# Questions tagged [f-test]

Any hypothesis test in which the statistic has an F distribution under the null hypothesis.

96 questions
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### F-test to determine whether more than two sets of data differ

Here is the context for my question: I understand that you can fit the same model to two different datasets separately and then fit the model to the datasets pooled together as a way to discern ...
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### When to use likelihood ratio test vs. incremental F-test in nested nonlinear model selection?

I have two nested nonlinear models and I want to know which provides a better fit to some data. I see descriptions of both the likelihood ratio test and of the incremental F-test (also called the ...
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### When to use F-Test versus Chi-Square Test in Analysis of Deviance

I'm choosing a GAM, and when I try to do anova(model.1, model.2, test="F") It gives me a warning message saying that the F test is inappropriate for binary ...
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### Unbiased hypothesis tests

Is there some textbook or expository account showing that the definition of "unbiased test" bears the same sort of relation to "unbiased estimator" that interval estimation generally bears to ...
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### R - Testing for Granger causality when OLS assumption are violated

I am using the vars package to estimate a VAR-model. Since it seems, that the residuals of my model are neither homoscedastic or uncorrelated I computed Newey West ...
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### How would I test to see if a data set is described by a specified (not calculated) 2nd order polynomial line?

In Short: Given a set of data and a specified 2nd order polynomial trend line, how can I go about testing a hypothesis that the line describes the data? I'm not asking to do a linear regression on ...
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### How is the F-test superior to the $\chi^2$-test for handling overdispersion?

I am interested in analyzing data from group randomized trials: a group randomized trial involves recruiting groups, like children within a school, people within a community dwelling, bats in a cave, ...
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### Testing simultaneous equality of contrasts

I have a one-way ANOVA model with 3 treatments. I have contrasts $\hat{\theta}_1=\hat{\mu}_1+\hat{\mu}_2$ and $\hat{\theta}_2=\hat{\mu}_3-\frac{1}{2}(\hat{\mu}_1+\hat{\mu}_2)$. I want to do a ...
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### Double clustered standard errors and degrees of freedom in Wald-style F test for joint significance of regression coefficients with panel data

In panel regression, the Wald-style F test for joint significance of the regression coefficients is usually done with an adjustment for the degrees of freedom when robust/clustered standard errors are ...
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### Confused about F-contrast and F-test in statistical software

Let's say I have an estimated parameter $\beta$ from a general linear model for 2 subject groups (with the $\beta$s corresponding to their means). If I wanted to do a two sample t test in a ...
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### Interpreting numerator of an F-statistic

"the numerator expresses a measure of squared distance standardized by the covariance matrix" That is the author's interpretation on page 97 in Introduction to Linear Regression Analysis by ...
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### When is non-normality severe enough to warrant using different tests?

I've been doing quite a bit of reading on the topic of non-normality, and how it pertains to the F-test. My understanding is that non-normality tests aren't very useful, as outlined in the arguments ...
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### How would I determine statistical significance for ad impressions?

I'm programatically adding keywords to bid on. Some keywords will trigger ads and impressions, and some impressions will trigger clicks. Clicks / impressions = CTR (click-through-rate). Clicks cost. ...
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### model comparison: chi2 vs. AIC (and BIC)

I've been using the approach from Appendix A from this paper. It states that if I have two fits with $\chi^2$ values $\chi^2_1(\nu_1)$ and $\chi^2_2(\nu_2)$ ($\nu$ - degree of freedom), then their ...
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### Test fixed effects for joint significance in R

Just as in this post I'm looking to test for the joint significance of the fixed effects in a model. Unlike the post I referred to, I'm looking to test each fixed effect individually. I have used a ...
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### Test the difference between average value of 2 random variables

I am doing an exercise on marketing analysis to determine the strategy that a brand should follow based on historical weekly data collected from supermarkets that sell the brand (let say brand1) and 4 ...
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### Is this an appropriate way to compare simulated and measured data with small sample size, and are there alternatives?

I have a probably fairly basic question which I couldn't find an answer to on here or anywhere else. Would really appreciate any thoughts on this :) I am modelling the propagation of sound through a ...
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### Deriving the F-test for a complex comparison

I would like to clarify a passage from Maxwell & Delaney, Ch.4 Extension in which the authors explain how to perform an F-test for a complex comparison. In what follows, the coefficients $c_j$ ...