Posts filed under Stat of the Week (619)

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 June 8 2012.
• Statistics can be bad, exemplary or fascinating.
• The statistic must be in the NZ media during the period of June 2-8 2012 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.
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If you’d like to comment on or debate any of this week’s Stat of the Week nominations, please do so below!

Thanks for all those who nominated in last week’s Stat of the Week competition.

This week we’re awarding Jonathan Goodman’s nomination of some good reporting of migration statistics with explanations, figures for comparison and context in an article in the Dominion Post. We’ve talked about poor migration reporting in the past, so it is nice to see good reporting for a change!

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 June 1 2012.
• Statistics can be bad, exemplary or fascinating.
• The statistic must be in the NZ media during the period of May 26 – June 1 2012 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.
(more…)

If you’d like to comment on or debate any of this week’s Stat of the Week nominations, please do so below!

Thanks for all those who sent in a nomination last week for our Stat of the Week competition. Please enter this week’s competition too!

This week’s winner has been chosen to be Nick Iversen’s nomination of the New Zealand Herald’s editorial which says “Self-selecting polls show which option has the most supporters who care enough to cast a vote”:

The Herald appears to be trying to justify why they can headline bogus polls as news (https://www.statschat.org.nz/2012/05/13/bogus-polls-treated-as-news/).

But a self selecting poll does not in fact show which option has the most supporters among those who care to cast a vote.

The self-selectors did not select themselves based on their level of care. They selected themselves based on having internet access, reading the Herald web site, and willingness to participate in a bogus poll. They don’t represent any meaningful segment of NZ.

The poll is still bogus (even if they published the sample size).

James Russell from our department explains why this is our winner this week (even though there were some fantastic other nominations!):

Self-selection is one of many biases that can affect the results of a survey. In this case the winning post highlights that self-selection can have many filters imposed on it, including motivation to respond to the survey as a final probability filter (e.g. x% of people), however prior to that there are other filters such as access to the internet (z%) and reading the Herald website (y%).

In this simple case the probability of a random person responding is already at least a function of z% x y% x x%. This is certainly not a random subset and is unlikely to be a meaningful one of society. Internet polls can struggle from other fascinating biases such as viral hacking. These biases can never be completely avoided in any survey but any statistician should have some idea of the level of them and their potential impact on the results.

As the winning post, this highlights a methodological issue underpinning many of the statistics discussed on Stats Chat.

Congratulations Nick Iversen!

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 May 25 2012.
• Statistics can be bad, exemplary or fascinating.
• The statistic must be in the NZ media during the period of May 18-25 2012 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.
(more…)

Thanks for all those who sent in a nomination last week for our Stat of the Week competition. Please enter this week’s competition too!

With such a variety of nominations, it was hard for us to choose a winner but we particularly liked the critique of Conservative Party leader Colin Craig’s use of statistics from a Durex and Marie Clare surveys which was a hot topic of discussion in the country this week as well. (For details, see here and here. As per our rules, the first nominee of a particular statistic is eligible to win.

Savannah Post was the first to nominate this:

Aside from the fact that the statistic was obviously out of date, this is a classic example of quoting a statistic without giving any other information, potentially misleading readers and/or viewers. Quoting the number of men the average New Zealand woman has supposedly slept with in isolation gives no concept of how this statistic compares to similar countries, how the results were collected, which countries were included etc.

A disappointing misuse of statistics to promote the somewhat outdated concept that any woman who uses contraception is automatically promiscuous.

…closely followed by Patricia de Guzman:

Mr Craig has made this wild claim that young NZ women are the most promiscuous in the world when all he’s citing his information from are surveys conducted by a condom manufacturer (obviously people buying condoms will be having more sex; why buy them if you’re not planning on using them?) and Marie Claire (known to have sex info thus women reading this magazine are likely to be having more sex anyway).

Long story short, the sample from those surveys are not a representative of the NZ population of women. We don’t want the world thinking NZ women are promiscuous when there’s no proper evidence!

A big congratulations to Savannah.

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 May 18 2012.
• Statistics can be bad, exemplary or fascinating.
• The statistic must be in the NZ media during the period of May 12-18 2012 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.
(more…)

If you’d like to comment on or debate any of this week’s Stat of the Week nominations, please do so below!