# 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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### Minimum sample size for AB testing on a proportion derived from an extremely rare event

I am running an online experiment on a proportion that is the rate of an extremely rare event. 95.5% of the observations have 0 for this event. The majority of the rest have 1 for that event. Hence ...
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### Is a split-plot ANCOVA the right test?

I am writing my master's thesis and I just can't find no peace of mind.. I hope you can help me with understanding whether the chosen statistical test works or let me know if there's a better ...
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### Are two likelihoods statistically different?

Here is an example that will help me ask my question. Let's say, I have the red and blue distributions as below, both of which are normal distributions (n = number of observations): Then I introduce ...
1 vote
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### How is t-test on non-normal distribution justified?

I have heard that when the sample size n is large enough, we can apply the t-test to non-normal distribution due to the CLT. But as far as I can see, the CLT only justify the normality of the sample ...
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### Which statistical Test should I use/ Comparing 2 groups

I am new to statistics, can someone guide me regarding the test I should use to compare the foot dimensions of 9 subjects to footwear dimensions (we have 2 footwear brands). So, to simplify, I have ...
1 vote
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### Can we apply hypothesis testing to not-actively sampled groups?

For argument's sake, in the below please assume that the hypothesis test we'd be considering would be a simple z-test to check whether an observed difference between two groups' means or proportions ...
1 vote
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### How to account for overlap in individual studies in meta-analysis of meta-analyses (umbrella analysis)

I want to conduct a meta-analysis of meta-analyses (aka umbrella analysis). A potential issue is that within each individual meta-analysis I want to include there is some overlap between the studies. ...
1 vote
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### Compare subgroups on before and after intervention

Assume the following research experience. A group of researchers went to a school. On the first day, they gave a questionnaire about a topic for the students to fill. The next day, the researchers ...
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### How to perform significance test for a time dependent multiple linear regression equation?

Let me describe the problem: The general form of multi-variate regression model is given by $$Y = b_0 + b_1x_1 + b_2x_2 + b_3x_3 +....+ eta$$ And the statistic to test the significance of coefficient ...
1 vote
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### Are T-tests good choices here?

I would like to test if two groups of participants (dark-eyed and light-eyed individuals) respond to a drug differently over time. The hypothesis is that the drug reaches its peak effects sooner but ...
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### Statistical Signifance Test for discrete data

I'm fairly new to statistics and want to perform a statistical analysis (calculation of p value) for data I collected, but I'm unsure if I'm doing it correctly and would like some feedback/help. I ...
1 vote
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### What metric does the 95% confidence interval of a 2-sample t-test cover?

I'm trying to better understand what the 95% confidence interval is supposed to cover (in the context of a two-sample t-test). I had always been under the impression that the 95% confidence interval ...
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### How to apply probability / bayes theory to classification issue?

I have a system of Codes which is updated every year, so some codes are deleted and some new codes are added. So here we have 4 versions of this system. Now, I received a list which contains some of ...
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### How to apply probability / bayes theory? [duplicate]

I have a system of Codes which is updated every year, so some codes are deleted and some new codes are added. So here we have 4 versions of this system. Now, I received a list which contains some of ...
26 views

### What statistical test to choose weekday vs weekend occurrence

I have categorical data which shows the number of occurrences per day of the week, with 0 being Monday and 6 = Sunday ...
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### How to compare two groups of discrete states?

The dataset includes 25 patients in one group (low intensity of a certain parameter) and 27 people in another group (high intensity of the same parameter). One or more teeth were treated for each ...
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### Hypothesis testing with two means: How to do it properly?

I have a dataset which looks like the following: Value A Value B 1.2 100 1.3 200 1.4 300 1.1 433 1.3 320 1.2 210 1.5 108 I want to test the following hypothesis: *If I take an n-dimensional ...
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### How can I improve the results of such a binomial test? Was it a good choice for this problem?

I have a dataset that looks like this: initial final division fsa hrs_prev fsa/hrs_prev 2020-01 2020-06 A 0 168 0 2020-01 2020-06 B 14,29 177,45 2020-02 2020-07 A 9,52 177,45 0,054 and so on <...
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### If in the Fisher's exact test, one did not condition on the margin totals, how would the margin totals be factored in the calulation?

It states in the following post What does the assumption of the Fisher test that "The row and column totals should be fixed" mean? that: Fisher's exact test conditions on the margin totals, ...
1 vote
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### Hypothesis testing: Calculate beta without PDF of H1

I've found pages that show how to mechanically calculate beta as 1 minus alpha and/or show beta in the context of a PDF for the alternative hypothesis (H1 or Ha). If you don't have a conjectured mean ...
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### Help with interpreting a q-q plot [duplicate]

This is the q-q plot I got when testing residuals for Normality in a simple regression. Would you say that residuals are normally distributed or not? Should the data be transformed? I would say that ...
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### Hypothesis testing of two dependent samples when pair information is not given

For two samples equal sample size $(n\ =\ 100)$ that are randomly selected and dependent, only the sample means$(\overline x_1, \overline x_2)$ and sample standard deviations($s_1,s_2$) for both ...
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### The concept of a specification test

There is a confusing facet of the concept of a specification test. According to many textbooks, a specification test is roughly a statistical test investigating whether assumptions in a statistical ...
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### Portmanteau statistic explanation

I am trying to test the autocorrelation of a VAR model using the Portmanteau statistic. I am using the R function serial.test(). I would like to fully understand ...
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### Is log-rank parametric or non-parametric test, and why?

How is the log-rank test a "non-parametric test" according to wikipedia.org if one has to specify the parametric survival model for this test? We may run log-rank under the assumption of ...
1 vote
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### On a survey, when checking for effect some answers have on other answers, do we always need to check for effect of random question sets?

Say someone runs a survey with, 100 binary question to which 10,000 randomly selected people responded. For 5 of those each questions (#20 to #24), answers looked like this (lets call this set of ...
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I have a table that looks like this: initial final fsa_top hours_top fsa_bot hours_bot 2020-01 2020-06 1540.33 35222.21 984.5 28765.22 2020-02 2020-07 1765.43 36782.99 976.22 27666.07 and so on I ...
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### How should one re-formulate hypothesis after hypothesis testing or whether or not to discard data after significance testing or archive it?

@Nalzook summarized what he thinks Ronald Fisher did. Ask a question. Propose a null hypothesis based on the question. Do some experiments, and collect some data. Assuming the null is true, calculate ...
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### How to assess effect of a treatment on different groups, if groups have an effect on the measured variable and each group only receives one treatment?

Let's say I want to assess the effect of a treatment (A or B) on a continuous variable measured on subjects. The subjects I want to experiment on are organized into "groups". It has been ...
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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 ...
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### Binomial test for absenteeism

I have a dataset that looks like this: Company hrs_prev fsa fsa/hrs_prev A 140 5 0,035 B 145 2 0,01379 C 140 60 0,4286 A 155 20 0,0129 A 180 25 0,1389 B 120 0 0 B 130 0 0 etc etc etc etc ...
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