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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Correct approach to define a null distribution by resampling?

I am trying to devise a test for significance by resampling from my data. The data consists of 60 individuals, grouped in 6 populations (10 per population). There are about 9,000 genes as ...
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58 views

“A property holds if it cannot be rejected”

Most examples in my Time Series Analysis slides and Multivariate Analysis textbook (Applied Multivariate Statistical Analysis, 6th Edition) conduct a hypothesis testing on data's normality, or zero ...
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20 views

Determining suitable seed number in R to randomly split data into training and test sets

Good day. I have sample size of 160 and I am randomly splitting them into 70% train and 30% test data sets. My question is about the set.seed() value which returns different random samples in each ...
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15 views

Statistical significance of co-efficient derived through several regressions for panel data

For the panel data that I have, I'm trying to run multiple one-variable regressions (y=ax+e) across time periods - i.e. one for each time period. Naturally, the a's that I find from each regression ...
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52 views

Statistical test for dependent data- comparing groups of pairs

I have a question about statistical tests for dependent data. This will sound a bit strange/extremely naive but pls bear with me- here is my problem formulation: I have 500 individuals, and I'm ...
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17 views

What is the difference between “paired” and “unpaired” versions in Wilcoxon's test?

Statistical tests can e.g. be used to decide whether to accept, reject or fail to reject the null hypothesis (the status quo). There are (apparently) two variants of this Wilcoxon's test: paired and ...
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9 views

conditional trees unexpected grouping — differences with chi squared test

I grouped some data with ctree (party package, conditional trees) (binary target) and the result is: ...
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23 views

Problems transforming from geometric distribution to normal distribution

I have this distribution that resembles a geometric distribution. I want to convert to a normal distribution so I can do some hypothesis testing using the properties of a normal distribution. I've ...
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1answer
93 views

Neyman-Pearson hypothesis testing with uniform random variables

This question is quite simple. We have a random sample $X_1, X_2, ..., X_n$ from $U(\theta, \theta + 1)$ and we want to test $H_0: \theta=0$ vs $H_0: \theta=\theta_1$ for some $0 < \theta_1 < 1$....
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P value of an empirical distribution from 500 Bootstraps

I have a time series, on which I calculated the outperformance of a trading system over the market, in order to get the mean hourly excess return of this strategy (the returns of the active strategy - ...
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12 views

Single summary statistic and p-value for a large number of correlated tests

I have several thousand measurements from an experiment, $\rho_i$, which are correlated. I can compute p-values $\Pr(\rho{>}\rho_i | \mathbf {H_0}_i)$ for each measurement by monte-carlo sampling ...
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1answer
40 views

Hypothesis testing - Which stat test to use with multiple choices (with both single and multiple responses)

I'm writing my master thesis but I have some problems with the analysis of the data collected using an online survey. The aim of the research is to assess if there are differences between two groups ...
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38 views

Which formula for t-test is correct?

When Population variance is unknown and n<30 we use t-test. x=sample mean, u=population mean, s=sample standard deviation, In my book and on many online websites i found t-test formula to be t=(...
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1answer
135 views

Paired or unpaired t-test and Wilcoxon signed rank test?

I am having a conceptual problem, of not being able to grasp whether my data is paired or unpaired. I have to test for the mean and median differences between two sets of data: SBP and GICS (see ...
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344 views

Which model for my data?

I have this data: ...
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Comparing distribution of two dependant binary variables different sample size

I have been searching for solution for my problem but keeps running into more questions so decided to finally ask for a bit of help. I am working with a dataset in which I want to compare efficiency ...
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1answer
41 views

Interpretation of the region of rejection in hypothesis testing in binomial distribution

The pharmacy company Life Co. has developed a new drug against insomnia. To check the effectiveness, this drug was tested with n = 10 patients. At present, the standard medication can cure 30% of the ...
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Quick test for significant difference in portions (and mean/average) between several group and likelihood?

I have a number of demographic and economic variables – both categorical and continuous – for a few different groups, one is a subset of the other. Estimates derive from IPUMS microdata from which I ...
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26 views

Plot power of a hypothesis test with $\alpha$

Let's take a simple one-sided hypothesis test (say the two sample t-test). The confidence level we want (probability of rejecting the null when it is true) is defined as $\alpha$ - usually set to 5%. ...
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36 views

Mann-Whitney-U for exponential distributions?

I have two distributions, that look like the following: They appear to be exponential and have different sample sizes (369 vs 60). I would like to do some hypothesis testing. I know that I can use ...
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1answer
34 views

How to find if people's preference is significant

I am trying to find out the wheither people prefer ads on Instagram or Facebook. As in are they more likely to choose x or y? Each person is given if you had to choose from and they pick x or y. ...
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32 views

Doing bootstrapping to test the distribution means

Whenever I have two samples (A and B), I've been doing conventional t-test to compare the significant difference in means if I find that these two sample come from normal population (using normality ...
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34 views

Hypothesis testing on a Bernouilli variable

I have a Bernouilli variable which is $1$ with probability $p$. I need to test the hypothesis $H_0:p<\theta$ vs. $H_1:p>\theta$, where $\theta$ is a given constant. The question is to find $n$ ...
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Best Test For Generalized/Nonparametric Behrens-Fisher Problem

First, because there seems to be a confusion of what the generalized Behrens-Fisher problem is a description adapted from [1]. We have $X_1,\ldots,X_m$ i.i.d. from distribution $P$ and $Y_1,\ldots,...
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1answer
26 views

How safe is that to ignore homogeneity of variances test and continue with Post hoc test?

