Re: Experimental vs observed data

<jabberwocky><div class="vbmenu_control"><a href="jabberwocky:;" onClick="newWindow=window.open('','usenetCode','toolbar=no,location=no, scrollbars=yes,resizable=yes,status=no,width=650,height=400'); newWindow.document.write('<HTML><HEAD><TITLE>Usenet ASCII</TITLE></HEAD><BODY topmargin=0 leftmargin=0 BGCOLOR=#F1F1F1><table border=0 width=625><td bgcolor=midnightblue><font color=#F1F1F1>This Usenet message\'s original ASCII form: </font></td></tr><tr><td width=449><br><br><font face=courier><UL><PRE>\n\nStrong_Field wrote:\n&gt; "davidmerritt" &lt;davidoff@davidmerritt.co.uk&gt; wrote in message\n&gt; news:davidmerritt.1gysyi@physicsforums.com...\n&gt;\n&gt;&gt;Models created in the physical sciences often have their methodolgy\n&gt;&gt;routed in experimental data, not observed data as in the social\n&gt;&gt;sciences....\n\n&gt; This is a well established view but I am interested in analysing it\n&gt; further. For instance, in physical sciences a characteristic\n&gt; experimental data is the measurement of an oscillator. Let\'s say we have\n&gt; a vertical pendulum P and we measure its period. We measure the distance\n&gt; from one extreme point A to the other extreme point B. We get a set of\n&gt; numbers, like, x1, x2, x3, and so on. By using these numbers we can\n&gt; model the behavior of the pendulum within the experimental error.\n&gt;\n&gt; In social sciences, let\'s say we measure the density of people entering\n&gt; the Wall Street subway station at 5 PM.\n&gt;\n&gt; We do this, for instance, by counting the number of people whose feet\n&gt; touch the first step of the entrance at exactly 5 PM. We get a series of\n&gt; numbers y1, y2, y3 and so on. Given these numbers I can model the\n&gt; density of people entering subway station within the experimental error\n&gt; as well as the motion of the pendulum.\n&gt;\n&gt; How are these two data set differ? Why one is an experimental data and\n&gt; the other observed data?\n\nThere is no difference in principle. All experimental data is observed.\nThe main difference between physics and social sciences is that in\nphysics one generally studies systems which are strongly constrained by\nthe experimental setting, so that they give much more predictable results.\n\nIn both cases, however, the correct model is that of a stochastic process,\nand physics and social sciences only differ in the size of the noise\nrelative to the signal. Sometimes to the extent that one can ignore the\nnoise and treat a physical system as deterministic, while a social system\ncan never be controlled well enough to make the remaining fluctuations\nnegligible.\n\n\nArnold Neumaier\n\n</UL></PRE></font></td></tr></table></BODY><HTML>');"> <IMG SRC=/images/buttons/ip.gif BORDER=0 ALIGN=CENTER ALT="View this Usenet post in original ASCII form">&nbsp;&nbsp;View this Usenet post in original ASCII form </a></div><P></jabberwocky>$Strong_Field$ wrote:
> "davidmerritt" <davidoff@davidmerritt.co.uk> wrote in message
> news:davidmerritt.1gysyi@physicsforums.com...
>
>>Models created in the physical sciences often have their methodolgy
>>routed in experimental data, not observed data as in the social
>>sciences....

> This is a well established view but I am interested in analysing it
> further. For instance, in physical sciences a characteristic
> experimental data is the measurement of an oscillator. Let's say we have
> a vertical pendulum P and we measure its period. We measure the distance
> from one extreme point A to the other extreme point B. We get a set of
> numbers, like, x1, x2, x3, and so on. By using these numbers we can
> model the behavior of the pendulum within the experimental error.
>
> In social sciences, let's say we measure the density of people entering
> the Wall Street subway station at 5 PM.
>
> We do this, for instance, by counting the number of people whose feet
> touch the first step of the entrance at exactly 5 PM. We get a series of
> numbers y1, y2, y3 and so on. Given these numbers I can model the
> density of people entering subway station within the experimental error
> as well as the motion of the pendulum.
>
> How are these two data set differ? Why one is an experimental data and
> the other observed data?

There is no difference in principle. All experimental data is observed.
The main difference between physics and social sciences is that in
physics one generally studies systems which are strongly constrained by
the experimental setting, so that they give much more predictable results.

In both cases, however, the correct model is that of a stochastic process,
and physics and social sciences only differ in the size of the noise
relative to the signal. Sometimes to the extent that one can ignore the
noise and treat a physical system as deterministic, while a social system
can never be controlled well enough to make the remaining fluctuations
negligible.

Arnold Neumaier

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