Questions tagged [differences]

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2answers
45 views

Summary statistics for two populations

I have two populations: part-time worker in the health industry (IND=17) and part-time worker in the financial industry (IND=12) For those two populations I have several variables (demographic ...
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0answers
16 views

How can I separate the abundance factor of the incidence results?

I must calculate the incidence values for Watermelon Mosaic Virus in different seasons within of habitat. This incidence data comes from infection detection of some plant sampled in different habitats ...
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0answers
42 views

Is there a word in statistics for “mean divided by absolute difference”?

For two values, let's say a and b, I calculate a mean of two numbers divided by absolute difference between them. i.e. ...
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0answers
17 views

Difference of two independent lognormal random variables by Fourier transform methods?

Is it possible to calculate the difference $X_1-X_2$ of two independent lognormal variables $X_1$ and $X_2$ where $\log(X_1)\sim N(\mu_1,\sigma_1)$ and $\log(X_2)\sim N(\mu_2,\sigma_2)$? Could I ...
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0answers
22 views

Problem with differencing trend-stationary processes?

I have read somewhere (possibly in Hayashi's Econometrics text) that it can be problematic to work with differenced trend-stationary processes. I have not been able to find the exact source again and ...
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1answer
11 views

Get predicted (leveled) value of y from a differenced regression in time series

Suppose I have two time series variables (x and y) which have unit root (non-stationary). I would like to regress y against x, but because they are non-stationary, I first stationarized them by ...
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0answers
3 views

Proportion difference - measuring effect size

This question is related to What statistical method should I use (not chi square) **Some of the subjects may be in multiple groups. I would like to know the proportion between the scores and how ...
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6answers
615 views

What is the difference between econometrics and statistics?

It's never been very clear to me what distinguishes econometrics from statistics. My preliminary understanding was that statistics is data-focused whereas econometrics always starts from theory. But ...
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0answers
10 views

How to pull in-sample fitted models towards out-of-sample optimum during training?

A common problem in prediction problems is getting a model fit on in-sample data to predict out-of-sample data with decent accuracy and precision. Assuming that we break a part of the in-sample data ...
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1answer
19 views

What statistical method should I use (not chi square)

I have data which represents numbers of population in 3 different categories (I'll call them A,B and C). The y axis represents different scores (1-20 in total). Example: ...
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0answers
25 views

What is the expectation of absolute difference

Given: E(|X-R|) =2.5 E(|L-X|)= 3 where X, R, L are assumed to be normally distributed and independent. Standard deviations of |X-R| and |L-X| are known. what is E(|L-R|) ?
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1answer
34 views

t-Test for dependent samples for z-standardized values?

I've got children's questionnaire scores (mean of 6 items) regarding a particular variable (here: how well the child likes to interact with technology), and a score of the same child by a parent (they ...
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1answer
71 views

Levenshtein Distance vs Damerau Levenstein vs Optimal String Alignment Distance

Could anyone explain in simple words (and maybe with an example) what the difference between the Levenshtein Distance, Damerau Levenstein, and Optimal String Alignment Distance? When would one use one ...
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0answers
24 views

How to moderate a change score?

I am using STATA to perform linear regression. Here is the analysis I would like to perform: I have weight measured at Time 1 and Time 2 (continuous variable). I have fatigue measured at Time 1 and ...
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1answer
28 views

What probability distribution do you fit to 'differences' between percentages (can take both negative and positive values)?

I have some data about fisheries and there is a variable which denotes differences between two percentages and hence has both negative and positive values. I want to run a model with this as a ...
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1answer
44 views

What is the difference between Spectral Clustering and Laplacian Eigenmaps?

It seems like Spectral Clustering is just a term for dimension reduction via Laplacian Eigenmaps + a clustering algorithm on the output. Is this the case, or am I missing some fundamental difference?
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3answers
44 views

Is a time trend a substitute for first differencing?

I am doing a macroeconomic analysis involving BOP, investment ratio, GDP growth rates, and CPI inflation as dependent variables. My independent variables are other macro variables. When I test for ...
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0answers
18 views

How can I compare differences between geometric means?

