# Branch on sampling bias

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If 50% of all the people in a population of 20000 people drink coffee in the morning, and if you were repeat the survey of 377 people ("Did you drink coffee this morning?") many times, then 95% of the time, your survey would find that between 45% and 55% of the people in your sample answered "Yes".

Be careful of survey bias.

if you were repeat the survey of 377 people many times

Imagine I wanted to know the % of the population that smoked. If I survey the 377 people in multiple smoking areas of pubs the results of the survey will wind up being biased towards people smoking.

Edited by fiveworlds

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In survey sampling, bias refers to the tendency of a sample statistic to systematically over- or under-estimate a population parameter.

<Large chunk of webpage removed - please only quote enough to provide the gist or the flavour of an article; wholesale cut'n'paste, even when referenced, is not acceptable. >

Reference: http://stattrek.com. Bias in survey sampling. Retrieved Sep 09, 2014 from stattrek.com: http://stattrek.com/survey-research/survey-bias.aspx/sampling-error

Edited by imatfaal
to remove large cut'n'paste

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@Fiveworlds: You are correct that bias (or correlations) are important for practical work. However, complicating the picture will probably not help the OP understanding the original question. So I recommend against expanding on this point, even if it may be interesting/fun for you. Also note that the web-page you used as a source has terms and conditions that explicitly state that you need a written permit to distribute the contents.

Edited by timo

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Also note that the web-page you used as a source has terms and conditions that explicitly state that you need a written permit to distribute the contents.

Also note that internet copyrights are under the terms and conditions of the internet hardware public license.

CERN relinquishes all intellectual property rights to this code, both source and binary and permission is given to anyone to use, duplicate, modify and distribute it."

Also note that the web-page you used as a source has terms and conditions that explicitly state that you need a written permit to distribute the contents.

"As a User (the Licensee) of the licensed software, you cannot redistribute the original or a derivative work with fewer rights than the ones you yourself received."

Edited by fiveworlds

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Moderator Note

fiveworlds

Please do not cut'n'paste entire (or a large fraction of) webpages onto this site; if in doubt stick to a paragraph or a short abstract.

For your guidance - neither of the two quoted sections in your latest post apply to the material you posted; cern relinquished their rights but cannot bind future authors of unrelated material, and the copyleft maxim is not necessarily germane to material which is explicitly copyrighted and would not allow distribution in this case anyway.

When some person or organisation has spent time and effort creating a webpage - a short quote, a description, and a link or citation would seem fair usage; wholesale quoting would not.

Do not respond to this moderation within the thread - any response will be hidden from view

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Moderator Note

Also note that at the bottom of that page it says

That's a big 'ol "Do not copy" sign

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Also note that at the bottom of that page it says

That's a big 'ol "Do not copy" sign

Nope you have to be registered for copyright. You also need proof of citizenship. There is other considerations too Einstein's theory of relativity is public domain in the US however still copyrighted in Germany. http://en.wikipedia.org/wiki/Wikipedia:Non-U.S._copyrights

Edited by fiveworlds

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CERN is not american and US copyright laws (whatever they are) do not apply in Europe.

In particular in UK law copyright exists on any copyrightable material from the moment of its creation and does not have to be asserted or registered with anyone (with or without a fee).

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Well here Cern was awarded their copyrights and subsequently

(6)Copyright shall not subsist in a work which infringes, or to the extent that it infringes, the copyright in another work.

In particular in UK law copyright exists on any copyrightable material from the moment of its creation and does not have to be asserted or registered with anyone (with or without a fee).

@studiot

Edited by fiveworlds

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So you have published a link to a commercial organisation that takes money for a registration process in the UK?

How does that affect UK law?

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Copyright does not subsist in a literary, dramatic or musical work unless and until it is recorded, in writing or otherwise; and references in this Part to the time at which such a work is made are to the time at which it is so recorded.

Edited by fiveworlds

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Moderator Note

FIVEWORLDS

OK - stop now. This is a hijack of a hijack.

And you are incorrect - quoting sections of an act without understanding is dangerous and misleading. Your latest quote merely means that copyright cannot come into play until some form of recording of the work is made (ie a written copy, an audio tape, a digital video etc); recording in this instance does not mean registration.

You do not need to be a citizen under many jurisdictions - residence will suffice. And most jurisdictions have reciprocal arrangements and agreement with other states.

Any further discussion on copyright will be hidden.

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studiot

I realise your post was cross-posted with my moderation calling for an end of discussion regarding copyright - but I think it best for the post to be hidden nonetheless; otherwise it calls out for reply. Apologies

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