Handler beliefs affect scent detection dog outcomes (2011)
link.springer.com
link.springer.com
That said, dogs can be fantastic when used for finding threats rather than 'proving' what the handler already believes. They have a combination of nose and brain that we can't replicate any other way and are great for search and rescue, finding explosives and some law enforcement searching.
[1] https://headspace-the-book.blogspot.com/2008/07/acpo-police-...
Basically, this kind of comment usually encodes some belief on what the law should be rather than a belief about how it should be enforced. And that's just not the issue at hand here.
One of the most common criticisms of airport security in the US is that the harm it is preventing is nowhere near commensurate with the burden it imposes on the populace. That may or may not be true, but it's not a belief about what the law should be, it's a belief that at some point, the price paid for additional safety is too high.
Likewise with children, as a father of 4, I also understand the desire to go to any lengths to keep our children safe, but keeping them in a bubble for their entire lives, while certainly protecting them from many tangible harms, will ultimately stunt their growth. Once again, the price paid for safety can be too high.
I happen to think that drug sniffing dogs are on the wrong side of the line. They probably do alert the police to drugs that would not have been found otherwise, but in my opinion, they allow the police to have far too much latitude when it comes to searches.
Maybe he wouldn't, but I would be. In the land where witch hunts are illegal, I'm one of the three civic minded Libertarians.
Civil rights revocation should never be treated lightly. Period. Pragmatism must take the backseat to ideals in this regard, lest we end up undoing the very thing we're trying to protect in the first place.
As much as that tends to put me at odds with my own pragmatic side, I can't argue with the direction things tend to take when we cave to the urge to sacrifice liberty for safety.
https://en.wikipedia.org/wiki/Clever_Hans
> Clever Hans (in German: der Kluge Hans) was an Orlov Trotter horse that was claimed to have performed arithmetic and other intellectual tasks.
> After a formal investigation in 1907, psychologist Oskar Pfungst demonstrated that the horse was not actually performing these mental tasks, but was watching the reactions of his trainer. He discovered this artifact in the research methodology, wherein the horse was responding directly to involuntary cues in the body language of the human trainer, who had the faculties to solve each problem. The trainer was entirely unaware that he was providing such cues.
I think it's a worthwhile study, especially considering such dogs are currently still used in law enforcement. It's important to be aware of the shortcomings and biases of this methodology, and to do so in a sound, scientific manner.
When the dog hits on something, the observer presses a button, indicating which target or decoy was indicated, or that an unexpected other object was indicated. The observer may also indicate when the dog seems distracted, or especially attentive to the handler.
A computer takes the buttons as inputs, and if its intermittent reinforcement program indicates it, the handler receives an instruction to reward the dog. The program may also reward the dog for misses, or just for paying attention to handler instructions, so the handler is not able to associate rewards with accurate hits. The handler then still has to investigate the hit to determine what the dog found.
The first is you'd probably have to get someone else to hide the scent for you. Not so easy when training solo.
The second is that when you want to reinforce a behaviour you generally give a trigger or marker as soon as possible after the event. If you wait too long, the dog may associate the marker with another behaviour they've done in the meantime and overwrite the correct learning. So a 'yes' or clicker as soon as the dog alerts is the best way to go. But if you yourself don't know where it is, you risk reinforcing a failure. This is easy with a helper so you can glance at them and they indicate if you are correct or not.
Also, I vaguely remember a high-profile case where the evidence was dismissed precisely because the procedures for gathering and testing the samples were not followed.
Are you fine with black communities being ruined by crack cocaine because police can't search people? Of course not, that'd be a ridiculous thing to think.
Being physically searched by men with guns is not something innocent people should be subjected to with no, or just the thinnest of illusion of justification.
It turned out the test weren't done 'blind' and the practice has been abolished.
I don't know how good dogs are at pose detection, but it's definitely plausible that they can tell when an alert is expected.
It's less about the handler's pheromones and more about movement, speech and posture.
Dogs can however distinguish behavior patterns in their handlers, because that's mainly how they get rewards and are punished.
Both the patterns and the rewards are much more subtle than handlers are generally aware of. A service dog is in some sense the worst case of an overfitting machine learning model you can imagine.
