Talk:Measurement

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Contents 1 Question 2 Why on earth does "Mensuration" redirect here? 3 The good, the bad, and the ugly. 4 The neverending battle. 5 Pre-metric measures

[edit] Question

i have a project due i need to know info about a balance scale

What information do you need? You may be better off asking at Wikipedia:Reference desk. There are a few article spread out on the topic. See balance, scale (measurement), and weighing scale to start your search. - Taxman 18:13, Apr 7, 2005 (UTC)

[edit] Why on earth does "Mensuration" redirect here?

Mensuration is a Renaissance concept of meter in music. The word doesn't even show up on this page. It shouldn't redirect here. Blargh. --YixilTesiphon ^{Say hello}_{Be shallow} 18:14, 30 January 2006 (UTC)

"Mensuration" also is an old word for "measurement", which is why it redirects here. Rick Norwood 13:53, 9 April 2006 (UTC)

[edit] The good, the bad, and the ugly.

There are a number of good points to this article, but the first sentence is both needlessly complex and needlessly restrictive. I will attempt a rewrite. Rick Norwood 13:55, 9 April 2006 (UTC)

I'm all for simplifying things where possible, but there are a number of issues with the proposed changes. A measurement is the act of discovering .... A measurement is not an act, it is the result of a pocess. Measurement is a process which extends from calibration to the act of obtaining particular measurements. There are four different levels of measurement -- this schema has been repeatedly criticized yet it is treated as though fact. The use of statistics to estimate the measurement of a property of a population from the measurement of that property in a sample is an important modern technique of measurement. This really doesn't make anything simpler too me -- and it is out of context. It is also very misleading. Perhaps you could provide some citations for changes and new points. Holon 14:22, 9 April 2006 (UTC)

Let's see if we can come to an agreement. The version you restored preferences measurement in classical physics and engineering over all other sorts of measurement. Do we really want to do that?

Measurement is both an act and the result of that act. "My measurement of the object resulted in a measurement of 3 meters." I have no problem, however, preferencing the result of the act rather than the act itself. I agree that that is more in accord with what follows.

"Measurement is a process...", however, returns to measurement as an act rather than measurement as a result.

"Four different levels..." I have no idea what this is about. I just kept it from the earlier version of the article, and it is still there after your reversion.

I am not sure what your problem is with statistics, but I'm happy to discuss it.

Comments and suggestions? Rick Norwood 14:52, 9 April 2006 (UTC)

Do we want to preference measurement in physics over all other sorts? To answer this, firstly a bit of background to let you know where I'm coming from. The two of the predominant perspectives about measurement have been referred to as the classical theory and the representational theory. The following is a brief characterization of these:

Essentially, then, there are two features dividing the classical and representational theories of measurement: the role of ratios of quantities and the place of numbers. According to the classical theory, these two are logically connected: ratios of quantities are numbers, and this fact is the basis of measurement. According to the representational theory, numbers do not derive from ratios of quantities. They are quite independent of them and the place of numbers in measurement is determined by the structural similarity between qualitative and quantitative systems. Hence, according to the representational theory, numbers are assigned to empirical entities in measurement. According to the classical theory, numbers are discovered as relations between empirical entities in measurement. (Michell, 1993, p. 190).

The classical view is standard throughout the physical sciences because the very act of expressing the magnitude of a quantity as a number of uits implies it (e.g. Terrien, 1980). However, S. S. Stevens proposed a definition of measurement which has had a wide impcact in the social sciences even though it is at odds with the definition in the physical sciences (Michell, 1999, pp. 16-20). Stevens also proposed the so-called levels of measurement.

To answer your question, I'd rather give preference to measurement as it is understood throughout the natural sciences. Things like the index of consumer confidence and the Dow Jones industrial average are indices, not measurements, as implied by their labels. So it depends what you mean by 'all other sorts of measurement'. Measurement is sometimes used loosely to refer to all sorts of things, but personally I would stick to its meaning in the natural sciences, with some recognition of other usage. I'm open to debate on this point of course.

On levels of measurement, the current wording has 'proposed', whereas you changed it to 'there are four different levels' (I understand why you did so but it gives the schema a more definitive status). Personally, I'd leave this out of a definition, so perhaps we could do this (others may disagree).

You changed opening sentence to: A measurement is the act of discovering the ratio of a magnitude to a given unit magnitude of the same type. Common usage is that a measurement is the result of measuring on a particular occasion. Measurement is the estimation of ratios, which is a process involving instrumentation, calibration, the act of using instruments to obtain measurements, and so on.

There is also an issue with referring to measurment as an act. Doing so emphasizes one aspect of measurement as a whole: the act of using an instrument to obtain a particular measurement. Measurement, as understood in scientific literature, is far more than this. Again, maybe we need to differentiate between different uses of the term?

You added: The use of statistics to estimate the measurement of a property of a population from the measurement of that property in a sample is an important modern technique of measurement. I'm not sure what you're trying to say here. Can you give an example? A lot of statistical methods require measurements as a starting point because arithemtic operations depend on having measurements (e.g. anything involing ANOVA). My doctoral (and current) research is in the area of probabilistic measurement. Even here, statistics is not used to estimate measurements, so I am unsure what you mean. Statistics is used in the estimation of standard errors. Statistics like means are sometimes referred to as 'measures of central tendency', but they are not measurements per se; rather they characterize a property of a set of measurements. But I am not sure if this is what you mean?

