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Comment by ghastmaster | Hacker News Reader

Similarly, handler beliefs affect scent detection dog outcomes to at least some degree as indicated in this study:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3078300/

> No conditions contained drug or explosive scent; any alerting response was incorrect

> Within marked conditions, handlers reported that dogs alerted more at marked locations than other locations.

> The overwhelming number of incorrect alerts identified across conditions confirms that handler beliefs affect performance. Further, the directed pattern of alerts in conditions containing a marker compared with the pattern of alerts in the condition with unmarked decoy scent suggests that human influence on handler beliefs affects alerts to a greater degree than dog influence on handler beliefs

I found this to be very telling. It at the very least warrants more study. At the worst and in my opinion, warrants elimination of dog scent detection as the sole factor in a search.

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Check out this article from the National Detector Dog Association - 'The Double-Blind Attack'. These people seriously don't believe in science.

https://nndda.org/the-double-blind-attack/

Wow!

> Results in confusion and frustration in the canine – As stated previously, under doubleblind testing, the determination of the team’s accuracy cannot be made at the time of the alert. Therefore, to provide or withhold a reward from the canine under such a condition can result in confusing and frustrating the canine, which will lead to an increase chance of incorrect responses.

Juxtapose that with the real world. I am not an expert but I sincerely doubt that K9s in airports get treats every time they correctly identify a illicit source. That is why they are trained constantly(I presume). Testing for one hour or one day will likely not have an effect on the long term ability of the dog to correctly sniff illicit sources.

The NNDDA article is addressing the "double blind attack", which in my opinion is their way of redirecting from the notion that the K9s should not be used as a gold standard to ascertain probable cause. I would have to think more on the subject to comment on reasonable suspicion. If they truly believed in the idea that handlers are benign, they would embrace the double blind process.

Reminds me of audiophiles. When the scientific method is the enemy, you are dealing with some massive psychological effects that people refuse to acknowledge.

Suppose you have a grand piano recording set up something like this https://images.squarespace-cdn.com/content/v1/59e4eb2464b05f... or like this https://i0.wp.com/royerlabs.com/photos/rec_tips/piano/Mancin...

Not only you have a multitrack recording to play with when mixing/mastering, but the tracks are naturally frequency weighted due to spatial positioning. Mix these tracks into stereo with some panning and play it on a decent set up with large-ish (say 5m) scene. You end up with unnaturally large grand piano spanning the whole scene. It does not sound "natural", but gives fake perception of "scene".

The whole audio field is weird constant chase between production, recording and reproduction (e.g. in the 90s V shaped frequency profile used to be quite prevalent to sound good on boomboxes) which gives perfect breeding grounds for audiophilic mysticism. No set up will ever be able to "naturally reproduce" both rock concert and chamber orchestra.

I have noticed that there are two types of audiophiles. The first kind has certain collection of records and strive for a set up that gives them the same goosebumps they felt first time hearing the recording/concert, the second kind lives off giving goosebumps to their audiophile friends bringing their own records. Both live in constant grind for perfection that they will never achieve.

> I sincerely doubt that K9s in airports get treats every time they correctly identify a illicit source.

Why do you doubt that? When people say "treat" they don't mean a full day at the spa. It's a bite of something tasty, or a bit of play with a tennis ball while the dog handler says "goood booooooy".

they absolutely treat the dog for finding contraband. that’s how you train them to alert on the smell. the problem is that this means they might alert for nothing at all, just because they want a treat

Wow. Everything in that article reads as an admission that canine units are utterly useless, even as the article tries to defend their use. The primary argument seems to be that dogs need constant and immediate reinforcement in order to be effective, and therefore double-blind studies are not effective measurements. This same argument would also imply that canine units are not effective in the field, since the handler wouldn't be able to provide accurate reinforcement.

If that would be treated seriously, it would mean that detector dogs are impossible to use in case where they need to find or detect something.

So they are completely useless.

Is nndda.org actually serious representation of them?

Oh, they're extremely useful, just not for the thing you think. They manufacture cause for searches. It's a form of evidence laundering.

And yes, the NNDDA is one of several organizations that certifies police dogs.

A bit similar in the story of the counting horse from Germany in the early 20th century: https://en.m.wikipedia.org/wiki/Clever_Hans

My wife had tulip bulbs from Amsterdam in her carryon and the beagle at customs immediately identified her. It was amazing.

That said I’m sure even without training them to do so they look to their handlers for cues.

I know guys who smoked a lot of pot when they were younger. Would even fly with a small stash.

Never got caught or had a dog alert on them. They also didn't look like stoners. Whatever your stereotype is of how a stoner looks (and there are a few).

The 9/11 attackers were all clean shaven and dressed in business casual.

While I've seen roaming dogs in airports this was in customs and she passed by everyone. I'd certainly tell those friends to not try that on an international flight judging by that experience.

My one friend came from an English family so mostly flew to the UK.

As I understand it, buying drugs there is not a problem. No need to fly with them.

> immediately identified her.

How many others were "immediately identified" but were not carrying bulbs?

0. The handler even immediately asked if we had tulip bulbs - though I'm guessing that was just because she knew where we came from.

Was she aware of the bulbs being a potential issue? Maybe she sweated or showed other signs.

I don't think she was nervous about it as we got them in the airport, though she was confused as to whether or not we needed to declare them.

At this point, I'm convinced sniffer dogs are the dowsing rods of our time: basically just serving as psychological salve to reinforce a feeling of safety.

Are you saying the "use" of sniffer dogs, or that sniffer dogs are unable to accurately determine individual scents ?

The use of sniffer dogs in schools and airports.

I can tell you the drug sniffing dogs in use in Queensland, Australia in the late 2000s absolutely were basically “dowsing rods” (I was involved in illicit things at the time and went past/was sniffed by drug dogs over a dozen times and was never caught or searched despite having illegal drugs on my person, without much of an attempt to hide them). I’ve shown my partner how the handlers give a signal to the dogs to “mark” someone for a “probable cause” search too.

I had a cop friend directly tell me that there is no point to telling an officer not to search your car. If he feels like it, he will call a K9 unit, and the with that he will have probable cause to search the car. I said what if the dog doesn't detect anything. He laughed and said that doesn't happen.

There is a point. I understand your friends point though. In the USA, not giving them permission allows your lawyer to fight the case on the ground that it was an illegal detention. Case law has set precedent that without reasonable suspicion officers cannot extend your detention in a traffic stop just to bring a dog in(Rodriguez v united states 2015). Never ever give permission to search.

I know he's your friend, but "don't take legal advice from your opponent" applies here. It may be true that they will inevitably find a reason to search your car. It may not be true that the ensuing search will be legal and hold up in court.

Of course, there is a nonzero chance you will not survive to see a court date, but that's a different policing issue.

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