Ms. Nelson said most of her members’ clients were retirees who finally had the time to reflect on their lives. Many need help digitizing the past — scanning dog-eared photographs, curling birth certificates and frayed Valentine Day’s cards, as well as transferring material from obsolete storage formats like cassette and VHS tapes. She added that current formats — hard disk drives, DVDs, even cloud storage — also cannot be relied upon for permanence, so it is essential to have a plan in place to keep archives current as technologies evolve. She said the printed book, paradoxically, remains one of the most enduring formats.

As her clients work to organize and make sense of these mountains of material, Ms. Nelson helps them distinguish between the small number of shots worth featuring in an album, the next tier still worth keeping and the many shots that belong in the trash. “I’ll usually take the trash bags home with me so they don’t go back and try to retrieve them,” she said with a laugh.

Finally, they arrange the photos and video clips, writing captions and recording voice-overs, so they tell a story. “I try to help people determine the goal,” Ms. Nelson said. “What is the main story they want to hold on to? What are the themes of your life? For instance, did you go on vacation every summer to the Cape? What is the story behind the summer vacation? Let’s gather everything you have from that to tell a story.”

Mary O’Brien Tyrrell, president of the International Institute for Reminiscence and Life Review, has taken a similar approach to assist budding memoirists. She said her institute was inspired by the work of Robert N. Butler, the gerontologist who coined the term ageism, and the psychiatrist Dr. Gene D. Cohen. Before Dr. Butler began his work in the 1960s, Ms. Tyrrell said, “doctors often discouraged older people from reminiscing because they thought it would lead to senile dementia.”

Dr. Cohen believed that reflection was a natural stage of life. “Just like you know a baby should be up and walking at 1, when they get to be 80 they should be taking time to think and reflect back — the summing-up stage,” Ms. Tyrrell said. “This not only helps them see what they have done but helps them plan their next steps.”

Dan Schuette, a 70-year-old retiree who lives in Sun Prairie, Wis., said he was surprised and inspired while writing 15 autobiographical stories he published in a book for his family. “I realized that I’ve had a pretty good life,” he said. “It also made me focus on what I still want to do. I visit the graves of my father and my 12-day-old grandson who died and have conversations with them. I realized that if I want my kids and grandkids to come see me at my grave, maybe I should be a larger part of their life, maybe I should get in my car and see them when it isn’t so convenient for me, or make another call.”

Stefani Twyford, who creates video biographies through her company, Legacy Multimedia in Houston, said many of her clients were baby boomers who wanted to record their own parents’ lives. “There is a real sense that we can finally get these stories down and they want to act before it’s too late,” she said.