December 9, 2013
Stat of the Week Competition: December 7 – 13 2013
Each week, we would like to invite readers of Stats Chat to submit nominations for our Stat of the Week competition and be in with the chance to win an iTunes voucher.
Here’s how it works:
- Anyone may add a comment on this post to nominate their Stat of the Week candidate before midday Friday December 13 2013.
- Statistics can be bad, exemplary or fascinating.
- The statistic must be in the NZ media during the period of December 7 – 13 2013 inclusive.
- Quote the statistic, when and where it was published and tell us why it should be our Stat of the Week.
Next Monday at midday we’ll announce the winner of this week’s Stat of the Week competition, and start a new one.
The fine print:
- Judging will be conducted by the blog moderator in liaison with staff at the Department of Statistics, The University of Auckland.
- The judges’ decision will be final.
- The judges can decide not to award a prize if they do not believe a suitable statistic has been posted in the preceeding week.
- Only the first nomination of any individual example of a statistic used in the NZ media will qualify for the competition.
- Individual posts on Stats Chat are just the opinions of their authors, who can criticise anyone who they feel deserves it, but the Stat of the Week award involves the Department of Statistics more officially. For that reason, we will not award Stat of the Week for a statistic coming from anyone at the University of Auckland outside the Statistics department. You can still nominate and discuss them, but the nomination won’t be eligible for the prize.
- Employees (other than student employees) of the Statistics department at the University of Auckland are not eligible to win.
- The person posting the winning entry will receive a $20 iTunes voucher.
- The blog moderator will contact the winner via their notified email address and advise the details of the $20 iTunes voucher to that same email address.
- The competition will commence Monday 8 August 2011 and continue until cancellation is notified on the blog.
Rachel Cunliffe is the co-director of CensusAtSchool and currently consults for the Department of Statistics. Her interests include statistical literacy, social media and blogging. See all posts by Rachel Cunliffe »
Statistic: Almost three-quarters of the depressed New Zealanders who have gone to Sir John Kirwan’s website depression.org.nz are no longer depressed after finishing the six lessons the site offers
Source: NZ Herald
Date: 10 December 2014
The first line of the article states, “Almost three-quarters of the depressed New Zealanders who have gone to Sir John Kirwan’s website depression.org.nz are no longer depressed after finishing the six lessons the site offers.” Later we are told, “by October this year, just over 1.3 million people had looked at the site and 40,000 were registered as users.”
Further on it states:
• 26% did the second lesson.
• only 3% (392 people) completed all six lessons (although it doesn’t state 3% of what – it would appear that it is 3% of the 26% that made it past the second lesson)
• Seven-eighths (87%) of the users were classified as depressed when they registered
• But 48% of those who started depressed and completed the second lesson were no longer depressed, and 71% of those who started depressed and completed all six lessons were no longer depressed.
So, 40,000 people registered of whom 87% were classified as depressed i.e. 34,800. 26% of this number (9048) completed the second lesson (this is assuming that those who registered and were not classified as depressed, didn’t continue with the lessons; some may have, which is in itself, depressing). Of these, 48% (4343) were no longer depressed after the second lesson. Of the remaining 4705, only 392 went on to complete all six lessons (meaning the difference of 5097 are likely still depressed, or at the least, highly unmotivated). Of these 392 people, 278 are no longer depressed (and the remaining 114 are still depressed, and looking for the seventh lesson).
Therefore we have 34,800 depressed registered site users of whom 4621 are no longer depressed which is 13% of those who initially registered.
Technically, the claim in the opening line is correct: that nearly three-quarters of those who completed six lessons were no longer depressed. But this accounts for 278 people of the 1.3 million who visited the site (although it is also unclear if these are unique visitors…) or of the 40,000 registered or of the 34,800 initially determined as depressed.
Elsewhere the article states, “other research suggested… 10 to 15 per cent would have stopped being depressed anyway”.
So it is possible that the 13% the site claims as successes may have simply stopped being depressed.
Depressingly, the data presented shows that it is possible that Sir John Kirwan’s depression website might be entirely ineffectual.
10 years ago
Statistic: Food prices have been creeping up by $2 a week over the last three decades.
Source: New Zealand Herald
Date: 13 December 2013
This statement is obviously wrong since food prices increase geometrically, not arithmetically.
Perhaps that point is too subtle to make to be a Stat of the Week. Until you do the sums.
Subtract $2 a week from today’s food prices and do this for a decade. If x is today’s prices then the prices 3 decades ago is x – $3120.
Food prices 3 decades ago were not negative so x must be greater than $3120.
So food prices today must be at least $3120 per week. No wonder mothers are skipping meals to feed their kids!
10 years ago
Statistic: There is no evidence of any general rise or fall in income inequality since 2007
Source: The Listener
Date: 12 December 2013
I’d like to put in a good word for the Listener getting it right on inequality. Their statement largely agrees with Thomas Lumley’s statistics showing the same thing at https://www.statschat.org.nz/2013/12/09/inequality-in-nz/.
This contrasts with the Herald which, interestingly, comes from the same stable as the Listener. The Herald reported (http://www.nzherald.co.nz/nz/news/article.cfm?c_id=1&objectid=11166484) that the gap between rich and poor is widening.
A Herald letter to the editor writer yesterday stated that NZ had “entrenched and growing inequality.” Obviously not a StatsChat or Listener reader.
10 years ago