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Hypothesis testing assesses whether data are inconsistent with a given hypothesis rather than being an effect of random fluctuations.

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Sample size calculation for multiple hypotheses testing on two or more metrics

Let's say I want to run an experiment where there's a control and there's a feature group (say, 50-50 random split). The treatment can affect the feature group in 1, 2 or three ways (or any ...
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Can I use bootstrapping technique to get a 95% conf. interval of conversion rate

I have a sample data about user conversion at an ecommerce site. The data contains the following variables: User Id Site visits - count of the number of times the user visited the site during the ...
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1answer
25 views

How do I evaluate the increase/decrease in a set of test scores between two groups?

I have two groups of students, one group who received tutoring, the other who did not. I have the test scores for both groups in the beginning of the year (Mark1). I also have their test scores at ...
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1answer
18 views

Test for significant differences in two groups of binomial data

In a study per-field disease incidences were collected by sampling 35 plants in each field and counting proportion of infected ones (# of infected/total sampled). In result, each sampling location ...
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1answer
23 views

Hypothesis Testing - Switch hypothesis and get same result?

Beginner to hypothesis testing. Have removed/replaced terminology, but these samples are from real-world populations doing a specific real world action where whichever option they picked splits them (...
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11 views

To find the "Most Powerful Test (MP test) of the given hypothesis problem

A friend of mine asked me the question below on testing. My approach: I tried to solve this sum using Neyman-Pearson Lemma( NP Lemma ). But I am not sure if I'm correct. Please help me and let me ...
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What should my critical region look like in this LR test for shifted exponential distribution with pdf $e^{-(x-\theta)}\mathbf1_{x>\theta}$?

I have a small confusion over describing the cutoff point for the critical region in a likelihood ratio test when the null hypothesis is composite. Take this exercise in particular: Let $(X_1,X_2,\...
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p-value, literature request for the notion of p-value,statistical hypotheses testing [duplicate]

I would like to know the name of a statistics textbook in which the notion of $p$-value is treated as detailed as possible.An Amazon link will help.Thank you.
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30 views

Basic likelihood ratio test

I should perform a likelihood ratio test on the following null hypothesis : α = Aψ where α and A (p * m) are known vectors. ψ (m*r) is a matrix of free parameters. The likelihood ratio test is ...
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1answer
17 views

Formal interpretation of likelihood ratio tests?

The following is a hypothetical question and I don't have a specific model in mind... Consider two models $M_0, M_1$ such that $M_0$ is nested within $M_1$. I perform the likelihood ratio test with $...
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21 views

Choose between several confidence interval procedures for randomization test

I am trying to produce confidence intervals for a randomization test of no effect and I've found two different methods in the literature. I have a hard time comparing the two and selecting the best ...
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1answer
12 views

How to find false negative rate when there are multiple alternate Hypothesis?

I am testing for zero Pearson correlation and my null hypothesis is $\rho=0$. It is easy to find Type 1 error or rejection of Null hypothesis and hence the false positive rate. However, my ...
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How to validate if partitions of a training set have been generated by the same joint distribution?

Following Luxburg (2008) in a supervised learning problem: We do not make specific assumptions on the spaces $X$ or $Y$, but we do make an assumption on the mechanism which generates those training ...
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21 views

Is the R function wilcox.test only useful if samples have same variance?

I have two samples of observations drawn from distributions with different variances. To test whether they have the same mean, I plan to use the function wilcox.test...
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6 views

Statistical distribution of randomly-selected distances

As part of a complicated project relating to widgets being sent out to incorrect factories ("missorts"), I am examining a process which involves operators standing on a conveyor belt, removing widgets ...
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0answers
10 views

Testing that's there's no difference in conversion testing

I am looking at implementing a new website A/B testing tool. Before I turn everything over to it, I want to run a test where I divert traffic to two experiences that are exactly the same and show they ...
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3answers
129 views
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How do I prove one company is actually doing better than another?

Suppose I have the return information for two reverse logistic companies--See example data. For certain groups companies A and B each receive 50% of the work from a client, but for another group ...
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1answer
26 views

How to get posterior probability from Bayes factor

I ran into this question in my class and am not sure how to solve it: A positive test result gives you a Bayes factor of 71 in favor of being sick. If your prior probability of Being sick was 0.05, ...
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34 views

Finding the most powerful test concerning picking balls from an urn

Suppose that an urn contains $6$ balls in all, of $\theta$ different colors, with an equal number of balls of each color, where $\theta\in\Theta ={\{2,3}\}$. (a) Letting $X$ be the number of ...
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1answer
24 views

Mismatch on T value obtained from t.test vs summary(lm(data)) on R

I'm doing an exercise on R about the hypothesis testing and I have the following data: ...
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1answer
37 views

Number of samples and Statistical Power

I know that as size of the sample $N$ increases, the $Z$ value increases. But as the $Z$ value increases, that means the $p$ value must decrease. So what happens to $\alpha$ If we had set it to $.05$...
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Recommended significance test for coefficients in regression mixture with bootstrap Standard errors?

I have fit a model that comprises of a mixture of regressions. Within each regression I have an estimate of the coefficient of each covariate within that component regression. The model was fit using ...
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17 views

Wilcoxon Signed Rank Test in Python (Reporting Siegel's T vs W?)

While using the Wilcoxon signed rank test in scypy over a subset of populations, I noticed that my test score was reported as zero for an array of differences whose distribution of medians is heavily ...
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2answers
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What's the right stats test?

Could anyone tell me what would be a suitable stats test to look at relationships between 4 continuous IVs and 1 continuous DV between 2 groups each of which has 2 levels i.e. male - female and ...
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21 views

Comparing groups? Wilcoxon, Paired test?

