# Tagged Questions

Rejecting the null hypothesis when it is true.

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### A strange finding with the logrank test statistics

When I try to confirm the type I error rate of the logrank test by simulation, I found something strange... Firstly, I generated 100 observations from exponential distribution with lamda1=1 as group 1 ...
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### Heteroskedasticity and Type I, Type II Error

If one is conducting a hypothesis test for heteroskedasticity, would one generally consider a Type I or a Type II error more serious? What is the reasoning behind this?
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### How to calculate FAR & FRR from Confusion Matrix?

For a biometric authentication system, I'm trying to compute the False Acceptance Rate (FAR) and False Rejection Rate (FRR) from the confusion matrix generated in Weka. I am using SVM with 10-folds ...
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### Is alpha error inflation a problem with multiple ordered logistic regressions?

Following problem: I'm doing a survey where my independent variables are: (1) the perceived attractiveness of a product on a 7-Likert-scale and (2) the willingness to invest in such a product as a ...
53 views

### Why would you want a smaller critical region when testing large samples?

Is it because when you have a smaller critical region you have a smaller probability of the event happening?
37 views

### Significance level in sample size calculation and in final analysis

Imagine that for the purpose of a study a sample size is computed with the following formula for a given power $1-\beta$, difference in means $\epsilon$, standard deviation $\sigma$ and significance ...
10 views

### type 1 and type 2 errors for non-normal residuals in a regression

I did a regression and performed a normality tests on my residuals, which reject the Null Hypothesis that the residuals are normally distributed (the true distribution seems to be flatter with fatter ...
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### Is there a concern for multiple comparisons when ranking instead of using significance?

Let's say I have many ANOVA tests on the same data using different factor variables each time. Then, I want to rank the F-statistics for all of those tests. Notice that I'm not interested in ...
194 views

### Type 1 and Type 2 Errors

A fabric manufacturer believes that the proportion of orders for raw material arriving late is p =0 .6. If a random sample of 10 orders shows that 3 or fewer arrived late, the hypothesis that p =0 .6 ...
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### Second type error for difference in proportions test

I want to calculate the second type error Beta for a difference in proportions test, in a two populations scenario. Google search guides me to different tutorials to perform the test of proportions, ...
44 views

### Checking stability of a model in relation to experiment-wise error rate (philosophical)

I recently read an article that included a checklist aimed at improving the reporting of results in psychology. Among other things, they made the following suggestions: If observations are ...
76 views

### Confidence Bands vs. Simultaneous Confidence Intervals

This may be a dumb question, but when talking about multiple regression analyses are "simultaneous" confidence intervals and confidence "bands" the same thing? I'm still having trouble figuring this ...
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### Estimating the false positive rate for a strictly standardized mean difference

Does anyone have a good source that clearly explains how to estimate the false positive rate or restricted false positive rate of the strictly standardized mean difference (SSMD)? I am trying to ...
240 views

### Does false discovery rate depend on the p-value or only on the alpha level?

Let's say I get a p-value of 0.001. I know that alpha level dictates the probability of a type I error, so if I get a result this significant, is my false discovery rate (FDR) lower than if I were to ...
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### Dependence, independence, multiple testing, and alpha error correction

although I have studied psychology and feel I should know a lot more about issues such as this one, I have a quite basic question (or maybe not so basic question, considering all the fuss about this) ...
117 views

### Correcting for family-wise error rate with series of repeated measures ANOVA?

I am trying to make requested revisions to an accepted manuscript, and I am baffled by the following comment from a reviewer: "Eight hypothesis tests are reported in the final paragraph of the ...
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### What is the name for this unintuitive result with OLS on a very “asymmetric” regressand, and how should it be addressed?

Say our sample consists of about a hundred Belgian (x = 0) and Swiss (x = 1) chocolate bars. We test them to see if they have safe (y = 1) or lethal (y = 0) levels of arsenic. As it turn out, 90% are ...
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### Does N-1 correction for Pearson's Chi-Square apply to r x c tables generally?

Campbell (2007) recommended what he called the "N-1" correction for chi-square tests performed on two-by-two contingency tables. He described the correction as: "the K. Pearson chi-squared test ...
405 views

### Low sample size: LR vs F - test

Some of you might have read this nice paper: O’Hara RB, Kotze DJ (2010) Do not log-transform count data. Methods in Ecology and Evolution 1:118–122. klick. Currently I am comparing negative binomial ...
299 views

### What is the basis of setting critical p-value value in stepwise regression?

In statistical software like MINITAB and SAS, the default alpha value (critical p-value) is set as 0.15. I would like to know (1) if there is any statistic basis to set it as 0.15 and (2) if this is a ...
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### error summary metric

I am working on trying to get a summary metric that summarizes the results of four models (M1:M5) and preferably ranges from zero to one, with one being the best model and zero being the worst model. ...
108 views

### Simulating violations of regression assumptions

I'm wondering if anyone could provide some code (preferably in R) which demonstrates violated assumptions leading to type 1 errors. Some concrete examples of errors arising from assumption violations ...
338 views

### Negative-binomial GLM vs. log-transforming for count data: increased Type I error rate

Some of you might have read this nice paper: O’Hara RB, Kotze DJ (2010) Do not log-transform count data. Methods in Ecology and Evolution 1:118–122. klick. In my field of research (ecotoxicology) we'...
2k views

### Is the “hybrid” between Fisher and Neyman-Pearson approaches to statistical testing really an “incoherent mishmash”?

There exists a certain school of thought according to which the most widespread approach to statistical testing is a "hybrid" between two approaches: that of Fisher and that of Neyman-Pearson; these ...
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### Why am I getting a 10-15% type I error rate for a 2 x 2 ANOVA?

While testing type I error rate using R, I found that I am getting higher than 5% false positives with a 2-way ANOVA. However, I thought one of the reasons for using an ANOVA (as opposed to multiple ...
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### Critical region for difference in proportions

A new virus breaks out on a cruise ship. I want to test the hypothesis that males and females are equally likely to contract the virus. I am going to test 100 men and 100 women. Presumably if I find ...
I was checking on Type I (reject a true H$_{0}$) and Type II (fail to reject a false H$_{0}$) errors during hypothesis testing and got to to know the definitions. But I was looking for where and how ...