The independence tag has no wiki summary.
0
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2answers
32 views
Parallelization of an iterative model
What I have:
An iterative process based on the application of a very simple algebra to represent a rate, with total dependence among any iteration and its predecessor (one input parameter for (n)th ...
3
votes
1answer
53 views
Independence of samples
Recently I started doing verification on daily temperature forecasts by different providers. I calculated the absolute forecast errors for each of the providers, and I am planning on performing ANOVA ...
2
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1answer
36 views
How to prove independentness of marginal/conditional (?) posterior distributions?
This is a question about exercises 4.2 and 4.3 of Jim Albert’s “Bayesian Comptutation With R” (p. 82). Note that while this might be homework, in my case it is not.
We are to prove that, given two ...
3
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1answer
63 views
Optimal approach to independence check
I want to see if a vendor is biased against one type of vehicle compared to another.
I have two categories of vehicles: OWN and T/C.
The vendor sells fuel to these vehicles.
The process is as ...
1
vote
0answers
30 views
Using the dependent variable as part of a control variable?
I'm regressing on a variable where its ratio with another variable is meaningful in itself. Both are also quite skewed, so I would like to log the ratio so that I have $Y = \beta_0+\beta_1 X_1 ...
1
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0answers
15 views
Log-linear analysis vs Breslow-day test
I would like to test independence of several categorical variables for a few datasets. I believe Breslow-day is possible for some of the analyses I want to do, and log-linear may be possible for all, ...
1
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0answers
31 views
How to find the connection between variables
Assume that you want to approximate your joint distribution on set of variables via decomposing it into several smaller distributions. Assume that you don't know any prior knowledge about the ...
2
votes
1answer
40 views
Is there a function to check a set of events/random variables are mutually independent?
Say, 5 random variables A,B,C,D,E which can take values either 0 or 1.
I have the theoretical population chances for the 32 cases of P(A,B,C,D,E). Obviously they add up to 1.
How to check if ...
1
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0answers
57 views
Are the angles between iid training data and the classifier learned from them independent?
Suppose I have a training set $\mathcal{T}^N = \{(x_i , y_i) \in \mathbb{R}^{d} \times \{0,1\}\}$, where the data are i.i.d draws from some distribution.
Now I learn a classifier $\hat{h}$ from these ...
2
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0answers
44 views
Apparent fallacy in Fisher-Irwin test
For a hypothesis $H_0\equiv p_1=p_2$ (for two Bernoulli distributions), we take a measurement and find that $X_1=i,X_2=j$, and we denote $k=i+j$
Now, to test $H_0$, the Fisher-Irwin test tells us to ...
0
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0answers
28 views
Non-significant results
I conducted a between-subjects study and all my results were non-significant.
Now, for a repeated measures I know you go into Mauchlys when reporting, but since my study
isn't a repeated measures but ...
1
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0answers
10 views
Is dependence of one classification on another a violation of the assumption of independence for ANOVA?
My subjects are mice, swimming in a pool for 60 s. The DV is how much time they spend in each quadrant of the pool. The performance of each subject is independent of every other subject. However, ...
2
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1answer
29 views
How does randomization testing for correlating two variables work?
I was going through OpenIntro Statistics[http://www.openintro.org/stat/textbook.php] and came across two case studies in the first chapter
Discrimination against women during promotion - Page 42
...
0
votes
1answer
92 views
Alternative nonparametric test for chi-square test for independence
suppose we have a table like this:
\begin{array}{ |l | c | r |}
\hline
& \mathrm{win} & \mathrm{lose} \\ \hline
\mathrm{male} & X_{11} & X_{12} \\ \hline
...
0
votes
0answers
16 views
Why is the CDF of the maximum of two random variables their respective CDF's multiplied? [duplicate]
I have the following random variables:
X = uniform over [0, 1]
Y = uniform over [0, 1]
Z = max{X, Y}
(X and Y are independent)
I don't understand why the CDF of ...
0
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0answers
80 views
What test of independence of sample proportions is appropriate when n is very large and p is very small?
I have the (not necessarily veridical) impression that typical textbook independence tests of proportions are intended for use the proportions involved are not super small.
