Scroll down to look at the first 10 articles about "instant messaging."  The results are in date order; that is, the most recent article is at the top of the list.  As you go down the list, the results get older and older. 

So the article at the top of the list is not necessarily the best article; it is just the most recent. 

ProQuest Central found 23225 articles that have the phrase instant messaging somewhere in the record.  You can see that number between the box that says "Suggested Topics About..." and the numbered list of articles.

Beneath that, you can see a tab that says "All Sources," followed by tabs for "Scholarly Journals," "Magazines," "Trade Publications," etc.  Right now we are looking at "All Sources," all the articles combined in one list.    

Now click on the tab that says "Scholarly Journals."  It will show you the subset of academic articles on instant messaging.