Have the dog alerts any significance?

[Alice Purjorick]

TRIALS BEGUN: January 1997
NUMBER OF DOGS USED: Five different dogs
POST-MORTEM INTERVAL RANGE: From 70 minutes to 3 days
NUMBER OF TRIALS COMPLETED: As of July 1997, total of 52 trials completed
PRELIMINARY RESULTS: The shortest post-mortem interval for which we received a correct response was one hour and 25 minutes. However, the post-mortem interval for which we received a consistently correct response from all dogs involved is 2.5 - 3 hours.

NOTES:
We emphasize our inability to control all variables during our project. It has been impossible for us to obtain scent samples and carry out the trials under strictly controlled conditions. We had no control over the environmental conditions under which our samples were gathered, manner and cause of death, nor could we exercise tight regulation over the quantity of samples of any one given time interval. Since there are periods in which our samples are few and far between, this project has no set deadline and will be ongoing for a time. Our intention is not to offer an absolute answer to the questions posed, but to initiate an ongoing dialogue and offer what we hope is a point of departure for other exciting research projects. This will shed light on the under-navigated and sometimes mysterious arena of canine olfaction applied to body recovery.

It is important to note what the dogs are not being asked to do, as well as what they are being asked to do. They are not choosing from a lineup of actual human tissue, but only from gauze pads for which great care has been taken to expose them only to dry skin regions, not to any blood or perceivable body fluids. Also note that the exposure time is exactly 20 minutes.

[Mr Gray]

There is no evidence that remnant scent would still be present 3 months after any death and simple physics would make this unlikely. As to the alert outside in the flower bed there is no evidence remnant scent would last outside for 3 months

[Lace]

Found this -   http://www.cbc.ca/news/technology/cadaver-dogs-science-training-1.3654993

Read the part titled 'PIG PROBLEM'   according to this woman,  she did an experiment using chicken,  pig and cow with cadaver dogs and she said the pig was the one that smelt least like human,  she said which is a problem for cadaver dog trainers in the UK,  she says if they are trained on pig then they will search for pig.   Yet Grime said they couldn't tell the difference between pig and human remains,  very confusing.

Also this bit -  If handlers weren't using blind testing (where the handler doesn't know the location of the target scent) or double blind testing (where both the handler and test adjudicator don't know the target) then the dogs could simply be picking up on unconscious cues from the handler, not the scent itself.

Mmmm

You know what I'm wondering if these cadaver dogs in the UK just go by the smell of decomposing  blood.

[ferryman]

Found this -   http://www.cbc.ca/news/technology/cadaver-dogs-science-training-1.3654993

Read the part titled 'PIG PROBLEM'   according to this woman,  she did an experiment using chicken,  pig and cow with cadaver dogs and she said the pig was the one that smelt least like human,  she said which is a problem for cadaver dog trainers in the UK,  she says if they are trained on pig then they will search for pig.   Yet Grime said they couldn't tell the difference between pig and human remains,  very confusing.

Also this bit -  If handlers weren't using blind testing (where the handler doesn't know the location of the target scent) or double blind testing (where both the handler and test adjudicator don't know the target) then the dogs could simply be picking up on unconscious cues from the handler, not the scent itself.

Mmmm

You know what I'm wondering if these cadaver dogs in the UK just go by the smell of decomposing  blood.

From the article Lace links to above:

She conducted a study on the compounds of human decomposition compared to those of cows, pigs and chickens.

The smell of decomposing pigs was least similar to that of humans, which is a problem for cadaver dog trainers in the U.K., where it's illegal to possess human remains.

[Lace]

From another article in America -   

I’ll be honest: if this book were simply one woman’s transformative relationship with her working dog, I probably wouldn’t be covering it. As interesting and valuable as that story is, this blog needs that next layer — the whys and hows behind dogs and the dog-human relationship. How does a dog start as a dog with a nose and become a dog who uses his nose to stop beside a corpse under a canopy of trees in the woods? How do dogs learn that dead squirrels and rotting trees are not the end goal and should be ignored? Warren explains that researchers are slowly learning about the volatile organic compounds released from human remains. Additionally, while “…we humans smell much more like chicken than pig when we decompose,” cadaver detection dogs should only be trained on human remains. (To that I am obliged to add, ‘One day you will smell (somewhat) like a dead chicken’).

