Questions tagged [hypothesis-testing]
Hypothesis testing assesses whether data are inconsistent with a given hypothesis rather than being an effect of random fluctuations.
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Which hypothesis test should I Use? Help pls
I'm doing a personal project and would like to see if High Caloric Food has a statistical significance on Weight Level. I've tried Chi Squared Contingency test as suggested by chatgpt but it gives a p-...
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using standardized residuals from a previous chi-square analysis as an IV in a regression
I have an analysis I'm considering, and I'm not familiar enough with the statistical details to tell if there are any potential errors. I've done my best to describe the analysis briefly below.
I ...
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Statistical test for multiple measurements per participant where each participant is subject to the influencing variable
The goal of our study is to test whether migraine patients use their phone differently (e.g., spend less time on their phone) during headache periods compared to non-headache periods. We monitored ...
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How to do hypothesis testing for Minimum value?
I have a sample with a size of n=100, and I want to show that the minimum value of the underlying distribution is not less than a certain threshold, with a confidence level of 95%.
The distribution of ...
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Are p-values computed from the a priori or a posteriori sampling distribution?
Wikipedia defines a p-value as follows:
the p-value is the probability of obtaining test results at least as extreme as the result actually observed, under the assumption that the null hypothesis is ...
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Error when trying to perform repeated measures ANOVA in R [migrated]
Consider this data frame:
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Different results between ANOVA and Linear Mixed Effects
A set of subjects from two groups are requested to perform a test after a sleep session of type A and then after a sleep session of type ...
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Alternative test instead of logistic regression for binary dependent outcome variables?
I have a dataset of patients who underwent an operation, and I collected information on post-surgery complications such as necrosis (binary outcome variable). Now, I would like to investigate whether ...
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Confusion about replication in ANOVA [closed]
Set Up
It's about finding out which formulation (concentration in percentage) and soaking time of formulation yields to a better measured outcome.
In the table below, Minutes represent soaking time ...
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Dealing with many positive-depenent insiginicant results in Benjamini-Hochberg-procedure [closed]
I'm dealing with a statistical problem, where I tested a bunch of hypotheses with a very strong positive dependence within certain groups of them. Many of them didn't lead to significant results.
Now, ...
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Hypothesis tests for Rayleigh variables
Given samples from two Rayleigh-distributed random variables with unknown parameters, $X \sim R(\sigma_x), Y \sim R(\sigma_y)$, what tests can we use to determine if and to what extent their ...
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Finding P-value and power of the Most Powerful Test
You observe a sample $X_1, \quad, X_{20}$ with the density
$$
f(x, \vartheta)=2\left(x / \vartheta^2\right) I_{[0 \leq x<\vartheta]}
$$
with an unknown parameter $\vartheta>0$, yielding
$$
\min \...
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Interpretation of Statistical Tests and the Importance of Statistical Power [duplicate]
I was planning on running a statistical test for hypothesis testing, but was confused if statistical power is important once a test is run.
Looking at this confusion matrix, one would ideally set ...
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Difficulty understanding Chi-Squared p-values in this case
Forgive me, but I'm new to this. I have two columns of categorical data. The data represents access to a particular resource, where a 1 indicates that the individual accessed the resource and a 0 ...
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Multiple goodness of fit tests for multinomial proportions of unbalanced classes
I am considering a case where I have a nominal variable with $L$ levels (let us say $L=2$ for simplicity) and a bunch of continuous features. I would like to test if the most centrally located point ...
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Is this a good statistical approach for evaluating process change effectiveness?
I'm working on a project where I need to evaluate the effectiveness of process changes in a production environment. I've used both traditional null hypothesis testing and Bayesian analysis for this ...
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What standard references discuss the differences between hypothesis testing, estimation and prediction? [closed]
I am trying to understand the ramifications of this three-way distinction, particularly when it comes to model building. Could someone point me at the standard references on the subject?
