Whatever happened to your best friend who moved out of state when you were both in the eighth grade? At one time, the process of finding a long-lost pal involved a lot of phone calls and knocks on doors. Often, the search would be fruitless. In the 21st century, though, searching has gotten easier. The internet is your friend.

It's often a good idea to begin your search by writing down whatever you know about your friend – her name, the names of her parents and siblings and information about school and work. You probably had several friends in common. Note those names too. What were your friend's particular interests? Music? The arts? Sports? Any personal details you can remember may well be useful, particularly those involving unusual activities or interests.

One good way of organizing your search is to think of it as reconnecting a network, beginning with the closest connections first. If you're able to connect with one or more of your friend's family members, your search may end successfully at that point. Similarly, if you're able to find friends in common, one of them will often give you a direct connection or, if not, additional information that will help your search.

Getting in touch with any of your friend's former employers is sometimes useful, although company policies often won't allow disclosure of information beyond name and dates of employment. Schools your friend attended may give helpful information if their policies allow such sharing.

If these close connections don't give you the information you need, turn to social media on the internet, which can be helpful in two ways. First, you may find your friend active on one or more of the social media sites, in which case you can reconnect simply by posting a greeting and asking to reconnect. Second, if your friend isn't active on one of these sites, you can try posting an inquiry on the sites yourself. This can be surprisingly effective, because you're now asking literally millions of others to help.

The 15 largest social media sites (in order of number of participants as of November, 2017) are:

1. Facebook (over 2 billion members)
2. YouTube (about 1.5 billion)
3. Instagram (800 million)
4. Twitter (330 million)
5. Reddit (250 million)
6. Pinterest (200 million)
7. Vine Camera (200 million)
8. Ask.fm (160 million)
9. Tumblr (115 million)
10. Flickr (112 million)
11. Google+ (111 million)
12. LinkedIn (106 million) 
    
13. VK (97 million)
14. Classmates (57 million)
15. MeetUp (32.3 million)

Becoming a member of all 15 of these social media groups is beyond the scope of this article, but by design, they're all easy to join. To create a Facebook account, for instance, go to Facebook.com and indicate on the home page that you want to sign up. Enter your name, email address or mobile number, birthdate and gender, then create a password and click on "Create an account." Finish the process by confirming your email address or mobile number. And that's it. Start your friend search by typing in her name.