The problem with false positives

One of the objections raised to the regular monitoring of tens of thousands of home educated children is that large scale operations of this sort are bound to generate many false positives. What are false positives? Really, they are no more than mistakes; thinking that something exists or is happening when it is not. This expression is more commonly used in medicine and the consequences there can be horrific. Suppose that I am screening ten thousand women for breast cancer and I have a rate of false positives of around 1%. This would mean that a hundred women would be wrongly diagnosed with cancer. In a worst case scenario, this could lead to their having unnecessary mastectomies.

Another field where false positives could have terrible results is in the investigation of child abuse. If I look at hundreds of children using a discredited method like the anal dilation test, then I will be claiming that I have found evidence of sexual abuse in children where none exists. The consequence here might be for children to be removed from their families.

There is always a risk of false positives with mass screening and the larger the programme; the more likely are we to generate false positives. If we look at forty thousand home educated children, it is a racing certainty that we shall wrongly decide that a fair few of them are not receiving an efficient, fulltime education. This has been put forward as a good reason to avoid the routine monitoring of home education in this country.

The question which we need to ask about this idea is this; would it matter? In other words, if this mass screening resulted in local authority officers wrongly deciding that some of the children whom they saw were not being educated efficiently, what would happen? We saw earlier that in medicine, the result might be a breast or lung being removed unnecessarily, but what would happen in this case? What do local authority officers do if they find a home educated child whom they think is not being properly educated? The answer is of course, that they generally do nothing at all. The issuing of School Attendance Orders to the parents of home educated children is as rare as hen's teeth. Many local authorities never issue them and those that do might manage one or two in a typical year. The worst thing that a parent whose child has been wrongly diagnosed as being uneducated will have to endure is the disapproval of some minor apparatchik from the town hall. This is hardly a disaster!

I keep an eye out for cases of home educated children being forced to attend school and if it were happening, then I think that we would know about it. We know that some local authorities believe that they have a substantial number of children in their district who are not receiving an education, this at least as what they told Graham Badman. They do not however do anything about it.

I do not think that the danger of false positives is a good reason for avoiding the regular monitoring of children who are being educated at home. The consequences are usually non-existent and so I think that we can leave this particular worry out of the equation. I am sure that if every child were to be visited in her home, that some fairly shocking cases would be unearthed, which are currently hidden from view, but for the vast majority of families, it would be business as usual. The obvious question then is this. If there will be no practical consequences when a child is found to be inadequately educated, what is the point of conducting such mass screening in the first place? For one thing, parents may not in general know that there is little chance of legal action. It may be possible to bluff them into action merely by making empty threats. this would be a good thing for their children's education. Another point is that parents currently know that they can take their kids from school and avoid the local authority; refusing even a visit in many areas. if this were no longer possible, it might make them think twice about taking their child out in the first place. Regular monitoring visits of this sort might go some way towards abolishing what Graham Badman called 'home education by default', where parents de-register a child simply because they see no other option.