A group of scholars in Oklahoma have reviewed the state’s simplistic A-F report cards for schools and proposed a better way to look at school effectiveness. The Tulsa World provided a link so perhaps many people in the state will see it.
Jeb Bush pioneered this grading system on Florida. It puts far too much emphasis on test scores.
Three worthy parts of the review:
1. The fact that these scholars did this report matters
2. Good bibliography
3. Conclusion:
“The work of schools and school leaders might be compared to gardening, that is, tending to the growth of a great variety of life. Gardeners are not preoccupied only with the harvest alone. They bring to bear all kinds of knowledge, skill, and information, adjusting what they do constantly to enrich the environment of the garden, providing nurture and protection from everything that might harm it. Gardeners know that the harvest at hand is important, but that care for soil conditions, monitoring surrounding vegetation, and assuring availability of supplementary water and fertilizer are just as important; future harvests will benefit from the enhanced general conditions of the garden. The metaphor suggests that accountability in schools cannot be defined in the same way quality assurance is attained in manufacturing. Schooling more resembles what Thomson (1967) calls an intensive technology, in which the processing of nonstandard raw material relies on constant response to new information. The metaphor and the theory both point to accountability for process elements and capacity building as well as outcomes; a focus on outcomes alone would not adequately serve the complexities of schooling or the long-term goals of our society. The collaboration among Oklahoma’s education stakeholders could benefit by a metaphor that reminds us of the importance a long- term perspective has for effective school improvement.”
Diane Ravitch's blog 
This is one of the best reviews I have read regarding the “indexing” or grading of schools.
I hope the “reformers” and the educational lawyers are taking note.
Here’s an excerpt:
“The State’s claims that its grading system is simple and clear are not justified. Simplicity, or parsimony, refers to the ability to portray the truth with the fewest words. Two criteria
are required for clarity: brevity and truth. The letter grade is not simple, but simplistic, that is, it meets the brevity criterion, but fails the truth criterion. It does not present adequate information and thus portrays a partial truth. Instead of informing and empowering the public about school performance, it provokes the public with grades whose meaning is unclear, moving it to conclusions that are unjustified.”
“To be a clear representation of a school’s performance, the grade must capture performance that is the consequence of what the school does and not other things. It should not, for example, vary as a result of conditions the school does not and cannot control, for example concentrated neighborhood poverty. If it cannot be claimed that the grade is the result of the school’s efforts only, then the measure contains error, contributing to its lack of clarity.”
I will say, this report really gets to the heart of the problem.
Louisiana suffers from those issues and more, thanks to our “reformers”. Formula changes after the school year is over (but before the letter grades are given) and calculating “Super Subgroup Bonus” points by two different methods so as to favor large, failing schools (to “close” the achievement gap) are two we have that go beyond the scope of this study. When a school is reduced to a single number or a a single letter grade, those who control the rules and formulas can create results to fit their narrative.