在科学写作中，下列哪个句子是正确的?
- The mean score among the students was 20. The score among the staff was 10 however.
- This study used a small sample. Our previous study however used a large sample.
- This interview study reveals varied responses from 10 students, however small group data cannot be generalized.
- The interview responses from the students however small the group reveal problems with the new policy.
这些句子都可以改进。首先，“however”可以是表示对比的副词，在句中位置较灵活。在句子（1）中，在最后一个词“however”之前添加一个逗号，有助于将对比表达清楚：“The score among the staff was 10, however”。当表示对比的“however”出现在句子中间时，比如句子（2），两边都加上逗号可以更清楚：“Our previous study, however, used a large sample.”与“In contrast,…”或“By contrast,…”类似，“however”也可以移到开头，后面跟一个逗号：“However, our previous study used a large sample.”
其次，“however”可以是让步副词（承认相反），如“nevertheless”、“still”、“at the same time”或“in spite of that”。在句子（3）中，有两个独立的子句，每个子句可以是一个完整的句子，因此在“however”之前需要一个完整的句号或分号。有些作者在“however”在句首时后面不加逗号，但加了逗号更清楚。在形容词“small-group”之间加一个连字符更好：“However, small-group data cannot be generalized.”
第三，“however”可以是程度副词，意思是no matter how，如句子（4）。它也表示让步，但在“however”和形容词“small”之间没有逗号。因为短语“however small the group”是额外的信息，应该放在一对逗号之间：“The interview responses from the students, however small the group, reveal problems with the new policy.”
