Seventy-three schools are appealing the letter grades they’ve been given by state school officials, citing a variety of reasons that their grade should be improved.

For about two-thirds of those appealing, school officials say either that the Arizona Department of Education used incorrect data to calculate their letter grade or that the formula the Arizona State Board of Education used to grade schools is flawed.

Four schools say the teacher shortage in Arizona resulted in their poor letter grade.

Other appeals blame road construction, building construction, plumbing problems, air conditioning problems or an outbreak of the flu for their letter grade.

A small number of schools cited unusual conditions.

• Flagstaff High School received threats of “Columbine-style” violence, resulting in a spike of absences while parents kept their kids at home.

• Casa Grande Union High School explained that its principal was in China when data was provided to the Department of Education, and that the school’s staff did not include all the data.

• George Gervin Prep Academy described several specific teachers at the school who caused problems for students and needed to be disciplined or removed from the classroom. One teacher, the school administrators said, was “immensely affected” by and became erratic following the election of Donald Trump as president. Another, they said, bullied and intimidated students.

The Board of Education said they plan to review the appeals and make decisions on them in coming months, but do not have a firm date for when that process will be completed.

Additionally, the Board of Education announced this month that it will revamp the formula used to calculate the grades and issue a new set of “final” grades later this year.