At the school I first attended after home schooling. Porum Junior High/High School, in Oklahoma, a lot of the teachers used overhead notes. Most of them were okay at it, but some were just pathetic. My 8th grade Reading teacher, let's call her Mrs. Wrong, was particularly bad at this note-giving method. She kept her transparencies for years, but didn't take great care of them. A lot of the information was outdated. Her handwriting was so hard to read; she was a 60 year old woman who wrote strictly in cursive. And she used them everyday.
I had another teacher that used transparencies and an overhead, but he knew what he was doing. This teacher was from here in Wichita. He always wrote fresh notes every year. He took care of them. His handwriting was legible. And best of all: he used them about 25% of the time, instead of everyday.
