Write to your audience. There's no global answer. For instance, take a look at today's NY Times, USA Today and your local paper. You'll see varying lengths. The NY Times features long in-depth articles usually, because that's what their target reader wants. The USA Today features quick in and out stories, because their target reader is people on the go. Your local paper may have a mix or be something totally different. Shorter (as in total article length) isn't always better. Whether you're writing for readers in print or on the Internet, you've got to know your reader's characteristics and write to that. Also, you need to write to the topic. Some articles should be 50 words (briefs). Others should be far longer. The topic and your audience dictate the story's length. If the topic is too large for the desired space, drill down. You can jump stories if you wish (also called breaking them down). That's what print does and it generally works okay. Just make sure you break at logical points. I definitely wouldn't recommend publishing a 1500-word story as a one pager.