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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22 views

P Value when t-statistic value is 4 D.p [on hold]

For example, when the t stat is -0.08451. I can find the value up to -0.08, but have no idea what do with the rest of the value as the answer comes up as incorrect.
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15 views

Statistical Test for Many different groups before and after an Event?

I have 200 species of animals and I want to check whether giving them a medicine can affect them in a significant way. I study 20 days before administering the medicine and 20 days after, such that an ...
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Probability of selecting maximum in bivariate correlated order statistics?

In a testing, ranking, or selection scenario, we have samples of size n where a measurement is correlated 0<r<1 with some second variable of interest; they are bivariate normally distributed. We'...
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What test to use?

We have a set of students in which every student does the following: A task on its own and then the same task on its own with an audience. A task in competition and then the same task in competition ...
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1answer
32 views

Is Friedman's test appropriate? [on hold]

Just want to confirm can we user Friedman's test if we have dependent variable as discrete variable? ...
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57 views

Bayes-Poincaré solution to the Behrens-Fisher problem 3: formal, self-contained statement + simulation results

This is a sequel to Bayes-Poincaré solution to k-sample tests for comparison and the Behrens-Fisher problem? and Bayes-Poincaré solution to the Behrens-Fisher problem 2: calculations for Jeffreys’ ...
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+50

Sample size determination using historical data and simulation

I am interested in the legitimacy and classification of the following approach to sample size determination. This question is inspired by “There is only one test!” by Allen Downey and “Statistics ...
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how to determine sample size for continuous metric

many online sample size calculator like http://www.evanmiller.org/ab-testing/sample-size.html only have sample size calculation for discrete metric(like conversion rate) how to calculate sample size ...
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1answer
48 views

Decide for three Bernoulli samples are some of them from the same distribution (or non of them) ? (do not use t-stat )

Please pay attention, I am interested in Bernoulli samples, and hope to find criteria specific to Bernoulli distribution, not using s Student's t-statistics or Mann-Whitney or etc., since their use ...
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1answer
123 views

Why is rejection of null hypothesis not a case of prosecutor's fallacy?

Here is what my understanding is: p-value - probability of finding the observed, or more extreme, results when the null hypothesis (H0) of a study question is true which is to say p-value$=P(...
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1answer
14 views

Mix of paired and independent data analysis [duplicate]

Is there any data analysis that can be performed on both paired and independent data? For example, we have scores on a questionnaire for individuals who were exposed and not exposed (control) to a ...
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6 views

How to interptet Jensen Alpha statistical significance?

When you regress portfolio excess returns against relative benchmark excess return you get a model in which the beta (slope) could be interpreted as the one you get from the CAPM, that is systemic ...
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1answer
36 views

p-value for two small Bernoulli trials

I am no statistician, but I am among the more statistically inclined at my workplace, so my coworkers consult me from time to time. I don't alway give the right answer, but I'd like to think I give ...
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1answer
56 views

chi squared goodness of fit test to check for normality

I have the following data: I would like to use the chi-squared goodness of fit test to test whether it comes from a normal distribution. How shall I go about it? In particular, I would like to know ...
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31 views

How to test for differences in gradient between time-series

I have time-series data where I've generated measurements of the same variable using different techniques, for a group of samples. An example of my data looks like this: ...
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1answer
17 views

Distribution of the partial likelihood ratio test in Cox model?

If I replace the partial likelihood of the Cox model https://en.wikipedia.org/wiki/Proportional_hazards_model#The_Cox_model instead of the likelihood in the likelihood ratio test https://en....
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1answer
22 views

Increasing the sample size for ttest without additional observations

I am currently handling some satistical data but my sample size is too small fot testing and my suppervisor suggested me the following idea: Consider 2 samples x, y and we want to compare the ...
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How to correctly state a multiple-comparison hypothesis pair

I need to compare multiple treatments over a predefined set of benchmark instances. However, I'm facing some difficulties on how to correctly state my hypothesis pair. I want to verify if there are ...
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1answer
20 views

Does higher F-statistics have higher p-value?

This post is a continuation of my previous post. After reading all comments and answer, I think that F-statistics tells us whether explanatory variables in a model is significant or not, as the null ...
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27 views

2 sample t test

I was thinking that a simple 2 sample t test is not that simple when dealing with skewed data. Considere 2 samples, each one with diferent skewness and kurtosis, both with a big sample sizes (say n > ...
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23 views

Hypothesis Testing Skewness in two-sample cases

Anyone knows how to do hypothesis testing on skewness for two samples? Better in R please. The null hypothesis is the skewness of two groups is the same. I've found the below two relevant posts, but ...
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Hypothesis test for Poisson process failure rates stays just as powerful for Compound Poisson

The book "Testing Statistical Hypotheses" by Lehman describes in section 4.5, a test for comparing the rates of two Poisson point-processes. This is the "uniformly most powerful" (UMP) test for this ...
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2answers
27 views

Which test is suitable

I have data from which I have to infer which day of a week is significant in terms of emotions. Please suggest me which statistical test I should use. ...
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41 views

Learn R or stats first? [closed]

I will soon start working a lot with statistical hypothesis testing and I plan to use R. my question, should I first focus on learning R or the stats? Thanks in advance :)
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For a Repeated measure-between Subject experiment should I visualize for each participant per condition separately?

So let's say I have 10 participants per condition (2 conditions). Is it necessary to visualize for each participant per condition or is it okay to visualize a long data format of 10 participants for ...
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2answers
43 views

Statistical test to check whether several datasets may be approximated with a single fit

I have a system that simulates some physical phenomenon. The true behavior is assumed to be described with a linear function $x(t) = a t + b$. Due to the randomized nature of the simulation each run ...
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Statistic analysis of results (t-testing, CHI Squared)

I am trying to analyse whether people are more conscious about using a list of tools to better protect their vehicles in different settings. So my null hypothesis is that people are not any more ...
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What are some statistical tests to perform from 8 samples (quantitative data) collected from 4 devices?