Background: The HDI (Human Development Index) is a geometric mean based on 3 variables (each normalized to a value between 0-1). There is a fair description of the details here. I copy below the ...
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0answers
15 views

Why in SAS proc glm, the SE of a difference just simply takes on the larger SE of the two means in comparison?

In SAS proc glm (simple one-way ANOVA), I noticed the SE of differences do not correspond to widely circulated uncertainty propagation technique (e.g. any variation of quadrature summation, pooled ...
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0answers
19 views

Differential Item Functioning with Autistic and control samples

I'm carrying out a DIF analysis of a self-report questionnaire which measures 'systemising', or the drive to construct/understand complex systems such as technology/maths/buildings/etc, to check for ...
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0answers
12 views

Working with difference time series and reconstruction

I have a time series of length 33. Upon taking the second difference, it is reduced to a stationary series. The acf and pacf plots indicate an order (3,3). I tried various models around (3,3) and ...
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0answers
11 views

Analysis of statistical differences between two data sets

I would appreciate if you could suggest what tests (on STATA) I could use to check the following: I have data from the world bank on BMI in a certain country (nationwide); I went on a field to collect ...
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0answers
26 views

Difference order distribution of extremal values of two uniform sequences

Fix an integer $m$. Pick two random integer sequences ($a_1$ to $a_n$ and $b_1$ to $b_{n'}$) uniformly independently from $[1,m]$. Denote $a(i)$ to be $i$th smallest value of $a$ and $b(j)$ to be $j$...
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0answers
47 views

Distribution of order statistics from the same sample? Distribution of difference betwen order stats

Suppose we have $i$-th and $j$-th order statistics from a sample of i.i.d. random variables. How to derive the difference between these order statistics? For example, it's obvious that, if $j>i$, ...
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0answers
28 views

If the dependent and independent variables are not stationary, but they are first difference stationary. Can I use the original variable?

If the dependent and independent variables are not stationary, but they are the first difference stationary. Can I use the original variable?. If I use the percentage change for the dependent and ...
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0answers
15 views

Concise clear explanation Confidence Intervals for Differences & Sums

I understand confidence intervals for means and proportions, but just don't see how it works for differences and sums. I don't even fully understand its purpose or why I should care. I've seen two ...
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0answers
31 views

Calculating interclass correlation but with different observer experience

I have tried finding an answer to the following question both here and using PubMed and google but without luck. I have been asked to calculate the intraclass correlation coefficient from the ...
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1answer
21 views

Summing up differences of means

Say I have four treatments with two factors: Treatment 1: Factor A Treatment 2: Factor B Treatment 3: Factor A and B Treatment 4: no factor (Control) I can now use anova to detect interactions. I ...
0
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1answer
38 views

Model selection based on the closest fit to another model

For each subject I have two measures, let's say $X$ and $Y$, that correspond to the same measurement but each from a different measurement device. In theory we assume that ideally these two ...
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1answer
79 views

Statistical test for preference data through average differences or is other method more suitable?

I need your help. I'm designing a questionary and there I want test which version the people prefere. Which of the following methods is better and which statistical test for significance in each ...
2
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1answer
291 views

derivative of mathematical expectation [closed]

As we know,if x is a random variable, we could write mathematical expectation based on cumulative distribution function $(F)$ as follow: $E(X)=\int[1-F(x)]d(x) $ In my problem, t is a random variable ...
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2answers
29 views

Comparing Closeness Between Two Counts

I need to count the number of cells in several pictures. Since the picture is not totally clear, I let two people to count for each picture. I need to compare to see if the two counts are close enough ...
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0answers
176 views

Probability that one positive random variable is greater than another independent and identically distributed positive random variable