References:

• Michell, J. (1993). The origins of the representational theory of measurement: Helmholtz, Hölder, and Russell. Studies in History and Philosophy of Science, 24, 185-206.
• Michell, J. (1999). Measurement in Psychology. Cambridge: Cambridge University Press.
• Terrien, J. (1980). The practical importance of systems of units; their trend parallels progress in physics. In A.F. Milone & P. Giacomo (Eds.), Proceedings of the International School of Physics ‘Enrico Fermi’ Course LXVIII, Metrology and Fundamental Constants (pp. 765-9). Amsterdam: North-Holland.

Cheers. Holon 04:56, 10 April 2006 (UTC)

It sounds like you can make an interesting contribution to the article, rather than just revert to an earlier version that still contains things (such as "four kinds of measurement") that you object to.

My objection to preferencing measurement in the natural sciences and physics in particular is that it ignores the use of measurement in construction work, engineering, and many other fields. The stuff about the Dow Jones was another attempt to make clear something in the earlier version that you reverted back to.

As for statistics, since it is your area, why don't you write something about the use of statistics to obtain measurements, and the relative accuracy of statistics over direct measurement of every member in a population, in obtaining an average measurement for the population. Rick Norwood 12:51, 10 April 2006 (UTC)

Yeah, you're right I sould try to improve the article. As you say, it has some good points but the opening is not great as is. Can you elaborate on what you mean about measurement in construction, engineering and so on? The way I'd go is to define and characterize measurement in general terms, and mention that measurement is fundamental to a wide and diverse range of fields and commercial applications. Thoughts? On Dow Jones etc., understood. On statistics, I should include something on maximum likelihood estimation in probabilistic measurement, true. Averages and so forth are best dealt with separately I think -- measurement is principally about individuals not populations (I assume you're referring to the use of Bayesian stats but this is really getting away from the fundamentals of measurement imv, better placed elswhere). I'll have a go when I get some time. In the mean time, if you want to make changes, go for it and I'll take a look when I can. Cheers Rick. Holon 03:29, 11 April 2006 (UTC)

I agree. I don't think the article needs to narrow down the many areas in which measurements are used. My objection was to giving precedence to, for example, science over engineering. I'm going to make a few changes, you make more when you have the time. Rick Norwood 13:00, 11 April 2006 (UTC)

Sorry Rick, didn't see this entry. Have already made some changes. See what you think and I'll check out any more you make. Would appreciate feedback -- be honest, it needs to be accessible. Holon 13:03, 11 April 2006 (UTC)

It turns out we were editing at the same time. Your edit looks fine, but here is mine, just in case you want to use anything from it in your edit.

Measurement is the process of estimating the ratio of a magnitude to a defined unit of the same type. It also refers to the result of that process. A measurement of the length of a plank results in a measurement of 9 meters.

While a measurement is usually given as a number followed by a unit, every measurement really has three parts, the estimate, an error bound, and a probability that the actual magnitude lies within the error bound of the estimate. For example, a measurement of a plank might result in a measurement of 9 meters plus or minus 0.01 meters, with a probability of 99%.

A measurement should be distinguished from a count. A measurement is a real number, and is never exact. A count is a natural number and may be exact. For example, a non-handicapped person has exactly ten fingers and thumbs on their two hands.

Statistics are often used to estimate counts and measurements, and if used carefully can result in greater accuracy than direct counts and measurements.

In scientific research, measurement is essential. One of the characteristics that distinguishes science from pseudoscience is careful measurements that fall within predicted perameters. Rick Norwood 13:21, 11 April 2006 (UTC)

Have incorporated some of your edits. Much better overall now I think. Holon 13:40, 11 April 2006 (UTC)

Rick, glad you're still checking on this article. Do you think the structure is Okay? There are a couple of bits that are repetitive now, and I'm going to try to get to those. Yes, I thought about planets being contentious, but most people wouldn't think of that. However, I thought your example of ten digits in base 10 was really nice personally. Holon 06:33, 27 April 2006 (UTC)

[edit] The neverending battle.

Yes, this page is still on my watch list -- though I've cut about a third of the pages on my watchlist, just because time is finite. Wikipedia has many virtues, mainly because people love to write about subjects that interest them, but it also has a problem with repeated edits leaving articles choppy and repetitious. From time to time, somebody has to put in the hours to go over the article from beginning to end, fixing small problems. Then, about half the time, all that work gets reverted by somebody who objects to one small item on the list. Rick Norwood 14:21, 27 April 2006 (UTC)

[edit] Pre-metric measures

User:24.248.103.130 recently added the following sentence to our history section:

The standard roman measurement of wheat is a modius.

This didn't work in with the existing text at all, so I deleted it. But it does highlight our current History section's lack of coverage of early measurement systems. Surely these are worth a mention here. At present the main article referred to (History of measurement) almost seems to be about a completely different topic. -- Avenue 00:07, 2 June 2006 (UTC)