So is your belief that the Mucky Duck Effect has a bearing on the results and their interpretation, in the wider sense, when using EVR Dogs?
I don't follow so perhaps you would like to explain your argument slowly using plenty of small words so I don't become confused?
People who are trying to suggest that the McCanns were guilty of some offence against Madeleine need to claim that the dogs' reactions are probative evidence that a body was present in the apartment, and had contact with the clothes and the back of the car. They have misunderstood that most of the alerts were explainable by reaction to trace amounts of blood that could have come from any source, living or cadaver. This is because both Eddie and Keela alert to dried blood as per their training. Two results do suggest the possibility (not certainty) of cadaver odour- the cupboard and some clothes. An indication of cadaver odour requires a positive from Eddie and a negative from Keela.
Scent dogs are not 100% accurate. Even in this case there were reactions with no residue found which were either true reactions to minimal amounts or false alerts; se cannot know which.
Animal psychology studies show that animals are open to cueing- the Clever Hans effect. One study that used no target scent managed to get handlers to claim positive alerts only from those patches that they themselves believed to be contaminated even though all were clean
In summary to this point, dogs are a very useful indication of evidence but do not have any probative value as the law believes the science that the dogs are not infallible, in that they do make false positive and false negative alerts.
So what do people do who want to support their views that the McCanns are guilty. Well, they list case after case which hits the news where dogs were useful. No one has denied that the dogs were useful, but no one can show that the dogs are infallible.
So we have a scientific situation where Group A say "Scent Dogs are known to make errors even though they may be useful in finding evidence but they are not probative." and Group B say " But dogs have proved to be useful in all these cases. Group A say that that is very interesting, but producing further examples of utility is not helpful because it ignores failure to report the times that dogs are proved in error or uncertain.
It is called the Black Swan effect because before 1700 an example used in logic of a true statement was that 'all swans are white'. For centuries this was held to be the truth as every year more and more white swans were noted by ornithologists and logicians. Then Australia was discovered along with its black swans. One black swan added more information than a million more white swans could not.
This is the problem of 'induction'- it ignores possible future exceptions and any past ones that were not recorded.
In scientific terms it means that
If one is saying 'X is Y' is true
Arguing that every X observed has always been Y
Adding further examples of X being Y does not add to the truth of the statement.
But one example of X being not Y overturns the contention.
So listing newspaper items about successful scent dogs does not affect the truth value of "All dogs are infallible" but one case of fallibility means that what is true is that "Scent dogs are NOT infallible."
Because scent dogs including Eddie and Keela have reacted when there is no evidence found, then by logic (not belief) 'Some scent dogs are fallible' which means that "Scent dogs are not infallible."
