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6
votes
3answers
350 views

What does “curvilinear” mean?

As far as I can tell, curvilinear is defined vaguely but means the same as nonlinear. Is that correct? Or does curvilinear have a distinct definition?
1
vote
1answer
47 views

What is the difference between sample and outcome? (plus events and observations)

I was sure that these are the same things but I do not get the difference reading about mass probability function Suppose that $X: S → A (A \subseteq R)$ is a discrete random variable defined on ...
0
votes
0answers
10 views

what dates to use to calculate length of follow up

I am dealing with a set of surgery patient data, have the date of surgery, date of discharge, and date of the last follow-up visit. I am wondering that for calculating the duration of follow-up, do I ...
4
votes
1answer
80 views

Has the parameter $\frac{1}{\sqrt{2(n-1)}}$ a name?

Has the parameter $\displaystyle \frac{1}{\sqrt{2(n-1)}}$ a name? $n=\text{number of observations}$
1
vote
1answer
25 views

Explanation of order of integration in the context of cointegration

Please explain the meaning of 'order of integration' when talking about cointegration. An explanation with some examples would be great.
1
vote
1answer
82 views

What is the difference between a parametric test and non-parametric tests? [duplicate]

Please explain the difference between a parametric and a non-parametric test. Do all data mining techniques come under the non-parametric category?
1
vote
0answers
20 views

Configural frequency analysis

What do you think about configural frequency analysis? http://en.m.wikipedia.org/wiki/Configural_frequency_analysis I personally love the idea to extract types and antitypes in heterogenous samples ...
1
vote
0answers
24 views

Window models in stream data processing

Reading about data stream clustering I met the next terms: landmark window model, sliding window model, damped window. As to sliding window it's clear - oldest data escape the scope, the new data ...
0
votes
1answer
47 views

What is the $p$ in Cook's distance?

In the equation for Cook's distance: $$D_i = \frac{\sum_{j=1}^{n}(\hat{y}_j - \hat{y}_{j(i)})^2}{p MSE}$$ the value of $p$ is defined as "the number of fitted parameters in the model." What does ...
0
votes
1answer
29 views

What is a seasonality of a data stream ? How to use it to estimate a stream attributes ?

I am trying to understand what is the rigorous definition of seasonality is, but couldn't find it. Is it a mathematical tool at all? I need to analyze a stream coming from one source and be able to ...
1
vote
1answer
81 views

Simple definition of elliptical distribution

I'm looking for a simple explanation of what an elliptical distribution is and how it differs from a non-elliptical distribution. My knowledge of stats is very basic; Wikipedia was not much help on ...
1
vote
0answers
24 views

Question about the frequency definition of probability

In the book, it is written that the relative frequency or the frequency ratio gradually tends to become more or less constant as N becomes larger and larger. It is also mentioned that this is an ...
2
votes
0answers
45 views

What is the null hypothesis in the definition of Sensitivity and Specificity?

I have hard time to understand that what is the null hypothesis in the definition of Sensitivity and Specificity here? I'm student of Statistics and from my little knowledge in this field I can see ...
8
votes
2answers
796 views

Is variation the same as variance?

This is my first question on Cross Validated here, so please help me out even if it seems trivial :-) First of all, the question might be an outcome of language differences or perhaps me having real ...
1
vote
1answer
104 views

Why does doing LDA on a outer product of input matrix gives same result as doing PCA of the input matrix?

Why does doing Linear Discrimenant Analysis (LDA) on a outer product of input matrix gives same result as doing Principal Component Analysis (PCA) of the input matrix? Not exactly sure where this ...
5
votes
2answers
120 views

Definition of statistical model in case of hierarchical model

In wikipedia the definition of a parametric model is the following: A parametric model is a collection of distributions, each of which is indexed by a unique finite-dimensional parameter: ...
1
vote
1answer
88 views

Difference in meaning of these terms: Dataset vs Corpus

I have a question pertaining to definition of terms that I couldn't find answer for. What's the difference between Dataset and Corpus? I've seen them being used almost interchangeably. My ...
5
votes
1answer
49 views

Deviate vs. Variable

What is the difference between a multivariate normal random deviate and a random variable? More specifically, I suppose, what exactly is a deviate?
0
votes
0answers
52 views

What is a “subject” in ICC?

