are the best indication of teaching ability (295 2 at 14). But plaintiffs' expert on the labor market for teachers, Dr. Hamilton Lankford, testified authoritatively regarding other factors that are probative of teacher quality, and several experienced administrators testified that principals' reviews tend to conceal teacher inadequacy because principals find it difficult to fire bad teachers and to hire better ones. In our view, the Appellate Division improperly narrowed the inquiry here. Considering all of the factors, we agree with the trial court's findings and its conclusion that the teaching is inadequate. The 1999 655 Report noted that schools with the highest percentages of minority children "have the least experienced teachers, the most uncertified teachers, the lowest-salaried teachers, and the highest rates of teacher turnover." The same report showed that well over half of the State's minority children attended New York City schools; that 84 percent of New York City schoolchildren were minorities; and that most of these children are poor. Taken together, these and other facts and statements in the 655 Report amount to an admission by the State agencies responsible for education that -- with respect to teacher experience and retention, certification and pay -- New York City schools are inferior to those of the rest of the State. To be sure, the Education Article guarantees not equality but only a sound basic education ( see Levittown, 57 NY2d at 48). But as Judge Levine observed in his concurrence in CFE, "the constitutional history of the Education Article shows that the objective was to 'make[] it imperative on the State to provide adequate free common schools for the education of all the children of the State' and that the new provision would have an impact upon 'places in the State of New York where the common schools are not adequate'" (86 2 at 327 [Levine, J., concurring, citing 3 Revised Record of Constitutional Convention of 1894, at 695] [emphasis added]). The 655 Report indicates a mismatch between student need in New York City and the quality of the teaching directed to that need, and it is one authoritative source of facts showing the extent of the mismatch. The report, for instance, shows that in 1997 17 percent of New York City public schoolteachers either were uncertified or taught in areas other than those in which they were certified. The trial court noted this fact and evidence that uncertified and inexperienced teachers tend to be concentrated in the lowest performing schools. Notably, Dr. Lankford demonstrated not only that New York City schools had the largest percentage of teachers with two or fewer years' experience but also that this percentage was greatest -- at 17.9 percent -- in the