Difficult: Easy
Many Uni-edit customers are from Chinese & Japanese language backgrounds. Our customers sometimes translate the characters “一方” or “一方面” into English as “on the other hand” and “besides” synonymously. However, these words have quite different meanings in English.
On the other hand
“On the other hand” is used to present factors that are opposed, or that support opposing opinions. It suggests the author is deliberating, or in the process of making a decision. "On one hand ... On the other hand..." is a commonly used and natural structure.
Correct: Some researchers have suggested metallic carbon nanotubes as a potential material for the construction electrical circuits like those in computer chips. Metallic carbon nanotubes possess high thermal stability, thermal conductivity, and current carrying capacity. On the other hand, their fabrication is a challenging and time-consuming process, and there is no suitable mass production method at present.
Besides
“Besides” is used to introduce an additional idea or explanation. It suggests the author has already made his decision; reasons with “besides” are just more evidence for a decision that is already known to be optimal.
Correct: Based on this evidence, we did not employ metallic carbon nanotubes to construct our chips. Besides, the speed of existing technology is suitable for our purposes.
Because “besides” gives an after-the-fact reason for a finding, it can sound dismissive or even prejudiced. In fact, careful academic writers rarely use “besides”, because inserting extra, unnecessary reasons dilutes the original argument.
Saying “moreover” or “in addition” is a sensible alternative that does not imply rationalizing. That implies the additional fact supports the main argument or line of reasoning.
Correct: Based on this evidence, we did not employ metallic carbon nanotubes to construct our chips. Moreover, the speed of existing technology is suitable for our purposes.