I have been working in R and have finally got some code working regarding intraclass correlation coefficients. In the output I get something called "subjects". I thought it was to do with the number ...
0
votes
1answer
65 views

Is true discovery rate (TDR) the same as true positive rate (TPR)?

This is a general question about the definition of true discovery rate (TDR) and true positive rate (TPR). It is more common to use TPR, defined as $\frac{TP}{TP+FN}$, and false discovery rate (FDR) ...
4
votes
1answer
153 views

What is a “factor” in factor analysis?

What is a factor from a linear algebra point of view? Is it a vector, matrix, basis, tuple, coordinate system or something else?
5
votes
1answer
286 views

Correct definition of number of parameters $K$ in Akaike Information Criterion

What is the term $K$ in Akaike information criterion? The AIC is defined as $2K-2log(L)$, where $L$ is the maximized value of the likelihood function for the estimated model. On the internet, I found ...
5
votes
2answers
500 views

What is the difference between posterior and posterior predictive distribution?

I understand what a Posterior is, but I'm not sure what the latter means? How are the 2 different? Kevin P Murphy indicated in his textbook, Machine Learning: a Probabilistic Perspective, that it is ...
0
votes
0answers
74 views

Is there a conventional definition of $\bumpeq$ in statistics?

I was reading a paper on Bayesian curve fitting (Dimatteo et. al. Bayesian curve-fitting with free-knot splines, 2001) and came across the symbol $\bumpeq$. It is used a few times throughout the paper ...
3
votes
0answers
137 views

Confidence interval vs Significance level question

Until now I thought that the significance level and the confidence interval were the complement of each other, i.e. when some question asked me to carry out a hypothesis test with a $p %$ significance ...
3
votes
1answer
189 views

What is “ANOVA”?

Wikipedia says: Analysis of variance (ANOVA) is a collection of statistical models used to analyze the differences between group means and their associated procedures (such as "variation" among ...
1
vote
0answers
56 views

Explain probability measure and probability distribution

Dear statistics community, I seek your help to understand the jungle of concepts about probability theory. I am struggling to form a coherent understanding of terms like probability mass function, ...
6
votes
1answer
158 views

What does “principled” mean, as in “principled Bayesian analysis”?

I am generally curious what the term "principled" means. It was used in the title of an unpublished manuscript, "Combining Computer Models in a Principled Bayesian Analysis". In addition, Zhang 2004 ...
-1
votes
1answer
563 views

Some clear range and interval definitions

What is your or an offical (please provide link to citation) definition of range AND interval _? Or perhaps put in another way: what is the major important difference between the two terms _? My ...
2
votes
2answers
97 views

Forecasting the past?

More of a literacy question that stats, but I'm looking for correct terminology and the Google machine hasn't thrown anything up. You have explanatory data and observed data for 2000-2010. You have ...
1
vote
0answers
90 views

What is meant by the “level” of a time series?

In much of the literature I'm studying it's one of those terms that occurs frequently yet without a rigorous definition to be found. Specifically, I am told: For time-indexed random variables ...
0
votes
1answer
98 views

Can a confounding variable be correlated with the DV and not the IV?

