Despite its success, the project hit a stumbling block. When the school district reorganized recently, some of the most effective looping teachers moved into administrative jobs. Hampton has put the project on hold but plans to revive it.
Looping does have potential disadvantages. A personality clash between a child and a teacher or a teacher and a parent can lead to tension, but most schools say such situations are rare and can be resolved by moving the child to another classroom.
Bohr said knowing she must spend future years with her students provides an incentive for making the relationships work.
Another downside is that newcomers who enter a closely knit looping class can often feel disconnected for a time. And teachers must take the extra time to get up to speed on another year's curriculum. If they don't, instructional weaknesses could sorely hamper pupils.
Some teachers appreciate this challenge and prefer it to lecturing with the same material year after year.
"Nothing gets stale," Bohr said. "After my fourth year of teaching third grade in public schools, I felt like, 'OK, what do I need to change?' "
And perhaps the biggest compliment to looping comes from Jacobson's 11-year-old daughter, Talia, who on occasion accidentally refers to her teacher as "Mom."
"She'll casually go, 'Mom, I mean, Mr. Knauss,' " Jacobson said. "It just shows what an integral part he is in her life."
Times staff writer Ann L. Kim contributed to this story.