All Questions
Tagged with hypothesis-testing distributions
444 questions
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Updating a Continuous CDF After Observing Realised Draw From Same CDF
I am trying to solve for some updated distributions, but having a little trouble conceptualizing what I am doing.
In particular, suppose I have two CDFs, say $U[0,0.8]$ and $U[0.2,1]$; call them $...
0
votes
1
answer
113
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Reliable method for hypothesis testing on zero-inflated continuous data
I'm testing impact of a new flow on website sales performance. It is pretty straightforward to test impact on
conversion rate (number of sessions ending with transaction divided by total number of ...
- 120
0
votes
1
answer
39
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Compare the frequency of records
I have records such as:
\begin{array}{}
\hline
\textrm{2024-07-27 21:52:39} \\
\textrm{2024-07-27 21:54:15} \\
\textrm{...} \\
\textrm{2024-07-28 21:58:44} \\
\textrm{2024-07-28 22:01:15} \\
\textrm{.....
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1
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1
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53
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Appropriate significance test for small sample size, unclear (non-normal) distribution
Given data:
30 datapoints in the form of usability scores (System Usability Scale)
2 groups within data (Group 1: 17, group 2: 13, independent, unequal sizes)
Objective:
See if there is any ...
- 123
1
vote
3
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78
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How to show that many functions (a hundred, a thousand) have the same shape an distribution of values over an interval?
I have functions that on iterval [0,1] all seem to look like this:
i.e. they have a zero around 0.4 +ve derivative from zero to 0.4 and around zero or slightly negative derivative up to 1.
I plan to ...
- 13
2
votes
1
answer
69
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How can I show statistically that one of my replicates is likely contaminated?
I have a dataset that looks like the below: five replicate samples, each of which is composed of 4 different fractions that sum to 100%. The fifth sample clearly looks visually distinct from the other ...
- 288
1
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0
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36
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Method to compare two latency measurement groups
I have two measurement (or rather two or more sets of measurements) of server software (DNS).
The measurement results does not have normal distribution, they are very skewed towards 0-1 milisecond ...
- 111
1
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0
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42
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Statistical test to check if two samples come from the same DISCRETE distribution
I am computing hourly backward wind trajectories for the 1985-2023 period, and obtaining all the pixels that are crossed by these trajectories. I have the pixel ID frequencies for these trajectories - ...
- 11
5
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4
answers
193
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Distribution of $Z^2 \cdot I(Z > 0)$ where $Z \sim \text{N}(0,1)$
When using the Likelihood Ratio test for testing particular hypotheses and attempting to obtain an size-$\alpha$ test, I run into the expression
$$ \mathbb{P}\left( Z^2 \cdot I(Z > 0) > c \right)...
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1
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54
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Conditional Probability of the null hypothesis given the rejection region
let $X \sim Bin(10,p)$
We would like to test the following hypotheses:
$H_{0}: p=0.5 $ vs $H_{1} : p=0.3$
The Statistic $T(x)$ is defined as $T(x)=x$ and the critical (rejection) region is $R=\{x:T(...
- 11
4
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1
answer
49
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How to estimate required sample size for the two-sample Kolmogorov-Smirnov test
I have a simulation model which produces a value for an output variable. Running it many times gives skewed distributions for this output variable. What I'd like to do is compare two distributions, ...
- 151
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0
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13
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How to compare peak location and tail length of two different distributions?
I have the distributions of the fraction of people in each income bracket in a town in 1990 and 2020. The total sample size is the same in both, and assume that the incomes have been adjusted to ...
2
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0
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127
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Comparing two p-value distributions and obtaining aggregate significance and effect size
PROBLEM DESCRIPTION
My data is a population of entities. Each entity is a convex set with a border and an interior, which in turn contain two types of cells. For illustrative purposes, let's say I ...
- 21
0
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1
answer
65
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Distribution for which one-sample t-test yields inflated type 1 error rates
Type 1 error rates of the one-sample t-test (two-tailed) can be inflated for example for data from the exponential distribution.
However, I am looking for distributions which yield inflated type 1 ...
- 1
1
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0
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30
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How to establish what distribution to compare my statistic to
Apologies for this poorly titled question, but I've been taking some statistics courses and sometimes when you try to learn too many things in too little time you want to take a step back to check if ...