Can a confounding variable be correlated with the DV and not the IV? I have heard of the DV being corr. but I can't find IV in any textbooks. I found this def. in Wiki: ...
5
votes
3answers
2k views

Difference between superpopulation and infinite population

What is the difference between Superpopulation and Infinite population? Please explain this with examples. Thanks!
2
votes
2answers
310 views

Arbitrariness of Euler's number in exponential of log-normal distribution

The Wikipedia article of the log-normal distribution says If $X$ is a random variable with a normal distribution, then $Y = \exp(X)$ has a log-normal distribution; likewise, if $Y$ is ...
1
vote
2answers
209 views

What's the difference between likelihood and confidence in claim being true

I'm reading the IPCC report on climate change from 2007. In their uncertainity guide they make a distinction between likelihood and levels of confidence. What's the difference between the terms? ...
10
votes
2answers
2k views

Do you reject the null hypothesis when $p < \alpha$ or $p \leq \alpha$?

This is clearly just a matter of definition or convention, and of almost no practical importance. If $\alpha$ is set to its traditional value of 0.05, is a $p$ value of 0.0500000000000... considered ...
1
vote
2answers
177 views

How is the standard definition of independence applied to time-series?

So, [Wikipedia says] that the standard definition of independence is: $f_{X,Y}(x,y) = f_X(x) f_Y(y)$ How is this applied to timeseries? How do we calculate each side of the equation? If we're ...
1
vote
0answers
87 views

How do you call a situation or a point at wich statistics data stops changing?

When I calculate a prediction, for instance I am trying to find out who is going to win elections and I do that by asking people who they voted on. After a certain number of answers my data will stop ...
1
vote
0answers
169 views

Length weighted median

In the field of genome assemblies in biology (the problem being reconstructing the genome from many, short random pieces of it, where a genome is one or more long strings of a limited alphabet), there ...
6
votes
1answer
128 views

How to define what a “sample” is?

If I give you three numbers that are independently and identically drawn from a standard normal distribution, then have I given you three samples or one sample? If the answer is one sample, then is ...
5
votes
1answer
14k views

What is the difference between “margin of error” and “standard error”?

Is "margin of error" the same as "standard error"? A (simple) example to illustrate the difference would be great!
3
votes
1answer
639 views

Are nominal attributes strict classifications and equivalent to enumerations in programming languages?

I've been looking random forest algorithms for text classification and referencing the Mahout random forest decision tree description. In it, there is a reference to two types of variables, nominal ...
2
votes
3answers
2k views

Degrees of freedom for Chi-squared test

I am facing the following dilemma. I am aware of how to handle the one-sided Chi-distribution, but I am falling victim to how to handle degrees of freedom. Let me clarify with an example what I mean. ...
9
votes
4answers
646 views

Difference between the terms 'joint distribution' and 'multivariate distribution'?

I am writing about using a 'joint probability distribution' for an audience that would be more likely to understand 'multivariate distribution' so I am considering using the later. However, I do not ...
33
votes
8answers
3k views

Rigorous definition of an outlier?

People often talk about dealing with outliers in statistics. The thing that bothers me about this is that, as far as I can tell, the definition of an outlier is completely subjective. For example, ...
42
votes
7answers
4k views

What, precisely, is a confidence interval?

I know roughly and informally what a confidence interval is. However, I can't seem to wrap my head around one rather important detail: According to Wikipedia: A confidence interval does not ...
40
votes
4answers
35k views

What is the difference between fixed effect, random effect and mixed effect models?

In simple terms, how would you explain (perhaps with simple examples) the difference between fixed effect, random effect and mixed effect models?
2
votes
3answers
1k views

Calculation of incidence rate for epidemiological study — prevalence rate this time

Thanks for all the answer for the question Calculation of incidence rate for epidemiological study in hospital. And here come's the second part of the question: What about the prevalence rate then? I ...
4
votes
3answers
6k views

Calculation of incidence rate for epidemiological study in hospital

I have kinda puzzled when I heard from the other about the calculation of incidence rate From Kenneth Rothman's Modern Epidemiology, the incidence rate is calculated as ...
9
votes
6answers
34k views

What is the difference between effectiveness and efficacy in determining the benefit of therapy 'A' on condition 'B'?

The context of this question is within a health framework i.e. looking at one or more therapies in the treatment of a condition. It appears that even well respected researchers confuse the terms ...