Suppose I have the following random variables $X_{0} \sim f(x)$ and $X_{1} \sim f(x)$ are independent. I want to know the probability that $X_{0} > X_{1}$. So I think I want to find: $$ P(X_{0}>...
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0answers
10 views

properties of the disurbance term ε in the difference regression

let's say we a model $$Y_t = β_1 + β_2X_t +u_t$$ assume that u's are in fact serially independent, and that $u_t= ρu_{t-1} + ε_t$ what are the properties of the disturbance term $ε$, if we used the ...
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0answers
52 views

Is the difference between two samples of two distributions a sample of the difference of the distributions? [closed]

My question is as follows. Suppose you have two variables $X$, $Y$. If I pick a random sample $x$ from the distribution over $X$ that has probability density function $f_X$, and another random sample $...
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0answers
19 views

Comparing predictability of outcomes across leagues

From time to time I encounter newspaper articles with titles like “Unpredictable English Premier League Keeps Us Guessing”, which make claims about the difference in predictability of outcomes across ...
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1answer
41 views

Why do I get completely different results when subjecting my data to a t-test in different ways?

I subjected my data to a t-test in two manners of which I expected the same output would be generated. It turned out it is not so. Now I would like to know wherein the profound differences in the data-...
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1answer
19 views

Two formulas giving slightly different output

I am struggling to find a proper explanation why the two methods that I use for finding the difference in EXCEL are giving me two slightly different numbers. The idea behind the task is that we have ...
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0answers
95 views

Are Box-Cox and differencing redundant or complementary?

I was always under the impression that differencing and Box-Cox were two ways to achieve the same goal: Making a time series stationary so that it can be modeled using an ARMA process. However, ...
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0answers
122 views

When to choose difference versus log ratio for expressing variables relatively?

Oftentimes I wish to express one time series (say) relative to a second one. The two obvious candidate approaches are to take their difference or their ratio. Whereas the difference is symmetric with ...
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1answer
70 views

What is the relation between the effect size and correlation?

Correlation refers to the degree to which a pair of variables is linearly related. The effect size quantifies some difference between two groups (e.g. the difference between the means of two datasets)....
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0answers
22 views

Subtraction between features before performing PCA and training a classification model

In my dataset, I've created moving averages for historical indicators. Is it pertinent to perform subtraction between those moving averages before PCA? My stats/calculus feeling: as PCA is a ...
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0answers
190 views

How to interpret Emmeans results

I have used the emmeans() package to calculated the difference between the difference of estimated marginal means. I did this by first calculating the EMMs of location|treatment, and then the ...
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0answers
23 views

First or second difference or log for simulated real GDP data?

For a paper I need to use simulated real GDP data to regress this on average income mobility (how much more the next generation earns). As a hint the assignment indicates that the STATA code for a ...
5
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1answer
557 views

What is the relation between ELBO and SGVB?

Evidence lower bound (ELBO) can be maximized, so that to find the most appropriate approximative distribution of the target distribution, which is equivalent to the minimization of the corresponding ...
2
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1answer
200 views

What is the difference between belief propagation and loopy belief propagation?

Belief propagation (BP) is an algorithm (or a family of algorithms) that can be used to perform inference on graphical models (e.g. a Bayesian network). BP can produce exact results on cycle-free ...
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0answers
33 views

What is the difference between “paired” and “unpaired” versions in Wilcoxon's test?

Statistical tests can e.g. be used to decide whether to accept, reject or fail to reject the null hypothesis (the status quo). There are (apparently) two variants of this Wilcoxon's test: paired and ...
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0answers
16 views

Method to compare difference in average treatment effect between 2 subgroups and then between two study arms? Difference in differences for RCT data?

Essentially I have an RCT with 1 intervention arm and 1 control arm. Within each arm I have 2 sub-groups I want to compare the average treatment effect (drug users and non-drug users) for a binary ...
1
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1answer
16 views

Compare the progression in multiple groups with different starting points

I am working on a project where 8 municipalities have participated in a program, in which they received consultancy on how to restructure the social sector. As a part of the program the municipalities ...
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0answers
25 views

Two-dimensional difference test

Suppose I need to find out whether both the average height and the average weight of a person in two populations are the same. Is there a standard extension of the difference test in two dimensions? ...