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17
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Can we compare distributions in a subsampled Kolmogorov Smirnov test?
(stats newbie here)
The highlighted answer to Can you compare p-values of Kolmogorov Smirnov tests of normality of two variables to say which is more normal? refers to a paper* that says that when the ...
- 1
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0
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54
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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 ...
- 3
0
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0
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44
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Quantitative Methods for Evaluating Differences Between Two Distributions
I am working with a substantial dataset in which I need to compare the distributions of certain common features across different categories. The challenge I face is that due to the imprecision in ...
1
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1
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245
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Alternative to Binomial Test for Hypothesis Testing with Low Sample Size in Python
I am working with a dataset where I aim to test the hypothesis that a specific group behaves differently than expected across different conditions. I am assuming that if this group behaves differently,...
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1
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0
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107
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Testing the Hypothesis of Differences in Expected and Observed Frequencies in a Population [closed]
I have a set of data where I want to test the hypothesis that the player pool (a specific sample) overbluffs or underbluffs. I am assuming that if the player pool overbluffs or underbluffs, they do it ...
- 31
0
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0
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21
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Bivariate problem, what is the best model for this? Scoring probability depending on distance
I have been directed here from the main stackoverflow site, where i described my problem: here.
Basically i have a set of sports data containing shots with their distance to the goal and the result (...
0
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1
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253
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Distribution of rank differences for a paired dataset
I guess I have a rather simple question but I couldn't find the answer in previous posts. I have a paired dataset in which the same objects are ranked under two different conditions, here A and B:
<...
- 123
1
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2
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435
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Statistical test or distance metric for comparing different distributions?
I want to compare the distributions of two different groups to determine if they are statistically different. Here is an example:
...
0
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0
answers
44
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Comparing probability distributions from the same ML algorithm
Background: We are using a research tool that uses computer vision to quantify facial expressions (ie whether someone is smiling) from a webcam. The raw output for this tool is time series data ...
- 9
4
votes
1
answer
186
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equal *population* variances in paired t test
I I want to perform a paired t-test to check if there's some effect, I have the distribution of "before" and the distribution of "after" the manipulation. Do I need to assume the ...
- 41
2
votes
2
answers
122
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Distribution and variable analysis
I am doing a statistical test (program used is SPSS). On the basis of distribution and sample size, I have to chose the correct variable analysis. I also have to justify every decision. I have two ...
- 21
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0
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89
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Construction of a statistical test for a test statistic that fluctuates between 0 and 1
I'm working on a project where we currently take a look at some sort of efficiency measure, where we numerically integrate the area under the efficient frontier up to the current portfolios' ...
- 101
3
votes
1
answer
132
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Null Hypothesis in Paired t-test
Suppose that I was tasked to find if the mean difference between the current and starting salary of employees is greater than 15,000. How will my null and alternative hypotheses be?
Can it be:
Ho: ...
- 31
1
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1
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77
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Justifying data samples are from different distribution
Let $x \in \{0,1\}^N$, and
\begin{align}
D &= \begin{bmatrix}
x_{1} \\
x_{2} \\
\vdots \\
x_{M}
\end{bmatrix}
\end{align}
So that $D \in \...
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0
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78
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Statistical test for comparing number of clusters in data
I am performing $K$-means clustering on a dataset consisting of $n$ observations and $d$ variables, and I'm trying to determine the optimal number of clusters. Is there a test that can determine the ...
- 121
2
votes
1
answer
26
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In the T/Z/F/Chi sq test, are we looking at the Distribution of the Control dataset or Treatment dataset?
Pretty straight forward question.
Even if we are looking at the shape of the sample's distribution, are we sampling from the Control group or the Treatment group, or both?
- 1,021
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52
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No theoretical frequency should be less than 5 [duplicate]
Why does the theoretical frequency in chi-square distribution should not be less than 5? What's the concept behind pooling the preceding and succeeding frequency to make pooled frequency more than 5?
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2
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1
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647
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Can inferential statistics be used to study an entire population?
I have collected data from all the exercise science degree programs in my nation through databases (thus representing the population under study).
I would like to investigate whether certain credits ...
- 21
1
vote
1
answer
139
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What is the distribution and standard deviation of the number of Type I errors in hypothesis testing?
