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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Can I use K-S statistic to determine best fit even when the null hypothesis is rejected?

I'm comparing data from two different models, I also have the real data. I want to demonstrate that one model fits the real data distribution better than the other model. Unfortunately none of the ...
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Test to see if differences between measurements are different across groups

Here's a simplified version of my problem. I asked two people to guess the height of people walking by. The guesses were very different. I learned that sometimes estimators would sit and sometimes ...
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How to do normality test for high dimension data?

I have samples from a $d$ dimensional distribution $p$. The distribution of $p$ is unknown. I want to use the samples to judge whether or not the $p$ is close to a standard unit Gaussian distribution. ...
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What is the difference between Consistency and Identification?

Dear experienced friends, I start to learn Econometrics recently and there is a question really confuses me. Suppose we have a sample linear model $$ y = \beta*X. $$ From the definition, we know the ...
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How do I determine the efficacy of a ranking metric?

I have a dataset where I am attempting to perform a classification task. At present only 15% of the data is a positive class. I believe with some feature engineering I've been able to generate a ...
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66 views

A/B test sample size formula confusion

I was trying to understand the math behind some commonly used calculators and formulas for A/B tests and it seems that there might be some variations. Ideally, I would like to understand how each of ...
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Should our claim ever be the null hypothesis?

I recently read the following regarding the null and alternative hypotheses: If the original claim includes equality $\left(\le, =, \text{or} \ge\right)$, it is the null hypothesis. If the original ...
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Split data into test, training and validation when some patients have multiple observations

I have a dataset that has multiple observations for some patients. Patients are labelled by patient IDs and I would like to split the data into testing, training and validating groups as I am trying ...
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Is it preferable to subset data to test specific hypotheses or specify a full model and run contrasts?

Let's say I have a 2x2 design where participants are either in condition A or condition B and, within each condition, either get exposed to exposure C or exposure D. First, I want to test whether ...
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Proving Neyman-Pearson by Cases

In the proof of Neyman-Pearson from, Let $ \pi _0,\pi _1 $ be two populations with probability distributions say $ f_0,f_1 $ (with measure $ \mu $ ). Then for testing $ H_0:f=f_0 $ against $ H_1:f=...
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How would I compare a set of discrete data before and after treatment?

What type of statistical test would you use to examine the difference in these tests to see if there is a difference between the before and after sample? Treatment A results Grade 8 Grade 9 Grade 10 ...
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How to prove statistical significance, python

I'm new in statistics and would be so grateful if you give me some insights: I have two big tables - results of work Model_1 and Model_2. I created and calculated statistics - something like Precision ...
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How can I test if two groups of products have very close cumulative revenue whenever time period I observe them?

So I have two groups of products with different sizes and each group has a different group of products in it. I created these groups by ensuring that the difference between these two groups’ ...
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Testing a hypothesis involving ranks with an unequality in the null hypothesis

Here's a toy example of the problem I'm dealing with I have gene expression data from two patients' multiple tissues ...
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Implementing permutation tests in randomized controlled trials with repeated measures

I am trying to implement a permutation test to use for testing treatment effects in a repeated measures RCT-design. Unfortunately I am having some trouble understanding how to design a correct ...
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What statistical test should I use with count data? [duplicate]

In my experiment, participants are shown 4 images (A, B, C, D) that they have to rate on a 5 point scale. So my data looks like this: particpant1: A 5, B 3, C 3, D 1 p2: A 4, B 3, C 2, D 4 p3: A 4, B ...
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Alternatives of permutation test to proof that a model performs better than chance level

I built a model based on a very high dimensional data, which requires 4-5 days to built using High Performance Computing (HPC). I want to do a statistical test to proof that the predictive power of my ...
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Why is the probability of a type 1 error, $\alpha$, the significance level?

I've seen this stated Why are p-values uniformly distributed under the null hypothesis? and https://support.minitab.com/en-us/minitab-express/1/help-and-how-to/basic-statistics/inference/supporting-...
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Categorical ordinal data: which test is better? [closed]

I have the following data: Group very bad bad quite good good very good A 12 20 11 29 14 B 20 10 6 11 34 Group A receives training, group B doesn't which test is appropriate for this kind of data?...
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Evaluate the increase of a variable (in Likert scale) for a subgroup of the population in a poll

Let's say we do a poll/survey for $n=250$ people, and we study a variable in a Likert scale with 7 possible values (-3 to +3): ...
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Designing an experiment to compare how multiple SMOTE variants affect multiple classification models on multiple datasets

For a university paper I want to test a hypothesis that one particular SMOTE variant outperforms two other SMOTE variants. By 'outperforms' I'm looking at using the F1 measure. I want to test this ...
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Statistical test for comparing performance metrics of two regression models on a *single* validation dataset?

What is an appropriate way to apply a statistical hypothesis test for evaluating model performance metrics (e.g. MAE, MAPE, MSE) between two regression models based on a single holdout (validation) ...
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Durbin vs. Breusch-Godfrey test for autocorrelation: which is better?

I'm being asked to justify why I use either the Durbin's alternative test for Serial Correlation or the Breusch-Godfrey test. It seems that both are relatively competent tests however there is little ...
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Is this a valid method to test textual difference?

For some research I am trying to reject/ not-reject the null-hypothesis that the proportion of a word is higher in a certain sample of a text than in the rest of the text. The full text is a ...
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Appropriate ways of analyzing the influence of two independent variables on a reaction time?

I have the following experimental data. The dependent variable is a reaction time which has been measured on n = 30 test subjects. The reaction time was measured six times per test subject and the ...
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What's the z-test of the compare column proportion in spss tells us?

