统计数字用以显示某种情况统计计算的结果，它们也能给人留下深刻的印象，并且有说服力，特别是它有证据的效用，是孤立的事例所不能达到的。沙克预防小儿麻痹疫苗能被认为确实有效，是依靠来自全国各地的统计数字而得到确认的。个别无效者只是例外，因而根据这样一个例外而发的议论，便不能让那些父母相信沙克疫苗不能保护自己的孩子。Statistics are used to show the proportion of instances of a certain kind. They can be impressive and convincing, especially as evidence where an isolated example might not do as well. The effectiveness of the Salk anti-poliomyelitis vaccine program was measured by statistic gathered in all parts of the country. Isolated cases of ineffectiveness were the exceptions that proved the rule. A talk based on one of these exceptions would not, therefore, convince a parent that the Salk vaccine program would not protect his child.
但是数字本身却是令人厌烦的，所以又应该明智而审慎地使用，使用时应该给它穿上语言的外衣，让它鲜明生动。Statistics, of themselves, can be boring. They should be judiciously used, and when used they should be clothed in a language that makes them vivid and graphic.
这里有一个例子，说明了把统计数字和我们熟悉的事物进行比较，就能收到加强印象的效果。一位主管认为纽约人太懒，由于不立刻去接听电话，造成大量的时间损失。为支持自己的论点，他说：Here is an example of how statistics can be impressive by comparing them with things familiar to us. In backing up his point that a vast amount of time is lost by New Yorkers, neglecting to answer telephones promptly an executive said:
“每100通电话当中，有7通显示，要超过1分钟的耽搁接听电话的人才拿起话筒。每天共有280000分钟损失在这种方式之下，如此6个月，纽约耽搁的时间便差不多与自哥伦布发现美洲以来的所有交易日时间相等。”Out of each one hundred telephone connections made, seven show a delay of more than a minute before the person called answers. Every day 280, 000 minutes are lost in this way. In the course of six months, this minute delay in New York is about equal to all the business days that have elapsed since Columbus discovered America.
只提出数字、数量本身，是不会留给人什么印象的，它们必须辅以实例。如果可能，必须给它们加上我们自己的经验来讲述。我记得在大坝水库下面的大发电房里，听过一个导游的解说。他本可以告诉我们这个房间面积的数字，但是这与他所使用的方法相比，说服力可就差得多。他告诉我们，这个房间的面积足够容纳一万人在标准的球场上观赏足球赛，另外每边还有余地可用做数个网球场。Mere numbers and amounts, taken by themselves, are never very impressive. They have to be illustrated; they ought, if possible, to be put in terms of our experiences. I remember listening to a lecture by a guide in the vast power room under Grand Coulee Dam. He could have given us the square-foot figures of the room's size, but that would not have been so convincing as the method he used. He told us that the room was large enough for a crowd of 10,000 people to view a football game on a regulation field and, in addition, there would be room left over for several tennis courts at each end!
多年前，我在布鲁克林中区青年基督教协会的演讲班里有个学生，他在某次讲演中提到了去年毁于火灾的房屋数目，并进一步解说，如果这些他烧毁的建筑并肩排放，可由纽约排到芝加哥。而且，如果将死于火中的人们，每0.5公里放置一个，这条愁惨的长龙便又可从芝加哥排回布鲁克林。Many years ago, a student in my course at the Brooklyn Central YMCA told in a talk the number of houses destroyed by fire during the previous year. He further said that, if these burned buildings had been placed side by side, !he line would have reached from New York to Chicago, and that if the people who had been killed in those fires had been placed half a mile apart, that gruesome line would reach back again from Chicago to Brooklyn.
他所列举的数字，我几乎入耳即忘，但是过了这么多年，我却毫不费力，依旧心有余悸地看到那一长列燃烧中的建筑，一路由曼哈坦岛延伸至伊利诺伊州的库克县。The figures he gave I forgot almost immediately but years have passed, and, without any effort on my part, I can still see that line of burning buildings stretching from Manhattan Island to Cook County, Illinois.