I need advice on the best statistical analysis to perform for data I collected from 4 devices. Device A and B are of the same height and are taller than device C and D which are of the same height as ...
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13 views

Statistical test for categorical dependent variable and continuous independent variable?

What's the appropriate statistical test for the relationship between a categorical dependent variable and a continuous independent variable? Say if there's an association between age and the type of ...
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1answer
58 views

Testing equality of marginal means of a multivariate normal random vector given estimated means and covariances

$x=(x_1,\dots,x_p)^\top$ is a random vector the elements of which are estimators that are known to have an asymptotic joint normal distribution $N(\mu,\Sigma)$. I have the estimated mean vector $\bar{...
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1answer
38 views

Which test should I perform?

I have 2 datasets. Dataset X looks like this: Jmp_o Nws_r 1 0 0 1 1 1 0 1 0 1 1 0 1 0 ... ... I calculate the ...
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1answer
17 views

Percent Difference From T-Test

I would like to obtain a percent difference between a physiologic measure from two groups (i.e., males and females). Say I obtain a significant difference from an unpaired t-test in blood pressure ...
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1answer
42 views

p-value and hypothesis testing [closed]

(The p value) Which one of the statements about the p value is correct? a) The p value is the predefined probability of making a mistake when the null hypothesis is false. b) The p value is the ...
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1answer
26 views

Alpha and Hypothesis Testing [closed]

(The type I error, alpha) Which one of the statements about the alpha level is correct? a) The alpha level is the predefined probability of making a mistake when the null hypothesis is false. b) The ...
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1answer
30 views

compare frequencies between 6 samples

I'm new to statistics so this might be a really newbie question.. I have a table in R as such: ...
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Multiple Comparisons Problem for non-independant subsets

I'm investigating whether a program was effective or not using BACI analysis and noticed that overall it had no effect (The 2-way ANOVA and non-parametric approach gave a p-value of about 0.5). I want ...
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2answers
32 views

How to do you find a power of a test of two means?

I am struggling with the following question Suppose we have randomly assigned 50 patients to the new treatment group and the other 50 patients to the conventional treatment group. Assuming both ...
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1answer
27 views

Which statistical test works for paired and grouped data?

I have a small set of samples of plants where I've made some changes to some but not others and want to know if there was any significant effect on the number of leaves as a result of this change. My ...
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6 views

Test of treatment effects based on aggregated data

I'm trying to find the treatment effect based on data that is aggregated at some level. To be more specific, the data look like this We observe at whether individuals exhibit a certain characteristic ...
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11 views

Bunching Estimation with Elasticity Heterogeneity

The bunching by Saez (2010) and Kleven and Waseem (2013) can be used to estimate the elasticity of taxable income. Kleven and Waseem (2013) argue that for heterogeneous elasticities excess bunching ...
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1answer
25 views

Multi test correction and hypothesis testing

I have 9 datasets with one predictor and one target attribute. For each of the dataset, I am testing for a single hypothesis - whether the attributes are associated. I have got the following based on ...
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1answer
22 views

Test for difference in coefficients: same sample, same outcome, but different explanatory variable

I do Ordinary Least Squares regressions and want to test if the difference between two estimated coefficients is statistically significant. I use the same sample, the same outcome, and only the ...
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1answer
32 views

DF Test Rejects Non-Stationarity in a seemingly Non-Statioinary Series

Let $Y_t = \rho Y_{t-1} + \epsilon_t$ and $Y_0$ be some constant. I generated a time series data for the above model like this ...
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2answers
104 views

How many trials are needed to get a statistically important proportion of 0.003 for a binomial variable?

I want to do an experiment and try to get an initial proportion (e.g., successful rate). The experiment will generate one of two results (either success or failure). I would like to know how many ...
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1answer
19 views

Nonparametric multiplecomparison tests for discrete data

Suppose I have $K$ populations each consisting of $n_i$ ($i=1\dots K$) observations $x_{j,i}$ ($j=1 \dots n_i$). Each observation is comming from a Bernoulli distributed random variable $X_{j,i} \sim ...
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How do I find the expected values and covariance matrix of the order statistics of iid random variables sampled from the standard normal distribution?

Recently I was trying to learn more about Normality tests and came to know about Shapiro-Wilk test for Normality. I understood most part of it but one thing I didn't understand is that how do I find ...
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10 views

Unplausible results in Hansens SPA-Test due to max(0, x)

In applying Hansens Superior Predictive Ability Test, I am receiving inplausible results for very bad alternatives, i.e. the p-value is 0 but should be in higher regions where you usually do not ...
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2answers
35 views

When can we use a z-test instead of a binomial test?

I read from https://www.spss-tutorials.com/binomial-test/ and noticed that "So when can we use a z-test instead of a binomial test? A rule of thumb is that P0*n and (1 - P0)*n must both be > 5, ...
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2answers
42 views

Understanding P-Value with respect to the Level of Significance [duplicate]

The definition of P-value is the probability of obtaining a sample that is more extreme than the ones observed in your data, assuming that the null hypothesis is true. That 's very well-explained in ...
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2answers
59 views

Should I determine whether a independent variable affects my data using regression parameter significance test or cross validation

Let's say that I'm trying to understand the factors affecting heart rate and I have a series of 500 measurement timepoints from 100 people. I have a wild mixture of categorical and continuous ...