For the 50th reunion of the Sacramento High School Class of 1962, organizer Tricia Brown had big plans: cocktail hour followed by a buffet in a Woodlake Hotel Sacramento ballroom decorated in purple and white, the school colors - a glittery and festive occasion.
"I see the reunion as a walk down memory lane," said Brown, 67, a retired elementary teacher who lives in east Sacramento. "It's fun to see people who knew you then."
She has a Facebook account, which she uses mainly to keep up with relatives out of state - but she can't imagine why anyone would prefer seeing classmates online instead of in person at a reunion. Frankly, the idea bewilders her.
"You wouldn't go to the reunion because of that?" she said.
That's exactly the fear of people planning high school reunions: In an age of soaring social media use, when people can reconnect with long-lost and perhaps faraway classmates through Facebook and other sites, has the time-honored tradition of the reunion seen better days?
Experts say that attendance at the 10-year high school reunion has dropped in recent years. In general, a good reunion attendance is 25 percent of the graduating class, said National Association of Reunion Managers President Cyndi Clamp. Now, in her own St. Louis-based business, Varsity Reunions, the average number of attendees has dropped below 20 percent.
Even for people in the reunion business, it's hard to figure out why this is happening, and whether Facebook or the economy is to blame. Yet reunion planners say young alumni simply don't seem to feel the urgency of catching up in person when they've already caught up plenty online.
There is no question that Facebook's influence continues to grow. The site reaches 72 percent of all Americans on the Internet, according to the blog Digitalbuzz. At the end of March, it had 526 million active daily users around the globe, double the number two years earlier.
While almost half of the people on Facebook are in the 18-to-34 age group, 30 percent are 35 and older. They include people who use the site as a way to keep up with their kids and grandkids, as well as people who sign on to reconnect with high school and college classmates from decades earlier.
In some ways, Facebook has created more buzz about reunions. Alumni form online groups for the purpose of planning and communicating ahead of time, and also keep in touch afterward. Whether this planning actually causes more people to show up is an open question.
"If you don't have a real community of people who feel connected anyhow, the best social media won't channel them to the reunion," said Andrew Shaindlin, assistant vice president for alumni relations at Carnegie Mellon University and author of the AlumniFutures blog.
Shari Sigl, 43, said she's seen evidence of the Facebook effect among her classmates. Sigl is helping organize the Foothill High School Class of 1987 reunion in August.
"Because of Facebook, I see people interested in the reunion now who haven't been before," Sigl said.
"I'm not sure that makes them want to come to the reunion," she added. "People are already in touch. Why pay money for it?"
That's the crux of the issue, not to mention the source of debate among event planners.
Some, like Clamp, think that introverts, party poopers and people with unhappy memories of high school are using Facebook as an excuse to avoid attending their reunions.
"My perception is, most of these people were never going to attend the reunion anyway," she said. "They just say it's because of Facebook."
On the other hand, Christian Brothers alumni relations director Nancy Smith-Fagan said: "I find that social media is really good at raising awareness, but it doesn't necessarily move people to act.
"There has to be a combination of things to get people to the next step."
For alumni who have moved across the country, high airfare and hotel costs - not to mention the need to burn up vacation time on people they haven't seen for decades - may tip the equation in favor of Facebook-only interactions. People have already rekindled friendships with high school friends through social media, so why invest in attending the reunion?
"I know a couple of people out of town who feel (that) way," said Don Nahhas, 48, one of the planners of the upcoming Hiram Johnson High School Class of 1982 reunion. "But we do have people who want to meet face to face, too."
For now, the Sacramento High School Class of 1962 remains on the other side of the digital and social media divide between the generations.
Planning committee member Brian Fletcher, 67, who is retired from the biotech industry, set up the class's online presence on a boilerplate reunion site, which proved confusing for some of his classmates.
"Some people have had trouble navigating the pages," he said. "They see things and don't know they're links they can click. They email or call for help."
Out of 625 surviving class members, at least 160 were expected for last Saturday's reunion. It's not a bad turnout by industry standards - and maybe it's a testament to the importance of face-to-face interactions.
"I want everybody to come and be happy," said Tricia Brown. "Some people really think it's a privilege to go to your 50th reunion and talk about your memories."