EHD swabs and "false" detections
#46
Join Date: Apr 2009
Posts: 2,195
Originally you said:
(my emphasis)
I asked you to provide data to back up the assertion that ETD systems are particularly good at identifying "something dangerous".
You did not provide data, instead, you changed your tune significantly and now say:
I'm glad you recognized your mistake.
(my emphasis)
I asked you to provide data to back up the assertion that ETD systems are particularly good at identifying "something dangerous".
You did not provide data, instead, you changed your tune significantly and now say:
I'm glad you recognized your mistake.
Splitting hairs serves no useful purpose, and neither makes the other right or wrong, it just makes the conversation inane when one party pretends obtuseness.
It is really sad that you can't admit that the TSA ETD machines often alert on items that are not dangerous. By any measure that is a false positive. Even worse is TSA inflicting these terroristic screenings on people who have done absolutely nothing to merit an item by item inspection of their belongings.
And you call me obtuse.
And you call me obtuse.
Once again, for those in the cheap seats: ETD systems alarm when a chemical is detected that warrants further investigation by the screening TSO. That does not make the alarm a “false alarm”, it makes it an alarm. One that must be investigated further.
Originally you said:
(my emphasis)
I asked you to provide data to back up the assertion that ETD systems are particularly good at identifying "something dangerous".
You did not provide data, instead, you changed your tune significantly and now say:
I'm glad you recognized your mistake.
(my emphasis)
I asked you to provide data to back up the assertion that ETD systems are particularly good at identifying "something dangerous".
You did not provide data, instead, you changed your tune significantly and now say:
I'm glad you recognized your mistake.
Originally you said:
(my emphasis)
I asked you to provide data to back up the assertion that ETD systems are particularly good at identifying "something dangerous".
You did not provide data, instead, you changed your tune significantly and now say:
I'm glad you recognized your mistake.
(my emphasis)
I asked you to provide data to back up the assertion that ETD systems are particularly good at identifying "something dangerous".
You did not provide data, instead, you changed your tune significantly and now say:
I'm glad you recognized your mistake.
It was a mistake only if one is willing to reduce the idea that alarms always indicate something dangerous. ETD alarms indicate that there is a chemical present that is also present in some explosives. In other words, something dangerous.
Splitting hairs serves no useful purpose, and neither makes the other right or wrong, it just makes the conversation inane when one party pretends obtuseness.
It is really sad that you can't admit that the TSA ETD machines often alert on items that are not dangerous. By any measure that is a false positive. Even worse is TSA inflicting these terroristic screenings on people who have done absolutely nothing to merit an item by item inspection of their belongings.
And you call me obtuse.
And you call me obtuse.
Once again, for those in the cheap seats: ETD systems alarm when a chemical is detected that warrants further investigation by the screening TSO. That does not make the alarm a “false alarm”, it makes it an alarm. One that must be investigated further.
Many of the chemicals the ETD systems detect have civilian uses other than to make explosives. Their presence in someone’s baggage is not really all that uncommon, but it does require a response from TSA. Maybe that is where you are having your issues, you are having difficulty telling the difference between an ETD alarm and a “false positive”.
I don’t have that issue, so now you have a riddle to solve. Glad I could help you.
#47
Join Date: Dec 2010
Posts: 2,425
That does not make the alarm a “false alarm”, it makes it an alarm.
ETD alarms indicate that there is a chemical present that is also present in some explosives. In other words, something dangerous.
Once again, for those in the cheap seats: ETD systems alarm when a chemical is detected that warrants further investigation by the screening TSO. That does not make the alarm a “false alarm”, it makes it an alarm.
I don’t have that issue, so now you have a riddle to solve. Glad I could help you.
#48
Join Date: Oct 2010
Posts: 516
As an aside, you should ask your local supermarket to put the hand lotion behind the counter. Your training teaches you that it is "dangerous"!
#49
Join Date: Feb 2008
Location: Nashville, TN
Programs: WN Nothing and spending the half million points from too many flights, Hilton Diamond
Posts: 8,043
I am familiar with go/no gauges and other such testing devices. While they are useful those testing methods are limited. TSA on the other hand has rolled out a machine that alerts on contact lens cleaner, hand lotion, and other harmless items. This in my mind clearly make these devices useless for the testing they are in place to do.
