When the chief technology officer for Montgomery County schools gave a talk at a conference in Missouri a few years ago, he used a PowerPoint presentation that mistakenly included the names and photos of 16 Bethesda kindergartners, along with phone numbers.

It also listed the names, student identification numbers and reading scores of 145 Germantown fourth-graders.

The confidential student information got another audience at a conference in Alabama and was uploaded on a federal government Web site. The presentation was quickly removed after a parent alerted school system officials that it was online in March.

The inadvertent publication of the sensitive data has left some parents questioning how such information could be mishandled and what safeguards are in place to prevent it from happening again.

Montgomery school leaders say it was a one-time misstep that was corrected. They say they vigorously protect student information and do a good job at it — and that there is no systemic problem.

“Student data is guarded extremely tightly, and this was a mistake,” said schools spokesman Dana Tofig.

Many parents say they first heard about the problem when the school system’s chief technology officer, Sherwin Collette, wrote a letter this spring apologizing for the leak. He wrote that the 2011 PowerPoint was “not redacted consistent with our practices.” Last week, he spoke at Matsunaga Elementary, where the reading scores of fourth-graders were compromised.

“I take responsibility,” Collette told parents, apologizing again. He said he didn’t realize that the information came from actual students. “The assumption was it wasn’t real data,” he said.

Several parents said afterward that they wanted to know more about written guidelines for the use of student information, employee training and consequences for improper releases.

Olga Ney, whose son was among the then-fourth graders, said she would like to see school officials follow up with families about efforts made to ensure better protection of student data.

“I heard a lot of good intentions, but I want to see actions,” she said.

The PowerPoint presentation focused on measurement analysis and knowledge assessment. In one slide, 16 photos of kindergartners at Wood Acres Elementary in Bethesda were displayed beside names and phone numbers.

In another slide, names of fourth-grade students at Matsunaga were arrayed with their reading scores. Among those identified was the daughter of Montgomery County Council member Craig Rice (D-Upcounty). Rice said he learned about the problem in late March, when a neighbor called him to let him know she found the presentation online.

Rice said he is not certain how the error was made but considers it “a genuine mistake” and has been assured that it won’t occur again. “This is something that shouldn’t have happened,” he said.

Collette, through schools officials, declined a request for an interview.

In Collette’s letter, he said he was not aware that the organization supporting the conferences uploaded the presentation to a National Institute of Standards and Technology Web site. When he found out, he said, he worked with NIST to get it taken down.

Susan Mordan, a Wood Acres parent whose son was among the students pictured, said she was disappointed that once the slide was presented at the conference, “no one gasped and said, ‘That shouldn’t be up there.’ ”

“My concern is that people who were in charge of making a good decision on behalf of my child didn’t make a good decision,” she said.

Amanda Graver, a Montgomery parent and longtime education advocate, said she believes that more accountability is needed. “I feel like it’s a big deal, and MCPS isn’t taking it like it’s a big deal,” she said. “They seem to be annoyed with parents for being concerned.”