Jan 16 2015
The World’s Most Dangerous Job? | James Lawther
“You shouldn’t believe everything you read on the internet, but according to some of the more reliable sources, during World War II:
- Over 12,000 Bomber Command aircraft were shot down
- 55,500 aircrew died.
- The life expectancy of a Lancaster bomber was 3 weeks
- Tail-gunners were lucky if they survived four missions.”
Source: www.squawkpoint.com
This is a great story both about effective visualization of series of events in space-time and about proper interpretation in the face of sample bias.
Manufacturing, thankfully, is less dangerous than flying bombers in World War II was, but it is still more dangerous than it should be. Posting the locations of injuries on a map of the human body is also an effective way to identify which body parts are most commonly affected, and which safety improvements are most effective.
But are all injuries reported? Many organizations blame the victims for lowering their safety metrics, and discourage reporting. As a consequence, we can expect under-reporting and a bias towards injuries severe enough that reporting is unavoidable.
If you get data on an entire population, or if you thoughtfully select a representative sample, you can avoid bias, but many of the most commonly used samples are biased, often in ways that are difficult to figure out.
Customer surveys of product quality, for example, are biased by self-selection of the respondents. Are unhappy customers more likely to take the opportunity to vent than happy customers to praise? If so, to what extent? The effect of self-selection is even stronger for posting reviews on websites.
See on Scoop.it – lean manufacturing
February 2, 2015 @ 2:19 am
One can use bias to fool it’s target audience. This video is a good example of this. http://youtu.be/sk7A56KVNBY
Imagine the results of the “supposed test” with the second twins smiling or angry facing.
If Talk Of Probability Makes Your Eyes Glaze Over… | Michel Baudin's Blog
November 22, 2016 @ 9:30 am
[…] bias can lead to dramatic mistakes, as in the example of damage patterns in returning aircraft in World War II. The military wanted to reinforce the parts that had been hit. After plotting the bullet hole […]