不比 vs 没有 comparison usage If my understanding is correct, then:


他没有我高。= he's not as tall as me, i.e. he is shorter.
他不比我高。= he's either as tall as me or shorter, i.e. he's at most as tall as me.


Is that correct? If so, in what situations would one use 不比? Is it when one is sure that a certain thing is no more than the compared one, but not sure if it is the same or less? Or do people just use it without thinking about it -- e.g. someone says 不比, but may mean 没有?
Your understanding is correct.

1. 他没有我高。-&gt; he &lt;  me
2. 他不比我高。-&gt; he &lt;= me


Comparing with the 1st one, the 2nd one is usually used for the situation to explain sb/sth is not bad relatively. Such as:

他不比我高。
-&gt; I'm as tall as him at least, he's not taller than me, connote that I'm not bad comparing with him.
本公司的技术水平已经不比国际上的一流水平差。
-&gt; Our technology level is not worse than international advanced level, connote that we're at the same level at least.