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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Constant value in Neyman Pearson lemma

To know the k value in Neyman Pearson lemma, do we need to know the alternate hypothesis. To what I understood (from articles like PenStateNotes), we could get value of k using null hypothesis and the ...
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1answer
243 views

Relationship between Matthews correlation coefficient (MCC) and the Pearson's Chi-square

I would like to find a reference showing that the MCC follows a Chi-square distribution. This is suggested in this Wikipedia article: https://en.wikipedia.org/wiki/Matthews_correlation_coefficient, as ...
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Statistical test for significance on difference in scoring values on ordinal scale between two groups

Statistical test for significance of the difference in scoring values on an ordinal scale between two groups. Respondents were asked how worried they are about something on a scale between 1 (least ...
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Is my lottery machine fair?

I have a lottery machine with 100 balls inside. Each trial, I draw 7 of the balls and record their numbers. How do I determine if the results are biased or not?
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10 views

How to compare two samples with not independent observations within each one?

To best of my understanding, both parametric two-sample t-test and non-parametric Mann–Whitney U test assume that observations are independent. I believe that making a permutation test (randomly ...
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167 views

Questions about non-standard test statistic for difference of two population proportions

Background I'm considering the number of observed 'successes' $x_1$ and $x_2$ from $n_1$ and $n_2$ independent trials respectively. These counts can be considered realisations of random variables $...
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10 views

One-sample t test for the non-significant Shapiro-Wilk variables, else Wilcoxon

One of the reviewers for my paper did not understand why I compared the analyses to zero. Can you please help me understand if what I do does not make sense or if it does and I just need to convey the ...
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10 views

Multiple hypothesis testing for Chi-square

I am writing an article in which I am testing simultaneously multiple hypotheses involving two concepts: 1) Quality and 2) Gender But as the quality is a more complex concept I present it as ...
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10 views

Testing differences in 5 star rating (Which hotel to choose)

Say, I want to choose a Hotel with the following ratings (1-5) on TripAdvisor. This seemed interesting if the mean for the Hotel with smaller number of votes is bigger than the mean of the hotel with ...
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13 views

How do you quantify the success of a billboard?

For example if an internet company puts up a billboard for 3 weeks in a city with the words "Try our product". How do we statistically quantify this ad worked? Let's use website traffic as our metric. ...
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238 views

compare multiple algorithms in the same dataset

I want to do a comparison between multiple algorithms when they applied to the same dataset. For example, I have a set of texts in Arabic and another version translated to English. I did a sentiment ...
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14 views

How to get P value from U and Eps

In a discussion on Mann-Whitney test, it is explained how to calculate U and Eps, where U is Mann-Whitney’s statistic and Eps is associated with the normal variable. The discussion is in the pdf ...
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What kind of statistical test is appropriate for the following example?

I ran an experiment varying the temperature and the quantity of chemicals added for the removal of 4 contaminants (A, B, C and D). The data obtained from this experiment was (in R): ...
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two sample analysis with outliers

I've got some data from two groups which have different sample size. (univariate variable like 'price', and want to test whether they have significance difference ) The sample size of 'A' is 10,000 ...
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22 views

Statistical significance in mutations in two groups

I'm doing an analysis examining the mutations of a set of ~3 genes in 4 different populations. For Gene 1: In Group A 33/540 have that mutation, Group B 66/100, Group C 15/213, and Group D 20/32. And ...
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14 views

Simple question on t-test

I am currently writing an assignment in which I would like to add a short event study on the impact of several events on the stock price of a company. I used a market model with an estimation period ...
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24 views

Peacock Test Implementation in R

I have two empirical distribution (without access to the observations themselves). So, in order to see if the empirical distributions are "significantly" different, I took two large random samples ...
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66 views

How likely is sample A and sample B is from distribution C? [on hold]

Let's say I have a sample A: [0,0,0,1] and another sample B: [2,0,5,10,100,3,2,6] I would like to know the probability that A and B are both picked from the same population C. I tried applying a ...
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Is this an example of a T-statistic?

Excerpt from a study https://www.researchgate.net/publication/328838624_No_More_FOMO_Limiting_Social_Media_Decreases_Loneliness_and_Depression: Although not every subject complied perfectly with ...
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240 views

Should I use the Log-Likelihood (G2) test to compare word frequency across corpora?

Apologies for cross posting this I posted in Linguistics but so far there have been no takers. I need to compare the frequency of occurrence of a word in two corpora. Take for example the word fail ...
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1answer
26 views

Test for equal mean

I have a control experiment and an experiment. In these two experiments, I can detect different peptides. The presence of the peptides in the experiment is measured by determining the concentration of ...
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178 views

Insignificant ANOVA, but significant linear and quadratic effects

I performed with SAS an ANOVA and I got insignificant differences for each coefficient. So I planed to looked at the linear and quadratic effects of the Ca concentration (6 levels), and the linear was ...
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3answers
23 views

Hypothesis testing based on the concentrations of two cigarettes' samples

A cigarette producer sent two samples, one for each laboratory, which he thinks to be identical. The laboratories determined the concentration (in mg) of nicotine in each sample and they obtained the ...
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1answer
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Relationship between Mann-Kendall and Kendall Tau-b

Do the Mann-Kendall and Kendall Tau-b use very similar test statistics? It seems that everytime I perform both tests, they always provide the same p-value and same conclusion.
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How to check if means and variances are normally distributed?

From here I read that The t-test assumes that the means of the different samples are normally distributed; it does not assume that the population is normally distributed. By the central limit ...
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1answer
169 views

Is a likelihood ratio test appropriate when checking for unnecessary lags in a VAR?