I want to know if average time people spending on their favourite social media are statistically different. I consider here five groups, and the total number of participant is 700 persons. I have ...
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252 views

Distribution normality check

I can not solve the problem from my homework. We conducted two experiments. In the first, there were 400 patients, and in the second, 250. In these experiments, the effects of various drugs ...
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31 views

How to test seasonality of time series using One way ANOVA test?

I did perform a one way ANOVA test on my data, I'm having problems understand the results, my p-value is 0.0721 .
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Karlin Rubin Theorem UMP (Uniformly most powerful test ) Is it correct?

Suppose $X_1, X_2, X_3,\ldots, X_n$ are i.i.d. random variables with a common Poisson$(\lambda)$ distribution. $$X=(X_1, X_2, X_3,\ldots, X_n)$$ and $g(λ)=\lambda(1 - e^{-λ})$ , with $(λ>0)$ ...
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Two sample hypothesis testing with two groups

I have a dataset with two groups namely "treatment"(2556 records) and "control"(2525 records). The underlying data is about customer and group-wise number of customer care calls. The customer care ...
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12 views

Conditional Testing of Two-way Contingency Independence

I am reading about testing independence in two-way contingency tables from Mood Graybill and Boes's Introduction to the Theory of Statistics and is confused about testing independence. We have a two-...
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1answer
22 views

What model/significance test should I use to see if there's any significance between male and female sexual dimorphism on temperature over time?

In my lab I need to test if there's an significance between male and female sexual dimorphism on body temperature over 40 minutes. The temperature is simulated with a heat lamp and is turned on at 0 ...
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1answer
27 views

Inferential Testing

I am currently working on my dissertation, which is investigating the relationship between working memory capacity and problem-solving ability. I have two independent controls task 1 and task 2, both ...
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hypothesis testing doubt

I have the OLS regression model: $Y = \beta_0 + \beta_1X_1 + \beta_2X_2 + \beta_3X_3 + \beta_4X_4 + \epsilon$ I want to check the hypothesis: Ho : $\beta_2*\beta_3$ = 1 Will I use the Delta ...
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1answer
35 views

Can point-system be used for hypothesis testing?

I've created a point system for the bestseller's list (I've 52 weeks' lists).The list has 4 categories of genre (romance, thriller, fantasy, literary fiction). ...
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predict important markov chains(paths to an event) with confidence

I need help in validating my current approach as well as find any alternative approaches I could use in order to tackle issues like below. I have a dataset like below and I need to find important ...
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1answer
116 views

Hypothesis testing control vs treatment when the outcome tends to vary over time

I want to test the effect of a treatment on a continuous outcome (specifically interested in increase in average in the treatment group). The experiment is run over a period of time. But the problem ...
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24 views

Compare sales data over time in sequence

I am very new to stats, please advise how should I approach to solve the below problem. I have data like : My objective is to see how customers are spending from one Quarter to the next Quarter. I ...
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1answer
14 views

Data in the Mann-Whitney test

I have a simple question. I wanted to compare two independent survival curves, for example Online resources tell me that the Mann-Whitney test can be used to test two independent groups or ordinal ...
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Why $\alpha$-level confidence interval consists of hypotheses under which p-value is larger than $1 - \alpha$?

I have read in an old paper that "Typically, an $\alpha$-level confidence interval consists of those hypotheses under which the $p$-value for the experimental outcome is larger than $1 - \alpha$". If ...
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39 views

Designing hypothesis test around failure rates

I'm trying to devise a hypothesis test for failure rate data of machines. The gist is that there are some machines in a factory that run all the time. They fail from time to time and are promptly ...
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1answer
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Testing whether two timeseries samples are from the same population

I would like to test if different timeseries samples (over the same period of time) are plausibly from the same population. e.g. popularity of movie Avengers over time from different websites. The ...
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7 views

Testing Response Model

I'm thinking about strategies to examine how well a churn model performs. And, I know one question I'll receive is can we just target customers in the top decile of the churn model to evaluate model ...
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How to test for sample selection bias in heckit estimation?

I'm doing a heckit two step estimation by hand where i first estimate the labor force participation, compute the inverse mills ratio by using the linear predictors of the model and add it as an ...
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Is there a way to run test for A vs B for metric cost per lead = marketing cost / lead?

Is there a way to run test for A vs B for metric cost per lead = marketing cost / lead? the denominator is the total number of leads submitted from the marketing audience. the numerator is the ...
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1answer
23 views

What Null hypothesis does vegan::anova.cca(by = “terms”) test against?

I ran a distance-based Redundancy Analysis with the vegan R-package. Statistical significance of axes and explanatory variables can be tested with the anova.cca() function. Form Legendre et al. ...
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28 views

Correct statistical test to compare two results from different algorithms ran on same data set

So I have an algorithm $A$ and an algorithm $B$ that is run on a set of $n$ documents. The documents are financial forms that consist of data that algorithm $A$/$B$ extracts. For each of the $n$ ...
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What statistics should be used in this scenario? mixed-model ANOVA?

For my research I am comparing the target strength (acoustic reflectance) of three different wing locations of a moth. Measures of target strength are taken across a range of frequencies between 20-...
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960 views

Why are the cut-offs used for Bayes factors and p-values so different?

I am trying to understand Bayes Factor (BF). I believe they are like likelihood ratio of 2 hypotheses. So if BF is 5, it means H1 is 5 times more likely than H0. And value of 3-10 indicates moderate ...
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Hypothesis testing with porportions

I'm currently working on an experiment where in each individual test multiple subjects (between 16 and 22) are presented with two options. I have recorded the proportions of how many subjects in each ...
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F-test equivalent for residuals from robust regression

I'd like to compare fits for two datasets that have clearly non-normal errors. Is there a way to compare nested models fit with robust regression?