[Mr Gray]

So no scientific studies produces tha support the alerts because there aren't any
As I said previously

[stephen25000]

'The Search for a Volatile Human Specific Marker in the Decomposition Process'

http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0137341

[Mr Gray]

'The Search for a Volatile Human Specific Marker in the Decomposition Process'

http://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0137341

That article has absolutely nothing to do with the reliability of the alerts
Try again

[stephen25000]

Well, there is some more to add.................

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0146963#sec020

From the discussion:

"The present study showed that our rigorous training procedure leads to a very high level of identification in human odour matching-to-sample tasks, with dogs alerting to target odours in 85 ± 4% of cases and never alerting to non-target human odours (100% specificity). According to Jezierski et al. (2014, [36]), high detection scores should be regarded as exceptional and indeed dubious as they depend on a variety of factors such as odour presentation method, odour source and, of course, individual differences in dogs’ olfactory detection thresholds. The present data confirm this attitude, inasmuch as sensitivity was critically dependent on the type of odour presentation during the task and specificity dependent on the dog’s breeding (FAs made exclusively by Belgian Shepherds)."


...............................

'This one specifically looks at cadaver dog performance. You might have to go to a different site to read the full text'

http://www.fsijournal.org/article/S0379-0738(14)00352-1/abstract

[Mr Gray]

Well, there is some more to add.................

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0146963#sec020

From the discussion:

"The present study showed that our rigorous training procedure leads to a very high level of identification in human odour matching-to-sample tasks, with dogs alerting to target odours in 85 ± 4% of cases and never alerting to non-target human odours (100% specificity). According to Jezierski et al. (2014, [36]), high detection scores should be regarded as exceptional and indeed dubious as they depend on a variety of factors such as odour presentation method, odour source and, of course, individual differences in dogs’ olfactory detection thresholds. The present data confirm this attitude, inasmuch as sensitivity was critically dependent on the type of odour presentation during the task and specificity dependent on the dog’s breeding (FAs made exclusively by Belgian Shepherds)."

what it says is taht dogs recognise cadaver odour...we know that

what it doesnt tell us is how reliable an alert is....can you not see that

read what it says in red

[stephen25000]

what it says is taht dogs recognise cadaver odour...we know that

what it doesnt tell us is how reliable an alert is....can you not see that

read what it says in red

Where is it discounted ?

Eddie and Keela were extremely reliable.

Martin Grime did his job, with no axe to grind.

[ShiningInLuz]

That article has absolutely nothing to do with the reliability of the alerts
Try again

From the article.  "These markers would allow a more efficiently training of cadaver dogs or portable detection devices could be developed."

Your contention that the process of cadaver decomposition had not been studied is totally inaccurate.

Further, that article is stuffed with references to previous studies.

The idea that cadaver decomposition and dog capability has not been scientifically studied is unfounded.

The scientists have been trying to work out what goes on in a doggie nose and how to improve it in study after study ... after study .... etc.

[Mr Gray]

From the article.  "These markers would allow a more efficiently training of cadaver dogs or portable detection devices could be developed."

Your contention that the process of cadaver decomposition had not been studied is totally inaccurate.

Further, that article is stuffed with references to previous studies.

The idea that cadaver decomposition and dog capability has not been scientifically studied is unfounded.

The scientists have been trying to work out what goes on in a doggie nose and how to improve it in study after study ... after study .... etc.

you need to look back at the post at what I said
I said theere are no studies to support the alerts and there are not. There has been no scientific study of how accurtae the alerts are.

[Mr Gray]

There are almost no scientific studies to support the alerts
If there were these could be cited in court and used in evidence
They do not exist


so where are the studies which support the alerts...where are the studies that show how accurate  they are

[Mr Gray]

Where is it discounted ?

Eddie and Keela were extremely reliable.

Martin Grime did his job, with no axe to grind.

where is the evidence that these two dogs are reliable...there is no independent evidence