Since everyone is a suspected terrorist, the TSA must have some method to weed out people that do not need further checks. They pretend that the ETD is to find problems. What they are looking for are people that need no further check as they do not "trip" the alarm. The ETD used as an indicator of innocence by the lack of an alarm is correct almost 100% of the time.
#50
Join Date: Apr 2011
Posts: 142
Originally Posted by OldGoat
Originally you said:
I asked you to provide data to back up the assertion that ETD systems are particularly good at identifying "something dangerous".
You did not provide data, instead, you changed your tune significantly and now say:
I'm glad you recognized your mistake.
Originally you said:
I asked you to provide data to back up the assertion that ETD systems are particularly good at identifying "something dangerous".
You did not provide data, instead, you changed your tune significantly and now say:
I'm glad you recognized your mistake.
It was a mistake only if one is willing to reduce the idea that alarms always indicate something dangerous. ETD alarms indicate that there is a chemical present that is also present in explosives. In other words, something dangerous.
I am personally of the opinion that any WEI found to date via this method actually falls within or below the actual margin of error and that searching people at random would likely give as good a result - and at a significant cost savings.
Ron: I don't know if you have access to any, or all, of the data, but with what you do know (or can observe in your position) and since the purpose is to find WEI:
- Take the amount of actual WEI found by this method and divide it by the number of passengers where the machine has alarmed and multiply by 100 for a percentage. (Effective percentage of postive test results.)
- Take the amount of actual WEI found by this method and divide it by the total passengers tested and multiply by 100 for a percentage. (Percentage of true positive test results.)
- Take the total direct costs of testing (equipment, swabs, personnel, etc.) and divide that by the number of actual WEI found by this method. (Average direct cost per true positive test result.)
My guesses are that 1 is small, 2 is very small, and that 3 is significantly large, especially when reviewed against 1 and 2.
My point? The cost / benefit ratios would not appear to point to this an effective test method for finding WEI - a primary goal of the administrative searches by TSA.
As all of life comes with risks, the struggle is to learn how to balance those risks against the costs and rewards. Sometimes it works out that the costs involved (ETD testing) exceed the reward (finding WEI via ETD testing) for the limited risk that is present (number of WEI found via ETD testing). The sad part is, the same could be said for the (in)effectiveness of the AIT scanners.
#51
Suspended
Join Date: Dec 2010
Posts: 3,728
#52
FlyerTalk Evangelist
Join Date: Mar 2008
Location: DFW
Posts: 28,132
I believe the point being made, as well as the request for data, is to help determine whether the testing is effective or not. If the testing is effective at finding WEI, then people would likely be less resistant to it. As of now, the amount of WEI found through this testing appears to be negligible based on what has been reported to date.
I am personally of the opinion that any WEI found to date via this method actually falls within or below the actual margin of error and that searching people at random would likely give as good a result - and at a significant cost savings.
Ron: I don't know if you have access to any, or all, of the data, but with what you do know (or can observe in your position) and since the purpose is to find WEI:
My guesses are that 1 is small, 2 is very small, and that 3 is significantly large, especially when reviewed against 1 and 2.
My point? The cost / benefit ratios would not appear to point to this an effective test method for finding WEI - a primary goal of the administrative searches by TSA.
As all of life comes with risks, the struggle is to learn how to balance those risks against the costs and rewards. Sometimes it works out that the costs involved (ETD testing) exceed the reward (finding WEI via ETD testing) for the limited risk that is present (number of WEI found via ETD testing). The sad part is, the same could be said for the (in)effectiveness of the AIT scanners.
I am personally of the opinion that any WEI found to date via this method actually falls within or below the actual margin of error and that searching people at random would likely give as good a result - and at a significant cost savings.
Ron: I don't know if you have access to any, or all, of the data, but with what you do know (or can observe in your position) and since the purpose is to find WEI:
- Take the amount of actual WEI found by this method and divide it by the number of passengers where the machine has alarmed and multiply by 100 for a percentage. (Effective percentage of postive test results.)
- Take the amount of actual WEI found by this method and divide it by the total passengers tested and multiply by 100 for a percentage. (Percentage of true positive test results.)
- Take the total direct costs of testing (equipment, swabs, personnel, etc.) and divide that by the number of actual WEI found by this method. (Average direct cost per true positive test result.)
My guesses are that 1 is small, 2 is very small, and that 3 is significantly large, especially when reviewed against 1 and 2.
My point? The cost / benefit ratios would not appear to point to this an effective test method for finding WEI - a primary goal of the administrative searches by TSA.