In my case n may be 10^8 ...
1
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2answers
85 views
Constant hazard in survival analysis and random event occurence
I read that in survival analysis, when the hazard function $$\lambda(t)=\underset { dt\rightarrow 0 }{ lim } \frac { Pr(t\le T<t+dt|T\ge t) }{ dt } =c$$ then the event occurrence is random and ...
2
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2answers
77 views
Does independence imply conditional independence?
If two or more variables A, B, C, etc. are jointly mutually independent of one another, does this imply that that they are also conditionally independent given some set of conditioning variables X, Y, ...
6
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4answers
332 views
Is winning a soccer match independent of previous wins\losses?
$\quad$ I have a friend of mine who is a bit of a gambler ask me this question. He is of poor mathematical background, but has a sense of logic and will probably accept a logical answer in the natural ...
1
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0answers
32 views
Does the independence assumption interact with the generalizability of results in hierarchical designs?
A friend recently posed to me the following problem:
Is it possible to do a Chi-square on test results for a group of participants to determine if they made more of type A errors or type B errors?
I ...
3
votes
1answer
98 views
Level of analysis and assumption of independence in Pearson Chi-square test
I have survey data about injuries occurring to athletes over the span of their careers. Many of the athletes suffered multiple injuries (the most any athlete reported was five and this did not occur ...
1
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2answers
155 views
Principal components analysis: how independent should the input measures be?
I have a waveform, for which most people will measure either a peak amplitude or a slope. I have included the area under the curve and several other measures involving the same original waveform. I ...
1
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1answer
56 views
Benefit in getting Orthogonal dimensions from a data set
What are the benefits of getting a new data set in which all their dimensions are independent from an original data set (applying PCA)?
we know we can reduce the storage space needed, speed up ...
4
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1answer
138 views
Summarising significance tests for multiple independent variables
Having recently run an experiment, I have been left with a dataset that I don't quite know how best to handle, I think simply due to the number of independent variables to consider.
Setup
I have ...
2
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0answers
60 views
How to show independence and interpret the result
If $X$ is symmetrically distributed about zero , then show that $U=|X|$ and
$$V = \left\{
\begin{array}{}
+1, & X \geq0 \\
-1, & X<0
\end{array}
...
3
votes
2answers
173 views
What is the difference between using the multiplication rule or using Venn diagram subtraction for probability?
Take two problems:
Andrew is 35, and the probability he will be alive in 10 years is .72. Ellen is 35, for her, .92. Assuming these are independent, what is the probability they both will be alive ...
1
vote
1answer
141 views
How to test for serial correlation of a time series itself (not residuals)?
We know that Ljung-Box test can be used to test for the residuals of a fitted model. But to test for the serial correlation of a time series itself, is there a way to do that?
2
votes
1answer
128 views
How to get conditional variance from Schur complement?
Suppose you have vectors X and Y with covariance matrix
$V = \left( \begin{array}{cc}
A & B \\
B^T & C \end{array} \right)$. This Wikipedia article says that $Var(X | Y) = A - BC^{-1}B^T$, ...
1
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1answer
88 views
Unequal, independent repeated measures analysis
I have an agricultural ditch that was converted to a different geometry in 2002. I have one year of measured cross-section data on the ditch before construction. I have 3 years of measured ...
1
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3answers
108 views
Probability of independent events given the history
I am having some trouble understanding something that feels very basic in probability theory concerning the past history of repeated independent events.
Consider the tossing of a fair coin. ...
2
votes
2answers
82 views
Statistical independence of combining random samples
Given a single finite population of size N, if I obtain S random samples from the data (replacing after each one), and randomly partition these into 2 sets of S/2 random samples, can I treat these two ...
8
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1answer
255 views
Does the multivariate Central Limit Theorem (CLT) hold when variables exhibit perfect contemporaneous dependence?
The title sums up my question, but for clarity consider the following simple example. Let $X_i \overset{iid}{\backsim} \mathcal{N}(0, 1)$, $i = 1, ..., n$. Define:
\begin{equation}
S_n = \frac{1}{n} ...
