For statistics to have any value for decisionmaking they need to be verified and checked for consistency and accuracy.
It is heartening to see Sir Michael Scholar, the head of the new statistics authority, rapping the Government's knuckles for overriding the concerns of the National Statistician and her staff and publishing unverified statistics for the decline of knife crime.
There is a lot of moral hazard in this area for politicians. They can select the statistics which suit their case, knowing that even a rebuke from Sir Michael will go unreported by the tabloids because it is all far too technical. The risk is that public confidence is further eroded in Government statistics - Sir Michael needs a regular platform, probably on the BBC where he can explain the use and abuse of statistics. Then the public will wise up to this kind of chicanery.
Showing posts with label statistics. Show all posts
Showing posts with label statistics. Show all posts
Sunday, 14 December 2008
Monday, 19 May 2008
Misleading percentages
"House sales to fall by 40%" is the headline used to attract attention by Yahoo to a report from the Chartered Surveyors.
This is serious, but it is also misleading. When you read on you find that house prices are expected to fall by 5%, whilst house sales plummet 40%.
The immediate downside risk is to the estate agents, the surveyors, and the removal companies.
But sales and prices are easily confused and most will think that the prices are to fall precipitously. They may, but that is not what the report expects.
This is serious, but it is also misleading. When you read on you find that house prices are expected to fall by 5%, whilst house sales plummet 40%.
The immediate downside risk is to the estate agents, the surveyors, and the removal companies.
But sales and prices are easily confused and most will think that the prices are to fall precipitously. They may, but that is not what the report expects.
Sunday, 4 May 2008
Off the record
The National Archive at Kew , guardian amongst other things of the Domesday Book, has a deserved reputation for protecting the national records. It has tight control on all access to its material as theft is one of the major risks it faces.
What has recently come to light, aired on a BBC radio show, is that someone has been adding material to the archive without permission, creating false records which have then been used, it is thought, to support sensationalist claims in books relating to World War 2 events. Over 20 false records have been identified and new controls are now in place to stop this happening again.
Once there is doubt about the records then the damage to the reputation of the National Archive is very signficant because researchers do not know whether the document they are quoting is authentic or not.
What has recently come to light, aired on a BBC radio show, is that someone has been adding material to the archive without permission, creating false records which have then been used, it is thought, to support sensationalist claims in books relating to World War 2 events. Over 20 false records have been identified and new controls are now in place to stop this happening again.
Once there is doubt about the records then the damage to the reputation of the National Archive is very signficant because researchers do not know whether the document they are quoting is authentic or not.
Wednesday, 16 April 2008
A 13 year old deserves respect - be very afraid
You may have missed this. It is a remarkable addition to the library of poorly calculated statistics. Great story - look on 13 year olds with more respect . I found this on the Straits Times Site:
April 16, 2008
German boy, 13, corrects Nasa's asteroid figures
BERLIN - A 13-year-old German schoolboy corrected Nasa's estimates on the chances of an asteroid colliding with Earth, a German newspaper reported on Tuesday, after spotting the boffins had miscalculated.
Nico Marquardt used telescopic findings from the Institute of Astrophysics in Potsdam (AIP) to calculate that there was a 1 in 450 chance that the Apophis asteroid will collide with Earth, the Potsdamer Neuerster Nachrichten reported.
Nasa had previously estimated the chances at only 1 in 45,000 but told its sister organisation, the European Space Agency (ESA), that the young whizzkid had got it right.
The schoolboy took into consideration the risk of Apophis running into one or more of the 40,000 satellites orbiting Earth during its path close to the planet on April 13 2029.
Those satellites travel at 3.07km a second, at up to 35,880km above earth - and the Apophis asteroid will pass by earth at a distance of 32,500km.
If the asteroid strikes a satellite in 2029, that will change its trajectory making it hit earth on its next orbit in 2036.
Both Nasa and Nico agree that if the asteroid does collide with earth, it will create a ball of iron and iridium 320m wide and weighing 200 billion tonnes, which will crash into the Atlantic Ocean.
The shockwaves from that would create huge tsunami waves, destroying both coastlines and inland areas, whilst creating a thick cloud of dust that would darken the skies indefinitely.
The 13-year old made his discovery as part of a regional science competition for which he submitted a project entitled: Apophis - The Killer Astroid.
April 16, 2008
German boy, 13, corrects Nasa's asteroid figures
BERLIN - A 13-year-old German schoolboy corrected Nasa's estimates on the chances of an asteroid colliding with Earth, a German newspaper reported on Tuesday, after spotting the boffins had miscalculated.
Nico Marquardt used telescopic findings from the Institute of Astrophysics in Potsdam (AIP) to calculate that there was a 1 in 450 chance that the Apophis asteroid will collide with Earth, the Potsdamer Neuerster Nachrichten reported.
Nasa had previously estimated the chances at only 1 in 45,000 but told its sister organisation, the European Space Agency (ESA), that the young whizzkid had got it right.
The schoolboy took into consideration the risk of Apophis running into one or more of the 40,000 satellites orbiting Earth during its path close to the planet on April 13 2029.
Those satellites travel at 3.07km a second, at up to 35,880km above earth - and the Apophis asteroid will pass by earth at a distance of 32,500km.
If the asteroid strikes a satellite in 2029, that will change its trajectory making it hit earth on its next orbit in 2036.
Both Nasa and Nico agree that if the asteroid does collide with earth, it will create a ball of iron and iridium 320m wide and weighing 200 billion tonnes, which will crash into the Atlantic Ocean.
The shockwaves from that would create huge tsunami waves, destroying both coastlines and inland areas, whilst creating a thick cloud of dust that would darken the skies indefinitely.
The 13-year old made his discovery as part of a regional science competition for which he submitted a project entitled: Apophis - The Killer Astroid.
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