I have two categorical variable - 1.Status - what is the occupation of the customer. 2. loyal - if a customer is loyal or not And I am trying to do hypothesis testing. My null hypothesis is that there ...
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Hypothesis testing with time autocorrelated data

I have a dataset such as the following: ...
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How to manually calculate the p-value of a t-test arising from a hypothesis test on the coefficient of a linear regression model?

Suppose we have a linear regression model $$ Y = \beta_0+\beta_1X + \epsilon $$ and wished to test $H_0 : \beta_1 = 0$ vs $H_1 : \beta_1 > 0$. How can I explicitly write out the form of the p-value ...
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What are the minimum and maximum values for the Type-I and Type-II error probabilities of a hypothesis test?

My professor asked this question in a video lecture recently and said it should be something we could "derive" on our own. However, I'm having a hard time wrapping my head around the ...
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What-If Scenario Regression Modelling

I'm pondering a scenario involving some insurance data but this could be relevant in many fields. The idea is that I have a total count of some event. Let's imagine this count is the # of attorney ...
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Formulating the null hypothesis when the depended variable is a ratio involving the independent variable

I face the following simple regression model: $$ \widehat{rdexp}=\hat{\beta}_{0}+\hat{\beta}_{1}log(sales) $$ where $$ \widehat{rdexp}=\frac{RD}{sales} $$ and $RD$ is some positive number. I am having ...
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Statistical test to examine multiple attributes' effect on an outcome

I want to compare different attributes of a population and see if one is more indicative of an outcome measurement than the other. In a general case, suppose I want to examine $k$ attributes. Each ...
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Statistically compare accuracy of several CNNs | data independence & k-fold crossvalidation

I want to set up several CNNs, give them different input data (e.g. an nDSM or an orthomosaic) and then test if the runtimes and the accuracies are significantly different from each other. How can I ...
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Intuitive understanding of hypothesis testing with Z-scores

I wanted to dig a bit deeper into hypothesis testing and fresh up my conceptual understanding from undergraduate courses. The typical way of how hypothesis testing is teached is to calculate the Z-...
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Find the decision boundary in bernoulli distribution

I encountered this question but I find some obstacles to convert this problem into a t-test format, can you guys give me some hint? Thanks! Your local casino acquires some new slot machines, which the ...
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How to test the null hypothesis that two linear regression lines have the same Y value for a particular X value?

I am using ancova to test if two linear regression models are the same and it works great. I am following this tutorial: http://www.biostathandbook.com/ancova.html and I apply it in R with this ...
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Best test to use for investigating if the difference between means is significant?

I'm studying the length of stay for patients in a hospital. I have a sample of n=4533 observations. Each of these observations are assigned to an admin group numbered between 1 and 8, based on the ...
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Is this log-log plot that is produced in SPSS sufficient to PH?

How do you graphically test proportional hazard assumption in Cox regression in SPSS? Should I put the variable in the "block" or "Strata" in SPSS? This log-log plot is produced in ...
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Is it statistically valid to perform two linear regressions to approximate a test for a U-shaped distribution?

Consider a sample dataset with a putative U-shaped distribution. I want to test whether the U-shaped relationship is statistically significant. Specifically, if y signficantly decreases as a function ...
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What test statistic for the hypothesis that early events affect future events?

Consider you observe a series of events occurring over time where an event's time is denoted by $t_i$ ($i=1,2,...$). That is, you observe a vector $t = (t_1, t_2, ..., t_k)$ for $k$ events. Your ...
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How to measure the effect of a group without individual information over time

I would like to hear your thoughts on how to test the following effect. A group of n people is recorded performing a specific task. Each recording is rated between 0 - 30 (30 being best). After having ...
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Which assumptions should be checked for regression tree to validated model?

I am working with regression tree. I have four predictors. There is a exponential relationship between predictor and dependent variable. But after building predictive model I cannot understand whether ...
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What is the minimum number of samples that you need per group in a Western blot in order to perform a hypothesis test?

I am doing Western blot data analysis and I have 2 groups of values. I want to perform a statistical test to compare the means of the two groups to see if there is a significant difference. I am ...
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Comparison of 12 measurements in 2019 and 12 measurements in 2020 of the number of individuals in a facility. What is the best method?

I need to compare attendance measurements within the same facility, taken each last day of the month in the year 2019 and the year 2020. So I have 12 measurements in 2019 e 12 measurements in 2020. ...
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Appropriate Statistical Test for Likert Data?

I am having trouble deciding the appropriate statistical test to use for a given experiment. In the study, participants first recorded various feelings on a 4 point Likert scale. Ex: How much do you ...
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implementation of $\chi^2$ test in python

I'm trying to check if a set of data has a Poisson distribution and for that I'm trying to implement a chi square test. My input data is an array that counts the amount of events registered in 1 ...
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Determine observed t from 2 means from set of values

"A study was conducted to compare the costs of supporting a family of four Canadians for a year in different foreign cities. The lifestyle of living in Canada on an annual income of 75,000 ...
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Paired Hypothesis Testing with Conversion Samples

Let's assume I have 100s of websites on which I am tracking conversion. At some point I change something to all websites. I want to measure if there is a statistical significant difference between my ...
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How to perform this test for the fairness of a coin?

Suppose the task is to test whether a coin is fair (i.e. has equal probabilities of producing a head or a tail). If the coin is flipped 100 times and the results are recorded, the raw data can be ...
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How to carry out the hypothesis test in this example from wikipedia?

This is an excerpt from the wikipedia article on test statistics: Suppose the task is to test whether a coin is fair (i.e. has equal probabilities of producing a head or a tail). If the coin is ...