Frances R. Horwich, known to millions of preschoolers in the 1950s and ’60s as Miss Frances on “Ding Dong School,” which helped change children’s television and led the way for shows like “Sesame Street” and “Mr. Rogers Neighborhood,” died Sunday of congestive heart failure in Scottsdale, Ariz. She was 94.First aired in 1952 on Chicago’s WNBQ Channel 5 (now WMAQ), “Ding Dong School” was unlike other early children’s TV shows in that producer-host Horwich, an educator with a doctorate in education, engaged the young audience members by interacting with them — and speaking to the parents. After beginning each program by ringing an old-fashioned teacher’s bell, she’d looked into the camera and ask, “How are you this morning?” Then she’d give children in front of their TV sets time to respond. She also led children in crafts, songs and storytelling with puppets Jocko the monkey and Lucky the rabbit. The show was such a hit that in about six weeks, NBC decided to broadcast it nationally, and ran it for four years. NBC also named Horwich the supervisor of all children’s programming. “Ding Dong School” won a George Foster Peabody Award. The show moved from Chicago to New York and later Los Angeles, where it went into syndication until Horwich retired in the 1960s.