Statistical Analysis Stack Exchange
Statistical Analysis Stack Exchange

Questions tagged [measurement]

Measurement is the assignment of a value (numeric or otherwise) to an observation.

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Under what conditions should Likert scales be used as ordinal or interval data?

Many studies in the social sciences use Likert scales. When is it appropriate to use Likert data as ordinal and when is it appropriate to use it as interval data?
A Lion
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What is perplexity?

I came across term perplexity which refers to the log-averaged inverse probability on unseen data. Wikipedia article on perplexity does not give an intuitive meaning for the same. This perplexity measure was used in pLSA paper. Can anyone explain…
Learner
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How can I align/synchronize two signals?

I'm doing some research but have come stuck at the analysis stage (should've paid more attention to my stats lectures). I've collected two simultaneous signals: flow rate integrated for volume and change in chest expansion. I'd like compare the…
person157
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Finding most likely permutation

[Hoping that this is the right Stackexchange site; inspired from a true story seen at work] Joe has a measuring instrument and $n$ objects to be measured (say, a scale and $n$ weights). He measures each one, obtaining a list of measurements…
GioMott
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Is there a measure of 'evenness' of spread?

I looked up on the web, but couldn't find anything helpful. I'm basically looking for a way to measure how 'evenly' a value is distributed. As in, an 'evenly' distributed distribution like X: and an 'unevenly' distributed distribution Y of roughly…
Ketan
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Best distance measure to use to compare vectors of angles

Context I have two sets of data that I want to compare. Each data element in both sets is a vector containing 22 angles (all between $-\pi$ and $\pi$). The angles relate to a given human pose configuration, so a pose is defined by 22 joint…
Josh
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How do economists quantify black market operations?

I was doing a lot of research into organized crime in East Asia for a project as a favor to an author-friend of mine, and I noticed that there were noted economists and journalists who, in conjunction, estimate the value of black market operations…
Aarthi
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What criteria must be met in order to conclude a 'ceiling effect' is occurring?

According to The SAGE Encyclopedia of Social Science Research Methods… [a] ceiling effect occurs when a measure possesses a distinct upper limit for potential responses and a large concentration of participants score at or near this limit.…
ceiling
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Measure the uniformity of a distribution over weekdays

I have a similar problem to the question asked here: How does one measure the non-uniformity of a distribution? I have a set of probability distributions over the days of the week. I want to measure how close each distribution is to…
EBartrum
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Is regression of x on y clearly better than y on x in this case?

An instrument used to measure the levels of glucose in a person's blood is monitored on a random sample of 10 people. The levels are also measured using a very accurate laboratory procedure. The instrument measure is denoted by x. The laboratory…
Neo
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How to compare measurements and uncertainties made with different measuring instruments?

I have two different measuring instruments, A and B, both measure the same physical property $x$ of an object but with different "quality": B gives measurements with a known uncertainty while I do not know the uncertainty in the measurements given…
Alessandro Jacopson
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Linear regression model that best suit for data with errors

I'm looking for linear regression algorithm that is most suitable for a data whose independent variable (x) has a constant measurement error and the dependent variable (y) has signal dependent error. The above image illustrates my question.
user46178
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Can binary data be ordinal?

Binary data is often mentioned as a nominal sub-category, especially in such examples as female/male, smoker/non-smoker, etc. However, binary data with such values as pass/fail, correct/incorrect, absent/present, etc, seems to give some weight to…
Billy the Poet
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Using two sensors instead of one: Statistically meaningful?

We are using resp. manufacturing a certain device which measures, among others, the humidity of liquids. I got asked by a colleague if it makes sense to use two sensors instead of one (which a competitor is apparently doing). Mainly, in a…
Ben
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Primitive length measurements

A measuring rod has length $u$ (for "unit") and a long object has length $x$. Suppose $u$ is laid end to end $i$ times and $x$ is laid end to end $j$ times. We want to observe whether $iu\ \left\{\begin{array}{c} < \\ = \\ > \end{array}\right\}\ …
Michael Hardy
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