I am attempting to take an existing presentation and use the information
within it to create the corresponding outline. I continue to get duplicate
text on the slides when trying to paste the text into the outline. How can I
correct this?
Here's how PowerPoint works:
Text you enter into the outline appears in the Title and or Body Text
placeholders on slides.
Text you enter into those placeholders appears on the outline.
It sounds like your slide text isn't in placeholders. Generally you want it
there (easier to format) so if it were mine, I'd paste the text into the outline
then delete it from the slide, leaving the text in the placeholders behind.
If you don't want to do that, you can do View, Master, Slide Master and drag the
title and body text placeholders off the slide. Then when you put text in the
outline it'll appear in the placeholder, but since that's not on the slide, it
won't appear during a slide show.