Someone emailed a question seeking guidance for how to determine the best length for scenes. She said her CPs were complaining that her scenes were too long, and she wasn't sure why they were making that comment.
Scene length is tricky because each scene is different. There's no set template for scenes or even for types of scenes. But if people are saying, "Your scenes are too long," that might mean they're literally physically too long, or it might mean there's a pacing issue within a scene that is a more or less appropriate length. These are related problems, of course, because if a scene goes on for 5k words and all they do is check their calendars to see when they're both free for coffee, chances are the length problem stems from a pacing problem.
How do you know when it's a pacing problem? Pacing problems occur when the story elements are not given an appropriate amount or type of attention in the text. To diagnose a pacing problem, start by identifying the important story elements in a scene. The more important an element is, the more space it should occupy on the page. (This assumes you're not trying to hide an important detail in plain sight, as sometimes happens with mystery clues. In that case, minimize the amount of page space granted to that detail.) Less weighty details should occupy less page space.
However, there's more to it than just the amount of page space. We also have to look at the type of narrative element being used to reveal the story element. So, let's say the story element is a bit of action -- someone does something in the physical world of the scene. Action is usually faster paced just by its nature, but it's possible to slow it down by revealing the character's physical movement through dialogue or exposition instead of through action.
Right then, Aaron pulled the trigger. (action)
"I am pulling the trigger right this second," Aaron said. (dialogue)
Aaron realized this was the appropriate time to use a pulling motion against the trigger. (exposition)
So, we've said that important story moments require more space on the page in order to carry their own narrative weight, but in this case, the longer the sample sentence gets, the slower the pace gets. What makes it slow down? Instead of directly conveying movement through action, it's being translated into another element, and the reader will have to mentally translate it back from dialogue or exposition to actual physical movement. This creates a drag on the pacing.
So, pacing is a complex issue that requires careful appraisal, and the general principles of pacing and length sometimes work against each other. That said, we can still formulate some very broad ideas about how long a scene should be.
Broad Idea #1:
If a scene is built around action and dialogue, it can be a bit on the long side.
Broad Idea #2:
If a scene is built around description, interior monologue, or exposition, it can be a bit on the short side.
These first two broad ideas work from the equally broad ideas that action and dialogue are faster (so you can have more of them before they feel slow), but description, interior monologue, and exposition are slower (so you should scale back on them to prevent a pacing drag).
Broad Idea #3:
The more the reader's emotions will be engaged, the longer the scene can be.
The reader's emotion can result from sharing the characters' emotions (as in a fight scene or a love scene), or it can occur from scene tension (as in a scene where the reader is on edge about what will happen next).
Broad Idea #4:
Modulate both the pace and the length of scenes.
Unless you're writing something meant for serialization and have strict format requirements, use a mix of lengths and paces to avoid a repetitive tone in the text.