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Are post-hoc adjusted analyses more valid than initial analyses?
Many papers design a methodology to detect a difference between $2$ groups regarding a primary outcome. This result is then given a $p$ value to denote statistical significance. Some papers then go on ...
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What is the best statistical test for percentage of respondents data?
My data consists of three columns
A is the percentage of those who answered 'Yes' on question 1
B is the percentage of those who answered 'Yes' on question 2
C is a number that represents a score. ...
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UMP two sided tests for exponential families
Consider a random variable $X$ with density $$f(x : θ) = C(θ)e^{η(θ)T(x)}h(x), θ ∈ Θ$$.
Assume that $η(θ)$ is strictly increasing in $θ$ and that the family is full rank. Show that there will not be ...
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What test should be used for two non-independent groups of different N?
This is my first question so apologies for any problems with it.
I am carrying out an experiment which involved counting the number of people using the stairs or the elevator during a 30 minute period,...
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How to analyse a non-inferiority trial using GEE in R?
I'm trying to analyse a non-inferiority trial in R. Since there are correlated observations and a population averaged interpretation seems fine, I want to use GEE.
To illustrate my problem, I will use ...
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Hypothesis test on binary preference
I have two product designs and I want to see if there is a significant difference between which people like which design the best. I did a survey where I showed a photo of each design and asked ...
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A suggestion for a statistical test or Model to Prove the regression results
I am working with the following dataset. (I attached a screenshot of some of my data):
Data name is HTO and has the following variables $x$ and $y$, pre- and post-test, and the delta ($\Delta$) ...
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Can you combine sequential testing with the Benjamini-Hochberg/Benjamini-Yekutieli procedure
I am trying to avoid large amounts of type-1 errors in the evaluation of multiple hypotheses within the same online A/B test. Currently, features are tested across different platforms, with several ...
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Difference between F-test and confidence intervals on variance estimates
Given n samples from a normally-distributed variable X, we estimate variance as $s^2=\frac{1}{n-1}\sum{(x_i - \bar{x})^2}$. We can also get a confidence interval for such a variance estimate as:
$$...
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How to test if occurrence distributions are equal with dependent variables
Description of the experiment
Each experiment is a performance done by an artist/athlete, and these are independent.
I have $k=4$ judges labelled $J\in \{1,2,3,4\}$ that can classify a performance ...
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Test Distribution Difference between small sample sizes
My first post of StackExchange.
I am working on data analysis project for comparison of fraud and nonfraud transactions. My objective is to compare the feature vectors of nonfraud transactions and ...
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Hypothesis testing of normal distribution, unknown mean unknown variance
Suppose that we make measurements of an effect, and we know that the values that we obtain follow a normal distribution. But we don't know the mean nor the variance. The hypothesis is that 95% of the ...
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Am I able to compare pooled AUC values (from a meta-analysis) of two similar tests conducted in the same samples to establish which may be superior? [closed]
I'm new to all of this so I apologise in advance.
I'm currently conducting a meta-analysis and have pooled AUCs that represent the accuracy of two very similar prognostic factors in predicting ...
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Wilcoxon test on distribution derived from bootstrapping
We have two Chocolate bags X and Y. Each chocolate bags have total 1000000 chocolate boxes randomly sampled from 100 types of chocolate boxes (B1, B2, …, B100). These chocolate boxes are of different ...
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Paired t-test on dependent samples
I have a set of paired observations, corresponding to patient blood pressure before and after a treatment. I'd like to test for the significance of the treatment by conducting a paired t-test (or ...
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How do I obtain a one-tailed p-value for Games-Howell's test (as calculated by most R functions)?
I am trying to understand:
1 - why p-value is calculated as it is in Games Howell test, and
2 - how to modify an R function to obtain a one-sided (alternative: greater) p-value for the test
When it ...
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Regression coefficient before vs. after demeaning X
It is well known that $\beta = (X^{T}X)^{-1}X^{T}Y$ for linear regression. While experimenting with this, I found that $\beta$ (excluding the intercept term) remained the same before and after ...
