About twenty years ago, Karina Reyna and her twin sister both had Tan as their first-grade teacher, an experience Reyna still remembers vividly.
The girls had been born in Mexico and entered the U.S. illegally with their parents, neither of whom had graduated from high school. The family lived in a working-class area in San Fernando, where Reyna's father installed carpets.
By first grade, Reyna said, she still didn't speak English. Ms. Tan was determined to change that.
"I really didn't like her," Reyna recalled. "I remember crying every day."
Tan pushed Reyna relentlessly, accepting nothing but her best work. Reyna's English improved, but when she continued to struggle in math, Tan stayed after school to help her catch up.
"Now I recognize it wasn't mean, it was strict," Reyna said. "She was pushing me to do what I was capable of. Maybe she even saw something I didn't see."
Reyna and her sister Daniella stayed in touch with Tan over the years. Tan attended their 15th birthday party and years later Daniella's 2006 graduation from Cal State Northridge, which both sisters attended after becoming U.S. citizens.
"I don't think I'll ever forget her," said Reyna, who works for an insurance company and plans to finish her college degree soon. "Without her, there wouldn't have been somebody saying, 'You have to finish school; you have to go to college.' "
When Reyna learned that her daughter, Jazmin, had been assigned to Tan, she was convinced the girl would thrive.
"I told her, 'She's really strict,' " Reyna recalled. " 'You're going to be pushed, but it's going to be good for you.' "
She was right.
Jazmin entered Tan's class in 2007 above grade level in math. By the end of the school year, she had vaulted 74 points to 600 on the state test -- a perfect score.
Having just finished fifth grade, Jazmin was recently accepted into a gifted-magnet middle school. Reyna expects her to graduate from college and go into medicine. She hopes her son, a kindergartener, will also be assigned to Tan.
"She pushes kids to be their best," Reyna said.
Only two options
Tan measures her success in stories like these.
But by the LAUSD's measure, Tam simply "meets standard performance," as virtually all district teachers do -- evaluators' only other option is "below standard performance." On a recent evaluation, her principal, Oliver Ramirez, checked off all the appropriate boxes, Tan said -- then noted that she had been late to pick up her students from recess three times.
"I threw it away because I got upset," Tan said. "Why don't you focus on my teaching?! Why don't you focus on where my students are?"
Ramirez said he wants to give more recognition to his excellent teachers, but with no objective measure to rely on, he's concerned about ruffling feathers.
"What about the teachers who feel they should have been recognized?" he said. "There'll be a whole mess. The district knows this would open up a can of worms."
"That's why it doesn't happen."
Times staff writer Doug Smith contributed to this report.