Day12 Advertising the reduced price of selected grocery items in the Daily Gazette will help you increase your sales
The following appeared as part of a promotional campaign to sell advertising space in the Daily Gazette to grocery stores in the Marston area：
“Advertising the reduced price of selected grocery items in the Daily Gazette will help you increase your sales.Consider the results of a study conducted last month，thirty sale items from a store in downtown Marston were advertised in The Gazette for four days.Each time one or more of the 30 items was purchased，clerks asked whether the shopper had read the ad.Two-thirds of the 200 shoppers asked answered in the af firmative.Furthermore，more than half the customers who answered in the af firmative spent over$100 at the store.”
Discuss how well reasoned you find this argument.In your discussion be sure to analyze the line of reasoning and the use of evidence in the argument.For example，you may need to consider what questionable assumptions underlie the thinking and what alternative explanations or counterexamples might weaken the conclusion.You can also discuss what sort of evidence would strengthen or refute the argument，what changes in the argument would make it more logically sound，and what，if anything，would help you better evaluate its conclusion.
文勇五问：
（1）本题中，事实是什么？结论是什么？“thirty sale items from a store in downtown Marston were advertised in The Gazette for four days.Each time one or more of the 30 items was purchased，clerks asked whether the shopper had read the ad.Two-thirds of the 200 shoppers asked answered in the affirmative.Furthermore，more than half the customers who answered in the af firmative spent over$100 at the store.”是事实，“Advertising the reduced price of selected grocery items in the Daily Gazette will help you increase your sales.”是结论，值得反驳吗？
（2）上个月的研究数据具有代表性吗？一定适用于未来吗？这里是否犯了时间轴论证的错误？
（3）200个样本的量足够吗？三分之二是否能够代表大部分人？剩下的三分之一呢？是否犯了调查研究时最容易犯的大数谬误？
（4）顾客购买特价商品，一定是因为看到了广告吗？是否还有其他可能的原因？有没有可能是因为朋友推荐或生活需要、看到广告前就已有打算要购买呢？
（5）超过半数看过广告的顾客消费超过100美元以上，这个数据与这些顾客平时的开支和其他没看过广告的顾客的开支相对比，是更高、更低、还是持平？如果是更高，是否有证据可证明和特价商品广告有直接因果关系呢？
写一写，练一练
