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Handler beliefs affect scent detection dog outcomes (2011)

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Re: Handler beliefs affect scent detection dog outcomes (2011)

#31

Post by bayesian_horse »

jaclaz wrote: post #26
lultimouomo wrote: post #15

Earlier quoted context omitted.

> 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". 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.

Sure, I know about that. It is part of the (IMHO completely off) ways the Law is applied in the US, I don't think that the same exists (or is used to the same extent) in other countries. 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/...

Intent on the part of the handler is optional, I think.

Common Biases on top of good intentions would be enough to produce the "desired" false positives.

Re: Handler beliefs affect scent detection dog outcomes (2011)

#32

Post by pulisse »

bayesian_horse wrote: post #8
jaclaz wrote: post #7

The observation seems logical, but I wonder what is actually the relevance of the study in practice. 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…

I have heard the term "search warrant on four legs". 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.

> In many jurisdictions, including the US, police officers are not allowed to search anybody or their cars, even if they are black.

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.

Re: Handler beliefs affect scent detection dog outcomes (2011)

#33

Post by your-nanny »

truths33k3r wrote: post #12

how is this nonsense even getting published? tiny sample size, n=18 dogs 5 different breeds of dogs large variance of dog age

if the dogs were restricted to male Labradors age 5, then the range of inference would be male Labs age 5.

Re: Handler beliefs affect scent detection dog outcomes (2011)

#34

Post by BlackFly »

truths33k3r wrote: post #12

how is this nonsense even getting published? tiny sample size, n=18 dogs 5 different breeds of dogs large variance of dog age

This shouldn't surprise you, but if the effect is large and real, you don't need large sample sizes to prove something. As an example, a loaded die that always comes up with 6. After 18 straight 6's in a row, you are more than assured that you have a loaded die. I imagine that a rational person is convinced long before the 18th 6.

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.

Re: Handler beliefs affect scent detection dog outcomes (2011)

#35

Post by praptak »

jaclaz wrote: post #7

The observation seems logical, but I wonder what is actually the relevance of the study in practice. 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…

4) Fabricating a probable cause for a search when there is none: news.ycombinator.com/item?id=10942196

Re: Handler beliefs affect scent detection dog outcomes (2011)

#37

Post by tanepiper »

I've been doing detection classes with our Polish Hunting Spaniel and she's quite the natural, but the hardest part of it is training the human (i.e. me) to NOT give off any queues about where I think things may be.

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.

Re: Handler beliefs affect scent detection dog outcomes (2011)

#38

Post by edoo »

seanwilson wrote: post #17

Is this not fairly well understood? e.g. 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…

It should be easy to train the dogs in an environment where the trainer does not know the intended result and must investigate each claim from the dog. All the dog training vids I've seen have the trainer themselves knowing exactly what lies in the course.

Re: Handler beliefs affect scent detection dog outcomes (2011)

#39

Post by silveroriole »

edoo wrote: post #38
seanwilson wrote: post #17

Is this not fairly well understood? e.g. 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…

It should be easy to train the dogs in an environment where the trainer does not know the intended result and must investigate each claim from the dog. All the dog training vids I've seen have the trainer themselves knowing exactly what lies in the course.

I don’t think this would be easy. For training, the reward needs to come as quickly after/during the action as possible. Most dogs don’t have a great mental capacity for figuring out that they’re being rewarded for something that isn’t happening right now. If the dog has to wait even 10 seconds for the trainer to figure out whether to reward or not, a lot of dogs are going to get confused.

Re: Handler beliefs affect scent detection dog outcomes (2011)

#40

Post by logfromblammo »

silveroriole wrote: post #39
edoo wrote: post #38

Earlier quoted context omitted.

It should be easy to train the dogs in an environment where the trainer does not know the intended result and must investigate each claim from the dog. All the dog training vids I've seen have the trainer themselves knowing exactly what lies in the course.

I don’t think this would be easy. For training, the reward needs to come as quickly after/during the action as possible. Most dogs don’t have a great mental capacity for figuring out that they’re being rewarded for something that isn’t happening right now. If the dog has to wait even 10 seconds for the trainer to figure out whether to reward or not, a lot of dogs are going to get confused.

During training/testing a second person, who is not visible, audible, or smellable to the dog, and who knows the conditions of the course, observes the pair via cameras and microphones.

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.

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