Skip to main content
Search type Search syntax
Tags [tag]
Exact "words here"
Author user:1234
user:me (yours)
Score score:3 (3+)
score:0 (none)
Answers answers:3 (3+)
answers:0 (none)
isaccepted:yes
hasaccepted:no
inquestion:1234
Views views:250
Code code:"if (foo != bar)"
Sections title:apples
body:"apples oranges"
URL url:"*.example.com"
Saves in:saves
Status closed:yes
duplicate:no
migrated:no
wiki:no
Types is:question
is:answer
Exclude -[tag]
-apples
For more details on advanced search visit our help page
Results tagged with
Search options not deleted user 2488

Hypothesis testing assesses whether data are inconsistent with a given hypothesis (usually a null hypothesis of no effect).

2 votes
0 answers
381 views

Converting a chi2 to a sigma value

I am working in astronomy. I fit a theoretical model to some data. The model takes input parameters (like the mass and age) and produces some outputs that I compare with the data. I measured the goodn …
rhombidodecahedron's user avatar
1 vote
1 answer
73 views

Sampling from the null distribution for a t-test

I am trying to apply the Dietterich 5x2 cv t-test to test whether one statistical model is better than another on a particular data set. In order to apply this test, one must assume that under the n …
rhombidodecahedron's user avatar
2 votes
0 answers
199 views

Paired non-parametric test for a difference in variance

I have $N = 391$ paired data points $\mathbf a = a_1, \ldots a_N$ and $\mathbf b = b_1, \ldots b_N$. Both $\mathbf a$ and $\mathbf b$ are approximately normally distributed with a mean of zero. I …
rhombidodecahedron's user avatar
2 votes
1 answer
437 views

Hypothesis testing with regression models

I have two regression models: a linear model with one variable, and a neural network with many. I want to test whether the neural network is better than the linear model. I am wondering the best way …
rhombidodecahedron's user avatar
2 votes
1 answer
2k views

Dietterich's 5x2cv paired t-test for regression problems

In 1998 Dietterich proposed an algorithm for comparing classification algorithms using a series of cross validated t-tests: Dietterich, Thomas G. "Approximate statistical tests for comparing supervi …
rhombidodecahedron's user avatar
1 vote
1 answer
2k views

Statistical test for the difference in mean for two normal distributions

I have measured $x$ and $y$ and estimated their uncertainty. They are both distributed normally. I found $x = 5 \pm 0.25$ and $y = 7 \pm 0.5$. I want to know if these estimates are statistically dif …
rhombidodecahedron's user avatar
3 votes
2 answers
100 views

Assessing significance when measurements are correlated

I am trying to estimate a function $f(x)$ at $x=0.1, 0.2, 0.3, 0.4, 0.5$. I make this estimate through some complex procedure based on a set of independent but noisy data (with known uncertainties). …
rhombidodecahedron's user avatar
1 vote
0 answers
46 views

Does the $\chi^2$ test of variance rely on homoskedasticity? [closed]

I have a linear model $y=ax+b$. I have fit the relations using two data sets. I have found that estimate of $a$ from the two data sets are similar, but that the uncertainty of $a$ is much larger in on …
rhombidodecahedron's user avatar
0 votes
0 answers
46 views

Showing that an increase in uncertainty is significant

I have a linear model $y = ax+b$ and I estimate the coefficients $a$ and $b$ in the ordinary way. I have found out that all of my values of $x$ were systematically overestimated, and also that they …
rhombidodecahedron's user avatar
1 vote
0 answers
33 views

Testing if slopes differ using data with different uncertainties?

I have two data sets that each have the following form: x y sigma 13 1495.00 0.07 15 1700.91 0.09 ... basically where $x$ and $y$ are given, but also the uncertainty of $y$, denoted $\sigm …
rhombidodecahedron's user avatar
1 vote
1 answer
90 views

How to show whether the average coefficients of determination from one regression technique ...

I have 50,000 objects on which I have performed two different types of regression. Using cross validation, I obtained the average $R^2$ score from each model on each of the objects. So now I have a li …
rhombidodecahedron's user avatar
3 votes
1 answer
83 views

What does "(scores mapped into 1:m using rounded scores)" from the 1-sample permutation test...

I'm trying to do an exact paired permutation test. What does this "mapping" mean? > library(exactRankTests) > perm.test(rnorm(10), rnorm(10), paired=TRUE, exact=TRUE) 1-sample Permutation Test ( …
rhombidodecahedron's user avatar
2 votes
2 answers
111 views

Obtaining error bars for a difference

I have a pair of data sets, and I want to know whether the medians of these two sets differ significantly. I've calculated the median of each set and subtracted them from each other. How can I determi …
rhombidodecahedron's user avatar