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An easy and intuitive approach is cross-validation. Tell the managers you built the model on a longer time frame, say, the sales data from time 2010 to 2015. Then show them the real sales of 2016 (e.g …

A recent CNN/ORC national telephone poll of US citizens for presidential elections has resulted in the following propotion estimates $\hat{p}$ of votes by likely voters for Clinton (C), Trump (T), and …

I conduct 30 independent significance tests on $p<.05$. I observe that in $X=3$ cases the test is rejected. Can this event be caused by chance due to a multiple testing problem? I understand that $X$ …

In your case the "confounding" does not matter. Your within-subject / repeated measures data collection design comes in as a fortune. In your problem we define $W=X-Y$, so you are interested in testin …

I am reading an article from Statistics in Medicine ("Tutorial in biostatistics: multiple hypothesis testing in genomics"). For my question it is only relevant to know that $V$ denote the number of fa …

Some immediate responses: 1) Your lecturer means that the data show autocorrelation. This leads to inefficient estimates of regression coefficients in simple linear regression. Depending on whether i …

The central question is whether you assigned students completely at random to the experimental groups. If yes you can use a standard test for independent samples to assess the significance of the gr …

In a Bayesian setting and given data $D$ I want to test the hypothesis that $$H_0: \theta_2 \le \theta_1$$ against alternative $H_1: \theta_2 > \theta_1$. Assume I can only sample from the posterior …

Suppose you have two null hypothesis for two parameters, $\theta_1$ and $\theta_2$ based on the same variable $X$. So for example, $\theta_1$ is mean of $X$ in group 1, whereas $\theta_2$ is mean of $ …

I think you really want to test $H_0: p=.5$, where $p$ is the proportion of people answering. An easy way to get your hands on that problem is to get the confidence interval for the proportion estimat …

In analogy to a similar post on continuous data, I ask the following. In paired discrete data, we test the frequentist hypothesis of equivalent marginal distributions of two discrete variables $X$ and …

Which options are there to test, whether two contingency tables of the same variables, say $X$ and $Y$, are equal across the levels of a third discrete variable, say $Z$? I can think of a log-linear …

I just read in a rather well-respected (popular) science magazine (the German PM, 02/2013, p.36) about an interesting experiment (without a source, unfortunately). It caught my attention because intui …

A/B tests that simply test repeatedly on the same data with a fixed type-1 error ($\alpha$) level are fundamentally flawed. There are at least two reasons why this is so. First, the repeated tests are …