Two sisters, novelist Kaitlyn Greenidge and playwright Kirsten Greenidge, spoke about weaving historical and personal influences into their fiction at the Harvard Book Store on Friday evening.

Both read excerpts of their work at the event, co-sponsored by Transition magazine of Harvard’s Hutchins Center for African and African American Research, before discussing the process of crafting pieces of historical fiction.

“I do feel like I have an obligation to the past,” Kaitlyn said. “I’ve had so many conversations with people from all walks of life about history, particularly black history.”

She described these conversations as sometimes strange and disturbing, and other times hopeful, but said that she wants to remain a part of these conversations.

The writers described how the amount of information involved in a particular historical moment can become overwhelming. They also discussed how best to achieve a balance between history and fiction in a piece.

“When it feels like you are writing a history paper, it is time to scale down,” Kirsten said.

She added that she is influenced by historical research as well as by her personal experiences. “I draw from parts of my life and parts of my family history,” she said.

The two spoke about their dynamic as a family of sisters who write creatively, referring to their third sister, who also writes.

“I get pure inspiration from how my sisters work,” Kirsten said. “It’s great to be in that close proximity with other writers and not feel that competition.”

When asked by an audience member to offer advice for aspiring young writers, they both emphasized the importance of finding a good “writers’ group” to provide constructive criticism and of consistently practicing your craft.

“I think that they are both clearly so intelligent in their separate fields of fiction,” said Matt T. Macca, one of Kirsten’s playwriting students at Boston University who attended the event. “It is really inspiring to hear two writers who are so strong in their voices and to see them interact.”

Kaitlyn contributed an excerpt from her forthcoming novel, “We Love You, Charlie Freeman,” to the most recent issue of Transition. Kirsten’s new play, “Milk Like Sugar,” will open in January at the Huntington Theatre in Boston.