As all of life comes with risks, the struggle is to learn how to balance those risks against the costs and rewards. Sometimes it works out that the costs involved (ETD testing) exceed the reward (finding WEI via ETD testing) for the limited risk that is present (number of WEI found via ETD testing). The sad part is, the same could be said for the (in)effectiveness of the AIT scanners.
#53
Join Date: Mar 2009
Posts: 1,972
#54
Join Date: Mar 2009
Posts: 1,972
I do understand your definition of "false positive", but realize that the "E" in ETD stands for "explosive". So an equally possible definition is that a "false positive" means that no explosives were found.
#55
Join Date: Nov 2008
Posts: 3,657
TSORon, I love how you contradict yourself within a single posting:
You use two different definitions of an "ETD alarm" in use here. They differ significantly. Which would you like to use?
ETD alarms indicate that there is a chemical present that is also present in explosives. In other words, something dangerous.
...
ETD systems alarm when a chemical is detected that warrants further investigation by the screening TSO. That does not make the alarm a “false alarm”, it makes it an alarm. One that must be investigated further.
...
ETD alarms indicate that there is a chemical present that is also present in some explosives. In other words, something dangerous.
...
ETD systems alarm when a chemical is detected that warrants further investigation by the screening TSO. That does not make the alarm a “false alarm”, it makes it an alarm. One that must be investigated further.
...
ETD systems alarm when a chemical is detected that warrants further investigation by the screening TSO. That does not make the alarm a “false alarm”, it makes it an alarm. One that must be investigated further.
...
ETD alarms indicate that there is a chemical present that is also present in some explosives. In other words, something dangerous.
...
ETD systems alarm when a chemical is detected that warrants further investigation by the screening TSO. That does not make the alarm a “false alarm”, it makes it an alarm. One that must be investigated further.
#56
Join Date: Oct 2010
Posts: 516
"ETD alarms indicate that there is a chemical present that is also present in explosives. In other words, something dangerous."
I don't think I misread that at all. Read in isolation, you may have one of two possible interpretations. Read in the context of the thread, he's saying the chemicals are dangerous. Recall that ha started the banter by saying that ETD systems are particularly good at identifying something dangerous, and now he apparently wants to justify the statement by saying that because an ETD identifies chemicals present in explosives, it identifies something dangerous.
But the fact that we read the text differently does highlight his lack of clarity.
#57
FlyerTalk Evangelist
Join Date: Mar 2002
Location: An NPR mind living in a Fox News world
Posts: 14,165
- Take the amount of actual WEI found by this method and divide it by the number of passengers where the machine has alarmed and multiply by 100 for a percentage. (Effective percentage of postive test results.)
- Take the amount of actual WEI found by this method and divide it by the total passengers tested and multiply by 100 for a percentage. (Percentage of true positive test results.)
- Take the total direct costs of testing (equipment, swabs, personnel, etc.) and divide that by the number of actual WEI found by this method. (Average direct cost per true positive test result.)
My guesses are that 1 is small, 2 is very small, and that 3 is significantly large, especially when reviewed against 1 and 2.
My point? The cost / benefit ratios would not appear to point to this an effective test method for finding WEI - a primary goal of the administrative searches by TSA.
As all of life comes with risks, the struggle is to learn how to balance those risks against the costs and rewards. Sometimes it works out that the costs involved (ETD testing) exceed the reward (finding WEI via ETD testing) for the limited risk that is present (number of WEI found via ETD testing). The sad part is, the same could be said for the (in)effectiveness of the AIT scanners.
#58
Join Date: Mar 2009
Posts: 1,972
My guesses are that 1 is small, 2 is very small, and that 3 is significantly large, especially when reviewed against 1 and 2.
My point? The cost / benefit ratios would not appear to point to this an effective test method for finding WEI - a primary goal of the administrative searches by TSA.
My point? The cost / benefit ratios would not appear to point to this an effective test method for finding WEI - a primary goal of the administrative searches by TSA.
#59
Join Date: Jan 2011
Location: in the sky
Posts: 490
aaand we will never know how many sociopathic raging psycho terrorists masterminding horrible and terrible mayhem upon us have suddenly come to their senses due to this invaluable deterrence factor which brings us back to the point that no point is needed for any of these exercises at all.
#60
Suspended
Join Date: Dec 2010
Posts: 3,728
It's not like there's a shortage of targets that would obtain even higher moral outrage than blowing up a plane, or a checkpoint line.