1
vote
2answers
98 views
Independence test for values between 0 and 1
I want to compare a set of frequencies and determine the p-value of their dependence. One of them is the null distribution of frequencies and the other is the distribution that I want to test. The ...
1
vote
1answer
48 views
Independence over time
I have some categorical data from a clinic taken over a year long time period. The plan is to perform a Pearson's Chi Squared test (of independence) on this data.
I am extracting data from a clinic's ...
3
votes
1answer
181 views
Experimentially proving that random variables are independent
I just had a very simple (possibly very dumb) question.
How would I, experimentally prove that two random variables drawn either from the same population or two different populations are independent ...
2
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1answer
123 views
Independence of mutually exclusive dummies in same regression?
I have been wondering about this for a while. When I have mutually exclusive dummies in the same regression, are their coefficients independent?
For example, suppose I have the following:
...
1
vote
1answer
200 views
Independence of errors assumption in paired & independent samples t-test
first of all, this is a great site and I've already learned a lot from threads here wile searching for answers to my stats questions on the web. Yet here's another one:
I understand that the ...
3
votes
1answer
171 views
I want to know how independent two variables are
I have no formal training in statistics so please correct me if I use the wrong terms as I try to explain my problem.
I have a set of data (less than 80 points) with essentially 1 single outcome (a ...
1
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0answers
51 views
Methods for sampling mutual independent and k-wise independent random variables
I wonder how a sequence of mutually independent random variables
(each with a different or same distribution) is sampled? In other
words, how can a sequence of values be ensured to be samples of a
...
0
votes
1answer
52 views
Independence of Random Variables
I was just wondering:
If the joint distribution of $X$ and $Y$ is independent with $Z$, does it imply that $X$ and $Z$ are independent as well?
Can anyone give a counterexample/proof?
2
votes
0answers
113 views
How to implement a regression with non-independent observations in the DV?
I have a design where a number of object pairs were rated for association strength. These pairwise association ratings along 5 criteria of interest are expected to be used as IVs in a regression.
...
4
votes
1answer
223 views
How to report results of Fisher's test for larger than 2 by 2 tables
This is probably a very easy question but what is an acceptable phrase for reporting a Fisher's test where the number of rows and the number of columns are both $>2$. An example in R:
...
16
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2answers
316 views
Independence of residuals in a computer-based experiment/simulation?
I conducted a computer-based assessment of different methods of fitting a particular type of model used in the palaeo sciences. I had a large-ish training set and so I randomly (stratified random ...
1
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0answers
58 views
Independence of a single sample? [closed]
Is it possible to speak of the independence of a single sample (of multiple data points) relative to the underlying distribution? Or is independence only relevant between samples?
3
votes
1answer
87 views
Showing independence
$X_{1}$ and $X_{2}$ are independent, chi-square distributed random variables. I've managed to show that $Z=X_{1}+X_{2}$ is independent of $\frac{X_{1}}{Z}$. How do I conclude then that $Z=X_{1}+X_{2}$ ...
1
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2answers
85 views
Independence in a sum relationship
I have a model of total reaction time T, which is a composite of a selection time S and a discrimination time D. So a person first finds something, this takes the tS. Then he discriminates and reports ...
2
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0answers
33 views
Should two equal pseudo-random numbers in a sample count as a “run down” or a “run up” in a runs test?
Taking into consideration the runs test proposed by Knuth given a sample of pseudo-random numbers to test independence, and looking at this example:
...
1
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2answers
169 views
Uncorrelatedness implies independence under some condition?
How would I go about proving the following statement:
Given two random variables, $X$ and $Y$,
if $E(h(X)g(Y)) = E(h(X))E(g(Y))$ for all bounded and continuous $h$ and $g$,
then $X$ and $Y$ are ...
1
vote
1answer
98 views
Are the products of different independent random variables independent?
I'm confused about the independence of the product of independent random variables.
Let A and B be independent of each other ...
2
votes
1answer
112 views
Independence test with some aggregation
I have a bunch of data consisting of pairs (i,j), with both i and j drawn from the same set S of size k. I would like to do an independence test similar to a chi-square test.
However, I don't care ...