If I trying to estimate the proper VAR to do a one period ahead forecast, but I am unsure of how many periods I should lag one of my variables, for example if I should lag it 2 periods instead of 3, ...
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273 views

Johansen cointegration testing: rejecting at 10% vs. 1% level

I am testing for cointegration using the function ca.jo from the packeg 'urca' in R. I am struggling to understand the output. According to my knowledge, the $H_0\...
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26 views

Advantage of the Gail-Simon Test (qualitative/ crossover interaction test)

It is common to use products of original variables as the basis of testing whether interaction is present. In regression analysis, for example, we can include both main effects and the interaction and ...
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14 views

Comparing survival times in overlapping groups

I have a following statistical setup I don't know how to attack: I have two therapies: say A and B. For some patients A works better, for other B works better. I want to direct patients to their ...
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1answer
41 views

Comparing heteroscedastic groups with sample sizes from 1 to 24… No valid tests?

I'm comparing 1 continuous variable across 36 groups (nurses grouped into 36 hospital units). Several groups have only 1 observation, but most have more, ranging from 1-24 observations per group. ...
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2answers
24 views

Statistical significance of binomial variable when sample sizes are different?

Suppose we have two groups of students given the same difficult test. However, one group of students was given an extra training session before the test. normal students = 123 students with extra ...
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4answers
83 views

What test do I use to check if two samples came from different population?

I'm aware that t-test checks if two sample data sets have the same difference in means with confidence. But testing difference in means is not equivalent to testing if the two distributions came from ...
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42 views

Is learning how to do deep learning and machine learning actually harder than learning how to do regression (lm, nlme), t-tests, classical statistics? [closed]

It seems like because most people are still using regression like logits or covariance pattern models and the work of Ronald Fisher to solve problems and machine learning is less popularly used, is ...
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Hypothesis test for pixel matrix equivalence

I'm going through this tutorial and I'm reworking it in R and I was able to do so. I tried to extend this tutorial by thinking of ways to objectively detect differences in images; e.g., can I run a ...
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Asymptotic relationship between tests of compact composite nulls and one sided tests

A motivating example Let $x_t\sim N(\mu,1)$ for $t=1,\dots,T$. Consider testing the null $H_0: \mu\in[-1,1]$ against the alternative $H_1:\mu\in\mathbb{R}\setminus [-1,1]$. The natural (UMPU?) test ...
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21 views

What is the correct statistical test?

I'm despaired about planning the evaluation of my experiment for my bachelor thesis and urgently need help with the selection of statistical tests. Brief outline: I want to transfer the mood ...
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29 views

Statistical test to measure whether certain candidates progress further in a job application process

If I have an interview process where people are phone screened, then if they pass then are moved unto another stage, and then another stage etc until they get an offer. I want to identify the ...
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Reporting difference in distributions for text

I am working on a problem that can be translated to determining which of two corpora generated a given sample text. I have a hypothesis for before some processing and other for after processing, and ...
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Is chi squared test of independence correct with control group?

I'm analyzing some data from an experiment in which passage of time between conflicting tasks is my independent variable and one of my dependent variables is a dichotomous one ("A","B"). I also have a ...
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Implementation of Hypothesis test on R² for regressions in cross-sectional setup

I am confused by the paper of Kan et al. (2013 - "Pricing Model Performance and the Two-Pass Cross-Sectional Regression Methodology") which proposes the execution of hypothesis tests on R² of ...
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Hypothesis Testing : To Test the presence of Seasonality Given the Seasonal Indices

I was just looking at this tool by Professor Hossein Arsham to check for the presence of seasonality in the data using seasonal indices. https://home.ubalt.edu/ntsbarsh/Business-stat/otherapplets/...
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Using the $Z$-test instead of the binomial test for small $n$ - effect on power and Type I error

Setup Let $M \sim \text{Bin}(p,n)$. Let us then state the following two hypotheses: $$\begin{align} H_0: p = 0.5 \text{ vs } H_1: p > 0.5 \end{align}$$ To test these hypotheses, I could use the ...
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Is this a sign of a bad IRT implementation? [on hold]

This data is from the Indonesian UTBK SBMPTN (a university entrance exam). It is said to use Item Response Theory for scoring. I found something interesting about it. The image below shows the ...
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2answers
306 views

Test to identify outliers with R

I would like to identify outliers in a sample of 6,000 observations. My variable doesn't follow a normal distribution and my series is spread out on the right. So an extreme value is not necessary an ...
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1answer
35 views

Apply normal or not-normal test to heterogeneously normal data sub-sets

I have a dataset made by measuring something on standard dilutions ranging from let's say 10, 100, 1000 and 10000. I checked how the results are distributed with the Shapiro-Wilk test, and it turns ...
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0answers
11 views

games-howell test with multiple independent variables

my data doesn't meet the homogeneity of variances criterium. After a welch one way test I wanted to perform a post hoc games-howell test since it doesn't require the homogeneity of variances criterium....
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2answers
38 views

Clarification on equal variance vs unequal variance t-test

In unequal variance t-test (Welch t-test): $$H_0 = \text{No difference in means, but variance can differ}$$ $$H_1 = \text{Two sample means are significantly different}$$ I don't see the point of ...
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Why is the population standard deviation approximated as the sample standard deviation?

This question addresses calculating a p value from the mean and standard deviation statistics of a sample. I understand that the -general- philosophy is to divide the sample standard deviation by the ...
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1answer
20 views

Test for equality of means for vector-valued random process with different variances

I am studying linearity range of an RF amplifier (henceforth DUT). For that I am stimulating the DUT with a periodic deterministic probe signal (which is known only roughly) and measuring the DUT's ...
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36 views

Using Chi-Square-Test for single item likert type hypothesis testing?

I conducted a Survey to find reasons why firms invest in a specific asset. I asked them in a Likert-question if different aspects are a reason to invest in [asset]. The Response for each aspect can be:...