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Comparing the mean of biological replicates that are not normally distributed, low N for replicates
I work in cell biology where the field standard is now to do 3 biological replicates of experiments. However, each data point is extremely laborious to get and we receive very little statistics ...
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Different conclusion from confidence interval and NHST
I would like to ask. I gave to students an example where they test :
$H_0: \pi=0.65$
$Ha: \pi>0.65$
$\hat{p}= 0.76$
$n=50$
Students have to calculate NHST and also confidence interval for ...
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One sided Wilcoxon test
I want to check whether a training program made an improvement on knowledge level on participants.
I applied a test before and after the training to the same people (this means I have 2-samples, ...
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The statistical power decreases as the time point change in the data increases [closed]
Let $X_1,\dots,X_n$ the data generated by the signal plus noise model having a change in mean at $\tau\in\Pi=[t_1,1-t_1],\;0<t_1<1$, which defined by:
$$\begin{cases} X_t=\rho_0+\varepsilon_t,\;...
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How do I determine sample size when the conversion rate for the null hypothesis is not deterministic?
I use a ML model to rank prospects in terms of purchase probability to send marketing emails on a monthly basis. Most of the people in the population (for example, the entire U.S population) would not ...
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How to test belonging of value to distribution defined by set of samples
I have a set of $\{X_i\}^N_1$ observations. Under assumption that they all come from unknown distribution $D$, what is the statistical test for observation $Y$ (one value) to belong to the same ...
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How to find the correct sample size for a non parametric hypotheis test
I have two independent population data with each having 500 K rows. The goal is to perform a hypothesis test and test the claim that the new machine takes less time than the old machine. This 500 K ...
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Why isn't Random walk with trend non-stationary according to ADF?
A random walk with trend doesn't have unit root. So, null hypothesis will be rejected. Hence, according to alternative hypothesis, since it doesn't have unit root, it will become stationary process as ...
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Hypothesis Testing - Varying p-value issue in my MWU
I have two machines (A & B) in our production line. A is older, B is very new. Both perform the same tasks, except that machine B is advanced and will perform 1 task less than the no of tasks in ...
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What is the best method for imputing binary (or integral/count) data?
I have a longitudinal dataset, and I want to create a composite score by including five healthy lifestyles to measure the overall lifestyle over time (use as predictor). Each lifestyle is a binary ...
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What is the information in an exact p-value?
Consider the following two statistical principles: 1) an exact test's $p$-value gives the exact frequency with which the observed random sample appears by chance, i.e., under a true null hypothesis; ...
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Can I add more than 2 independent groups to an Ancova and if so, do I need to create dummy variables in SPSS
I want to analyze the difference between 4 groups on one dependent variable while controlling for my covariate, age, and 3 different independent variables (sex, cancer type, metastasis) in SPSS. Can I ...
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What's the power of the following Hypothesis test?
This is a question I got on my recent intro-stats exam which I still can't comprehend.
"What's the power of a hypothesis test with significance level 0.05, if the probability of picking 5 or more ...
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What are some tests for paired data with replicates?
Suppose I have $m$ cultures of each of two strains of bacteria. I subject each culture of bacteria to different growth conditions, and measure the cell viability at the end of the experiment. This ...
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Bayesian hypothesis testing using posterior samples of estimated parameter
I'm modeling recruitment curves using a Hierarchical Bayesian model. There is a key parameter in my recruitment curve, let's call it $P$. I have two groups (A and B) of participants of respective size ...
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Nonparametric test (akin to a sign test?) for multiple interacting effects across multiple conditions
Problem
I have $K$ sets of conditions (index by $k\in\{1,..,K\}$), and each set has $N_k$ conditions. For example, if $K=2$ and $N_1=N_2=2$, we could call the conditions (A,B) and (C,D).
I have ...
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