Minneapolis school officials had hoped that putting high school students on Metro Transit buses would boost attendance, but student absenteeism instead went up this fall.

Overall, the district went backward on attendance by an average of almost one full day per student who used a pass during the fall quarter.

There's been no analysis yet of whether the bus passes caused the increased absenteeism revealed in a report requested by the school board. "We haven't gotten deep enough into the numbers to know what the root causes are," said district official Robert Johnson.

Still, the district is concerned enough that Johnson is talking with Metro Transit about whether it's possible to discourage students from playing hooky by limiting the hours that they can use the bus passes. School Board Member Kim Ellison also asked if it might be possible for parents to opt in to limited-hours commuting for students. "There are parents out there who would prefer a much tighter limit," she said.

The district launched its Go-To pass program at Edison, Henry, North, Roosevelt, Washburn and Wellstone, with Southwest getting passes for students living outside its attendance area. The program will expand to South, the rest of Southwest and perhaps some smaller programs next year.

All students formerly eligible to ride a school bus, usually those living beyond two miles from their school, got a free pass, as did students living closer who meet income guidelines for free or reduced-price lunches.

The district said in promoting the pass program that it could prompt better attendance, in part because students could catch a later metro bus instead of missing the only school bus. The pass also allows students to stay late for after-school activities and to explore the metro area when not in school.

But data shows that compared to the same period last year, 47 percent of high schoolers had worse attendance, 30.5 percent had better attendance and 22.2 percent had no change. The data compared 2,906 pass users enrolled for fall quarter both this year and last, excluding the first week of school and students who are homeless or move frequently.

Johnson also reported that first-period tardiness is up at most schools, but added that it's also up later in the day so that's not necessarily linked to the passes.

The numbers also show that during one week last month students took 2,757 trips between 10 a.m. and 2 p.m., when school is in session. Johnson said some of those are legitimate trips by students with internships or college courses.

In his talks with Metro Transit officials, Johnson said the district also is seeking faster reports on students who use a pass when they should be in school so that principals can intervene more quickly.

District all-grades attendance has held steady at over 93 percent between 2007-08 and 2010-11, according to state data. Freshman attendance has held steady, but traditionally lower attendance among upperclassmen has risen slightly.

Steve Brandt • 612-673-4438 Twitter: @brandtstrib