Went to go do a voice-over at the Bank the other morning--they needed it fast, and their usual go-to people had gone-to somewhere else. Turns out it was an old script that I'd actually recorded with someone else in the voiceover chair about a year ago. So fortunately for me, most of it (excepting the changes and additions) had already been edited for speech.
I could tell where they had added new paragraphs. Not because I remembered it, but because they do not use a serial comma. Now, there are people who believe that the serial comma is incorrect, including (sadly) many journalists and newspaper style guides. These people should never be allowed within 90 feet of a voiceover script. I personally feel that the serial comma is just good writing because it is usually less ambiguous than the alternative. Regardless, in voiceovers and speechwriting, it should be mandatory. I feel very, very strongly about this.
A common reason for including the serial comma in writing is to mimic the pacing of the spoken word. When reading from a script, it works the opposite way: the written work needs to be paced so that it can be quickly and effortlessly parsed by a reader. Try it yourself! Read the following sentence aloud:
To evaluate behavior, we can consult with supervisors to determine if staff are demonstrating the newly acquired knowledge, habits, skills or behaviors.When reading a list in English, the last item is usually emphasized differently from the items in the middle--it's given a kind of "full stop" treatment. Without the serial comma, it's easy to skip over that emphasis and nonverbally combine skills and behaviors into a single list item, particularly if it coincides with a line break. This is confusing for listeners--and more importantly, it will frustrate good VO talent, who will want to use precious session time and vocal energy to do the line over properly.
To sum up: Good punctuation will keep your voiceover talent from killing you. Save lives. Use the serial comma.