In this article, Tony Russell-Rose explains autocomplete and autosuggest, and the differences between them. Any thoughts on how to apply both to the one search box and the one time? Any examples or research on this issue?
There is a different between Auto-Complete and Auto-Suggest.
Auto-Complete happens within the input box where you type and you can press either enter or "right-arrow-key" to accept it. Auto-Suggest list appears as a multiple suggestion list in the form of drop-down. To make use of auto-suggest items, you have to click "down-arrow-key" or mouse click to accept them.
If you want to implement them together, do something like that.
I think Google provides a good example of how it differentiates between the two. It provides two different types of text style when you type into the search input field. The darker text incorporate the characters that the user enters, and the light grey text are suggestions. You get both the text styling in the input box and also the dropdown, so I think that satisfies the criteria.
My preference would be to categorise them into sections/tabs/areas (don't forget a view all results link) because despite the example what @Salman gave you was good there's nothing to suggest that the user is unaware of the difference between the two search functions. That being said, does the user need to know this? If you want a good example of what @Salman was talking about this is brilliant: burton.com
Also a nice quote to prove what you're doing is right... According to Matthew Curry, E-commerce manager at Lovehoney:
“In my experience, autosuggest provides a real boost to search conversion rates. In a usability test I ran, we found that users actually relied upon site search autosuggest and autocorrect to know the correct spelling of words for them. Make sure that your site search solution is up to scratch, and that you still provide search results for common misspellings, just in case. “
Finally, here are a few different examples here that you might appreciate.