Oak National Academy has come under fire for failing to fix a "disgraceful" captioning error in one of its Year 1 lessons, which involved the word "pirates" being mistakenly transcribed as "perverts".
Marcia Goodwin, a former headteacher, told Tes that the error posed a "safeguarding issue", both because the word itself was "not appropriate" for children and because the incident raised questions about the reliability of the site's "quality assurance process".
The lesson, which teaches children to "generate ideas for a created story", features a tale about a pirate named Tom, whose treasure map is stolen.
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The teacher delivering the lesson says: "So the setback for me is that there's lots of pirates that steal his treasure map and Tom is all on his own."
But the closed captions state: "So the setback for me is that there's lots of perverts that steal his treasure map and Tom is all on his own."
Ms Goodwin said she raised the issue with Oak shortly after 1pm on Monday.
However, Tes found that the issue had still not been fixed by 6pm this evening.
Oak told Tes that it was "very sorry for this unfortunate error" and would correct the mistake as soon as a current update to its site was completed "in the coming days".
Oak National Academy apologises for 'unfortunate error'
Ms Goodwin said: "I was just reading the lesson to prepare because my son and daughter-in-law are working parents – I do a little bit of prep for them before they have to do the online lesson with their daughter and...the word was there, it was immediate.
"So nobody has looked at that lesson, nobody's looked at that lesson, because you would see that it says 'perverts'.
"It's disgraceful because...I mean the word itself becomes a safeguarding issue, but it could have been a swear word, it could have been anything. If nobody is quality-assuring that, you know, what is going out to anybody?
"It isn't just schools that can be using that, home school people could be using it, anybody could be using it. Where is the quality assurance process? Who's checking it?"
She added: "It's not appropriate for Year 1, it's not appropriate for any children, but an able-reading Year 1 could read that word and then that raises the question with mum: 'What does perverts mean? Why does it say perverts?' I mean, it goes on and on.
"I understand how it's happened – it's a computer-generated voice, you know, translator. I get all of that and I don't expect them to have somebody there typing up what the teacher is saying. But somebody should be checking it. It's going to children."
Matt Hood, principal of Oak National Academy, said: "Oak National Academy has nearly 10,000 lessons available, with well over 200,000 minutes of video and therefore millions of words, each of which is transcribed by people to ensure those with hearing impairments can access the site on the same terms as their peers.
"We're grateful a user has flagged this typo that has crept in and we're very sorry for this unfortunate error. We're currently updating the site to launch around 500 new lessons so that we can keep supporting our 1 million pupils a day. We'll correct this error as soon as this is complete in the coming days."