In a clear message to the leader of a district struggling and under pressure to boost achievement, the Minneapolis school board gave Superintendent Bernadeia Johnson her lowest performance bonus to date Tuesday night.

In its evaluation, the board found that Johnson had improved the district's finances and nutrition, but said bluntly "we are frustrated with the incremental rate of academic growth." It said it wants more diverse teachers, a better principal corps and closer involvement of families in the district's work.

The board granted Johnson $7,452 for hitting performance goals over the last year. It has consistently proven a tough grader, awarding her slightly more than $12,000 in each of the past two years. The previous maximum possible bonus for Johnson was $30,000 atop her $190,000 annual salary; that rose to $40,000 in her new three-year contract that kicked in last July.

The board's review took into account a report that Johnson's administration presented to board members Tuesday night, citing dismal academic progress in which the district failed to hit all but three of its targets for improvement.

"I am just as frustrated as you are with the rate of progress overall," she responded in a prepared statement. But she said she remained confident in her strategies. "There are no simple answers or shortcuts to the sustainable high performance that must be our goal."

The state of city schools, from which a bare majority of students graduate after four years of high school, was one of the top issues in this fall's mayoral campaign, vaulted by a poll that found education was residents' highest priority.

Johnson said the district needs more flexibility to direct teaching talent and money to where they're needed, a clear nod to proposals on the bargaining table with teachers. The board is also in the early stages of considering whether it will revamp its budgeting to take into account the salaries of teachers and other factors that affect how money is spent.

Johnson said when the new contract was announced that, "Minneapolis public schools must be a workplace that is results-driven. We still have much progress to make."

There's been consistent improvement in the reading readiness of kindergartners, for example, the four-year graduation rate inched up, and the district has made some progress in reducing its third grade math and reading gaps. But narrowing the achievement gap between white and minority students has been elusive.

A majority of the board faces election next year. All but one member has turned over since Johnson was hired as superintendent in 2010 without interviewing others. But all but one of the current board members was on the board that granted her a new three-year contract in 2012.

Johnson said she'll respond to the poor academic report card with a more focused strategy on kindergarten through third-grade students to minimize the early learning gap, including dual teachers at a small number of targeted schools. She said she's firmly behind initiatives to evaluate teachers and impose an instructional protocol that tries to keep teachers on a similar curriculum. She said the district will enforce what it views as best practices for improving learning, focus her associate superintendents more on academic improvement, do more to help high schoolers regain lost credits, find alternatives to suspension, and consider year-round school for lagging students.

Steve Brandt • 612-673-4438

Twitter: @brandtstrib