方法实战：信息来源与证据可信度

唯一新困难：信息来源与可信度

文章会并列研究结果、机构声明、个人经历和作者判断。它们的“声音”不同，证据权重也不同。题目常把企业自述写成独立验证，或把作者引用的质疑当作作者结论。本课只训练“谁说—依据什么—能支持多强”。

自拟短文

A software company says its scheduling tool reduces employee stress. The claim comes from a survey sent to customers who renewed their subscriptions. An independent research group notes that satisfied customers may have been more likely to respond and that firms cancelling the service were not included. The group does not conclude that the tool is ineffective; it calls for a comparison including both users and former users.

题目：Why does the research group question the company's claim?

A. The survey may overrepresent satisfied continuing customers.
B. The company collected no customer opinions.
C. Every former user reported higher stress.
D. Scheduling tools cannot be studied.

来源审计

公司提出效果主张，证据是续订客户调查。独立小组指出两个选择偏差：满意者更可能回答、取消者未纳入。A 准确概括。

B 与 survey 存在冲突；C 把“未纳入”偷换成“全部负面报告”；D 从需要更好比较扩大成无法研究。

可信度不等于真假标签

独立小组没有断言工具无效，只认为现有设计不足以支持强结论。正确态度是“证据有限，需更完整样本”，不是在公司与研究者之间凭身份站队。

迁移练习

若文章写 according to the manufacturer，选项能否改成 independent tests proved？

**答案：**不能。信息来源从制造商自述被偷换成独立验证，证据等级显著加强。

独立动作验收

列出两种声音、各自依据、研究小组支持与不支持的结论。答案只说“样本有偏”但不指出偏向谁，不通过。