I am carrying out a simulation experiment where a fixed number of resources are, at the end of the simulation, divided between two groups of individuals, 'A' and 'B'. There may or may not be the same ...
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12 views

Correct group of factorial and repeated-measure ANOVA

I'm currently having trouble defining what type of ANOVA I need to run as well as how to run it correctly. This is the following setup: I have 4 groups of 30 people doing a 2-session task (one after ...
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1answer
37 views

Why do we divide by the degree of freedom?

This might be trivial and vague question, but I still don't understand why when creating test statistics or estimators we always divide by the degree of freedom. Just to give examples of what I'm ...
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4answers
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Does a uniform distribution of many p-values give statistical evidence that H0 is true?

A single statistical test can give evidence that the null hypothesis (H0) is false and therefore the alternative hypothesis (H1) is true. But it cannot be used to show that H0 is true because failure ...
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2answers
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Validity of t-test, Welch's t-test and Mann-Whitney U test

Suppose you wanted to compare whether the returns of stocks A and B had the same mean. It is unlikely they have the same variance. To do this you performed a t-test, Welch's t-test and Mann-Whitney U ...
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Error when xgboost result is applied on test set [closed]

After running xgboost on the train set, I apply it on the test set and get this error: xgbpred1 <- predict (xgb1,dtest) Error in predict.xgb.Booster(xgb1, dtest) : Feature names stored in object ...
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1answer
38 views

Hypothesis Testing - When to use which test

Does anyone know of a good, reliable website that lists the hypothesis tests (for population mean, population proportion, difference of means - I am in a first year stats course) along with their ...
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14 views

Any AI/ML approaches for analysis of competing hypotheses?

I know there are significant development about sentiment analysis in text e.g. "x is awful", "x is bad" or "y is fantastic". But are there similar approaches to compare hypotheses? e.g. given a ...
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15 views

Likelihood Ratio Given Conditionals

For each person, I have at least one report indicating whether they have a disease or not. I have the actual disease status of a decent chunk of this population, and I'd like to be able to predict ...
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How to calculate Standard Deviation in weighted Paired t-test?

I'm attempting to figure out the formula for a weighted & paired t-test. For reference, I want to know the weighted equivalent of R's...
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1answer
26 views

My deep learning model works with Stratified K-Fold, but not in predicting future time events

I have a project at work where I'm supposed to predict a specific location given cell phone signal parameters. I developed a deep learning model that uses convolutional neural network on time-ordered ...
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1answer
25 views

Which coeffcients are used for a F-statistic

I have an F-statistic, $F(4,10)$, my constant and 4 Coefficients $\beta_2 , \beta_3 , \beta_4$ and $\beta_5$ I already know that the (in this case) 10 reflects the number of obsverations. But what ...
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2answers
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Actual meaning of anova table

I am having trouble understanding this simple example form the book Applied Survival Analysis in R. The example is as follows, Consider three cox models Model A only contains ageGroup Model B only ...
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Comparing two independent groups that follow a power-law

I have two independent samples that each follows a power law distribution. I want to investigate whether the average of one of the samples is greater than the average of the other sample. Which ...
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Estimating population means for two independent normal samples

My questions is as follows: If I have two random samples from two independent normal populations with common unknown variance, how could I estimate the population means using a bayesian model? The ...
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Possible questions on testing on hypothesis in A/B testing for a position of a data scientist (EDITED)

What are some possible machine learning and statistics questions on the subject of A/B testing for a position of a data scientist in Ad Tech industry working in retargeting? I'm interviewing for such ...
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22 views

Should I use dependent t-test or independent t-test

I have a software that produces a sentiment score between 0 and 1 given an input sentence. I want to test if this system produces biased scores based on the gender of the subject used in the sentence. ...
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19 views

Can linear ballistic accumulator (LBA) models be used for hypothesis testing?

The linear ballistic accumulator (LBA) provides a useful means of modelling participants' performance on forced choice tasks. It gives some very informative metrics of response behavior with respect ...
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Permutation and multiple testing - permuting the test labels instead of sample labels?

I'm comparing $m$ p-values, where $m$ is very large. Every p-value comes from a two-sample $t$-test of two groups of size $n_1$ and $n_2$, where the $n_i$ are very small ($2$ or $3$). This leads to a $...
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1answer
36 views

Compare two discrete distributions using Chi-Sq

(I am not quite sure whether the following post is better suited for CrossValidated or for StackOverflow because I have both a theoretical question about the use of the Chi-Squared test and a more ...
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1answer
27 views

Analysis of impact between 2 observations

I have 2 columns of ~18000 observations. First column contains a value that shows the delay of a filed document (in days) of year 2017. For example: if the document had to be filed on May 5th 2017, ...
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10 views

Statistical difference between time values.

I am comparing the activity onset times of a bat species across different sites. I have the onset time values for 5 different sites for a period of one month. I want to check if the activity onset is ...
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29 views

Conditional expectation function of linear regression including hypothesis testing

I'm currently trying to solve a problem set, specifically exercise b) below. I quickly state the whole problem for clarification: Suppose you want to test whether in your country women are ...
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Problem of multiple testing when checking the assumptions of a particular test

I have two sets of measures and I'd like to check whether the two samples come from the populations with the equal means. In order to choose the right test, I should first check a few things, such as: ...
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1answer
45 views

In how many cases my H0 is passed?

For a weekly jury duty there are 50 places for men, and women. The probability of choosing a man, or a woman is equal to 0.5. ...
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2answers
124 views

How do I compare means when I have a sample and the whole population?

I have the following didactical exercise to carry out: Scenario I have the avg room price for all the hotels of my chain (32 observations of the 32 hotels). Then I have the avg room price for a ...