet only 144,000 people, or less than one-tenth of 1% responded to the messages by calling the CIS number and asking about cancer prevention. This analysis may help PSA campaign planners to develop more realistic expectations for message effects.
本文提出把关漏斗模型，用以描述公益广告（PSA）从投放至抵达目标受众的整个过程。文中建议采用诸如回复明信片、广播广告商报告（BAR）以及受众反应分析等过程指标，来监测这一漏斗式流程。随后，该模型被应用于美国国立癌症研究所旨在提高癌症预防意识的公益广告活动。在1984年3月至1985年5月期间共投放了三轮公益广告。其中两轮面向普通大众，第三轮则针对黑人受众。回复明信片、BAR数据以及癌症信息服务（CIS）热线数据，均例证了本文所述的把关漏斗模型。广告投放时，其潜在受众为1.7亿成年电视观众。BAR数据显示，把关作用使可能接触到这些广告的人数缩减至2400万，占总数的14%。然而，只有14.4万人拨打CIS热线咨询癌症预防问题，占比不到千分之一。这一分析有助于公益广告活动策划者对广告效果形成更现实的预期。