Of course, these are fun classes and in no way controlled environments - but the best thing you can do is to trust the dog's judgement.
tiny sample size, n=18 dogs 5 different breeds of dogs large variance of dog age
The point is: large samples are only needed to measure small effects. Most studies nowadays need large samples because the large effects are low hanging fruit and were noticed quickly (in the past). Meanwhile, finding a single black swan proves that not all swans are white.
This study proves that in even a small selection of scent dogs, you are going to have dogs which are highly affected by handler signals. You might be able to use the methods of the paper to exclude dogs which pick up on handler signals and therefore improve the training regimen of scent dogs, there is no evidence to support this possibility however.
To a small degree I can agree to this. But I have k9 officer friends and I know their dogs. Good luck with this. It means a bad and impatient handler rather than an ineffective dog. But it's alright, police baaaaad. Evidence is evil.
I mean, there are three common situations where these dogs are used:
1) airports, stations, traffic stops etc. where the influence of the trainer might be relevant (i.e. the trainer, even if involuntarily, may influence the dog if the person that is sniffed - or their belongings/looks/behaviours/etc. - look suspicuous to the trainer)
2) search in buildings for drugs or explosives
3) screening of mail, packages, containers, etc.
I believe that among these only in activity #1 the trainer might have some pre-constituted suspect that would "trigger" the influence on the dog.
But in any case the dogs are only used as a means of "triage" of sorts, so at the most this influence leading to false positives will cause some time wasted.
Still in case #1 (and possibly in case #3) the issue might be that if there are too many of these false positives, while the attention of the trainers/policemen is drawn to the "false target" some other one (actually carrying drugs or explosives) will "go through".
In many jurisdictions, including the US, police officers are not allowed to search anybody or their cars, even if they are black.
So if the dog learns to please his handler by indicating contraband, they have a chance to at best inconvenience anyone they (dis)like.
Sure, but (of course it depends on countries and local Laws) it is only one of the possible ways (excuses) that can be used to target someone.
Of course if in the car there is no drugs (or explosives) the only net result is a waste of time of both the policemen and the "target".
It would seem to me much more relevant to know how many cars searched after a dog sniffed something ended up as being actually contraband free (false positives) and how many actually turned out as actually containing some drugs or whatever.
If the dogs (in experiments without the influence of the trainer) have an accuracy of - say - 90% and with the influence of the trainer (or whatever other reason causes on field differences) this drops to - still say - 55% then there will be an issue as we would be nearing the flipism convenience, but if the overall accuracy remains in the 80 or 85% range then the effect - even if noticeable - would be not much relevant in practice.
Or, if you prefer, I completely agree that a trainer can induce a dog to sniff something even when there isn't any, but the relevance of the fact depends only on how often this happens.
Google for "civil forfeiture dog car stop". They don't need to find drugs to take the car or any cash in it, as the dog signalling is deemed enough of a cause for forfeiting, though not for prosecuting criminally.
But the base issue is still about reliability of the dog, the integrity of the trainer handler and how it is considered "acceptable" see:
https://www.washingtonpost.com/news/the-watch/wp/2015/08/04/...
Common Biases on top of good intentions would be enough to produce the "desired" false positives.
Sadly, I don't think the false positive alert rate is something the police are looking at or trying to reduce. In my cynical opinion, they are just looking for more reasons to find you a criminal, even if you aren't one. If they view you as a criminal to start, that's a huge burden to overcome.
Perfectly honest or understandable motivations and beliefs are sufficient.
Exactly.
In many US jurisdictions it is settled case law that a search is justified if an officer simply avers that they detect the smell of marijuana, with no other cause or corroboration required.
Handler bearing absolutely plays a role if you aren't careful. One way our trainer taught us to fix this was to try to pull the dog away from the scent during training. If he follows us, we leave the room and stop the activity. The idea is to tell him that humans are stupid, they don't know where the scents are, so stop trusting them, because then your game and reward goes away. It worked very quickly and now he locks his legs and won't move when he's got the odour. This avoids accidentally pulling him off the odour when you're covering a large area at a brisk pace.
Regardless, whenever possible one of us hides the odour and the other runs the dog. This helps us avoid any preconceptions (such as focusing on one corner of the room, missing potentional scent cones from cross-drafts). Humans can still mislead the dog like this so it's best to form good habits and have an open mind.
That "time wasted" feels more like a psychological torture or at least a day ruined, and you ignore that cops stop mostly the same people every time, so sometimes it's a day ruined every day.