It is one thing to impart bare facts and information, and it is another to place the facts into a context whereby the reader can understand why a person, place, species, event, concept, etc., may be regarded as important. Nupedia articles should differ from some other encyclopedias by consistently highlighting the latter sort of information, when relevant. Claims about inventions, achievements, revolutions, assassinations, etc., can and should be placed in a broader context to explain why they do indeed deserve our attention.
Thus, for example, in a bibliographic entry, the author should indicate why the actions of the entry's subject are regarded as important; it should be made clear what impact, whether good or ill, those actions have had. Another example: entries concerning inventions and discoveries should relate some hard facts that make it clear how and why the invention or discovery has impacted the world. Why was the cotton gin so important, anyway?
An explanation of the importance of a topic is an opportunity to entertain readers. It is also one sort of area where some care will be necessary, because, obviously, there is considerable disagreement about what are properly considered achievements, and whether the results of given acts and events have been positive or negative. So it will be important to avoid bias in explaining why certain topics are important. It may turn out that for one segment of the educated populace, a particular topic is simply not important, while for another it is extremely so, and that this difference in assessment is due to political or religious reasons, for example. In such a case it should be made clear, in as unbiased a fashion as possible, for whom the topic is important, and why.