My question is from the book "An introduction to statistical learning" (2nd edition), chapter 13, exercise 2.
Suppose that we test m hypotheses, and control the Type I error for each ...
- 57
3
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1
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99
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How to reject a distribution given a sample?
Let's assume that we have the following vary basic problem:
We have a set of $N$ real numbers sampled from an unknown distribution.
We have a distribution that we consider as a hypothesis.
We would ...
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0
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180
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Smallest threshold for hypothesis test with asymptotic level alpha
Consider a distribution with parameter $\lambda$ that has density
$$f_\lambda(x)=\frac{x^4}{24\lambda^5}e^{\frac{-x}{\lambda}},x>0$$
Let $X_1,...,X_n$ be $n$ independent random variables drawn from ...
- 107
0
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0
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49
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How does the sampling distribution of a statistic relate to the t or z distribution?
My understanding of the output of statistical models is that you get a sample estimate. E.g. in regression you'd get a slope among other things.
This estimate is one of many possible slopes that come ...
- 1,031
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0
answers
47
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What is the appropriate test for my Facebook project
I have a little over 27,000 Facebook posts stored in a database. For each post, if the post has comments and replies, those are also stored in the database. The posts are from Facebook autism groups.
...
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0
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98
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Test if two dependent, unequal size samples are from the same distribution
I read Non-parametric test if two samples are drawn from the same distribution
and have tried permutation test, KS test
The issue is I have data of different sample size that are collected from the ...
- 1
0
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0
answers
538
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How do I test differences between two (non-normal) distributions?
I have a large dataset containing the peak velocities of different people. I have then split this dataset into two depending on an attribute (for example male vs. female). Each dataset now contains ...
0
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0
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281
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Hypothesis testing time series using permutation tests
I am performing a permutation (exact) test on some data and would like a sound check or to be schooled if what I’m doing is statistically valid or not. I have multiple time series that might ...
0
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1
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27
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Is there a test that can tell me, even for low counts, the probability that the obtained distribution of values eg from a die is truly random?
The background is that I have data and a number of independent variables. For each variable I want to ascertain the probability that the distribution of that variable's values is random for that data.
...
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1
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1
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33
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How to formulate the distribution and conduct a hypothesis test on the following situation?
The situation is that we toss a coin N times. We note the outcome of each flip and we find the distribution of how many times the coin flipped the 'same way' n times in a row, for n = 1,2,3 etc (for N ...
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1
vote
1
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36
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Time distribution: is it possible to determine whether calls are human-made or machine-made by patterns of the distribution
I'm relatively new to statistics, so the question is primarily about your advice on where I should start with this problem and read related material.
So, suppose I've got a temporal distribution of ...
- 111
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2
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129
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Can you use power analysis to find if the null hypothesis is true rather than not?
So in power analysis I have only ever seen it explained like in this statquest video:
https://www.youtube.com/watch?v=VX_M3tIyiYk
Where you have two distributions and you're trying to see if they are ...
0
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0
answers
25
views
Statistical Test for showing variance in peak values of two different populations?
I am publishing a paper and one of the reviewers requested that I provide a statistical method to show the difference between peak values (peak value = tallest bin in a histogram) of two populations. ...
0
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0
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88
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What does Kolmogov-Smirnov tells us when the p value is high?
I have a dataset which seems to be uniform by eye-examination.
I want to verify if this distribution is indeed uniform. I saw a couple of questions in here which suggested using a Kolmogorov-Smirnov ...
0
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1
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638
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Hypothesis testing for increase in sales
A company is planning to setup the option for self checkout (SCO) in all of its stores.
As a trial, they are looking to estimate the benefits of SCO in terms of increase in transaction volume by ...
- 53
0
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0
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93
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Likelihood a datapoint belongs to a given non-normal distribution
This problem is encountered by me lot of times.
Let's say I have a set of data points (x1, x2,....,xn) whose mean and standard deviation can be calculated. However these data points are non-normally ...
3
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0
answers
35
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Check if growth rate is worse than quadratic?
I was asked to move the question here (https://stackoverflow.com/questions/72692849/check-if-growth-rate-is-worse-than-quadratic)
Let's say I have collected a dataset for estimating algorithmic ...
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