Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [hypothesis-testing]

Hypothesis testing assesses whether data are inconsistent with a given hypothesis rather than being an effect of random fluctuations.

1
vote
0answers
15 views

test for moderation in a quadratic regression model

I am trying to test for moderation in a quadratic regression model. my results show significant evidence of a quadratic relationship on one of the independent variables (x1) and also significant ...
0
votes
0answers
13 views

Can an A/B test be structured as “show new content” vs. “don't show anything”?

Apologies if this question has been asked before, but after Googling, I struggled to find anything that really answered my question. Say I work for the marketing dept. of a company, and we have an ...
2
votes
0answers
38 views

Understanding that a hypothesis test does not depend on a certain parameter

I have a very big doubt regarding a test not depending on $\theta_1$. Suppose I have: $$(X_i)_{i=1}^{n}, X_i \stackrel{iid}{\sim} N(\theta, 1), \hbox{ that is } X_i \sim g(x_i, \theta) = (2\pi)^{-1/2}...
1
vote
0answers
18 views

Likelihood ratio test and sample statistics

Given a sample $\mathbf X =(X_1,...,X_n)$ from a parent random variable $X$, Neyman-Pearson's test for two point hypotheses $H_0$ and $H_1$ is the one defined by the critical region $$C=\left\{\mathbf ...
0
votes
1answer
30 views

Statistics Homework Help [closed]

Not sure how to tackle this question, can someone help me? A team of medical researchers carried out a study among swimmers to investigate a possible link between exposure to chlorinated swimming ...
0
votes
0answers
11 views

Bayesian hypothesis testing and NHST - Which is better

i've seen a lot of approach for hypothesis testing and i wonder if some test (mainly those coming from frequentist inference) like the null hypothesis testing are still relevants today. I've seen some ...
1
vote
1answer
28 views

Significance Test with dichotomous variable

I have a set of data. The data contains 30.000 observations of a set of several variables. One of those variables indicates a nominal segment classification. In total there are six different segments. ...
0
votes
0answers
12 views

Computing a DV for a 2x2 study design

I'm conducting research for the first time (for my master thesis) and have some trouble. I have sent out a questionnaire to research mortality salience effects on purchase intention and price ...
1
vote
1answer
24 views

Sample size needed to prove equal proportions

We are trying to prove that three groups have the same proportion of some effect. We are struggling with formulating the null hypothesis, and whether or not the sample size is big enough. The ...
0
votes
1answer
27 views

Which statistical test to use on half-normal distribution of discrete data points

I have two datasets. Each contains integer data points, ranging from 0 to 34 and they follow an approximately half-normal distribution, as 0 occurs very frequently and 34 occurs only once. I would ...
0
votes
1answer
28 views

How to use ttest and reject null hypothesis

I'm using ttest for two populations, I know that we can reject the null hypothesis when the p-value is less that 0.1 (with 90% confidence). but does it make sense to get a pvalue of say .17 and then ...
0
votes
0answers
7 views

Manually zero bounding a metric before significance testing in an experiment

I’m trying to replicate the methodology described in this paper to improve the sensitivity of a significance test on a metric (number of purchases) in my experiment on an ecommerce website. In short, ...
1
vote
0answers
8 views

Best way to test the difference in means for Tweedie distributions?

What is the best way to test the difference in means for two samples of data that follow a Tweedie distribution? (zero inflated, tweedie power parameter ~1.7) The data represents the number of ...
0
votes
0answers
12 views

Comparing frequency of incidence pre and post intervention for one individual

I have data for one individual about the frequency of challenging behaviour pre and post intervention. I have the dates of incidence (and can therefore calculate daily average number of incidents or ...
0
votes
1answer
53 views

A question about hypothesis testing [closed]

Question I am actually finding no clue how to start with this sum. Please help. Thank you.
1
vote
0answers
38 views

What is the closed form or analytical expression of the distribution of p-values, if we *don't* test point Null hypotheses?

Problem If we test a true point Null hypothesis using a continuously distributed test statistic, it is possible to prove that the $p$-value resulting from such test is a realisation of a uniform ...
0
votes
0answers
15 views

Which test should I use to compare three geometric means?

I'm trying to use some test to compare three geometric means of some dataset, to see if there are significant differences. I want to compare A with B, B with C and A with C, but I'm unsure of which ...
1
vote
0answers
37 views

UMP test for $H_0:p=0.5$ vs $H_1:p\neq0.5$?

Let $X_1,\dots, X_n$ Bernoulli trials. I know that the UMP tests for $$H_0:p=0.5 \quad\text{vs}\quad H_1:p>0.5$$ and $$H_0:p=0.5 \quad\text{vs}\quad H_1:p<0.5$$ can be obtained with the Neyman ...
1
vote
0answers
20 views

Is there a quick way to check the significance for each category of a predictor?

I ran a chi-square test of independence on this data set. ...
2
votes
1answer
21 views

AB Testing vs Hypothesis Testing

I'm having trouble making the full connection between AB Testing and Hypothesis testing. Hypothesis Testing Conducting a test to compare two means, we need the standard deviation of both samples, and ...
0
votes
0answers
17 views

Setting an A/B test for electronic devices after an update

I want to set up an experimental testing or A/B test. We have electronic devices on the field. Recently we had a problem with the keydoor. It started falling(it wont open(Fail) after we try to open ...
3
votes
1answer
41 views

Proportion Test: Z-test vs bootstrap / simulation - different results

I'm learning hypothesis testing, and going through the following example: The CEO of a large electric utility claims that 80 percent of his 1,000,000 customers are very satisfied with the service ...
1
vote
2answers
46 views

Normality vs normality of residuals

I am currently trying to perform a hypothesis test on the difference between four means. Initially I was trying to use ANOVA but then realised I may not meet the assumptions for this test and may need ...
0
votes
1answer
15 views

Is a difference of means test compromised when the treatment is at a higher level than the unit of measurement?

To paint a scenario, let's say that I'm interested in the impact of a new tool on the speed with which work is performed. I give 100 employees access to this new tool while another 100 use the current ...
1
vote
2answers
66 views

What's the right test of significance for a categorical independent variable and categorical dependent variable?

I have data that looks like this. It goes on for about 10,000 rows. Goal is always TRUE/FALSE and category has five options. ...
0
votes
1answer
26 views

What's the right t-test for comparing the distribution of a response variable across two categories for the same sample?

I have data where every record has an ID, a numeric value (that represents the number of times each ID took a particular action) and a binary state that represents whether they achieved a goal. ...
0
votes
1answer
16 views

T-test: Difference in Mean: which increased faster in a given time period?

Is it possible to do hypothesis testing on which mean increased faster? For example, samples are A (1994) - 1, 2, 3 A (2014) - 2, 4, 6 B (1994) - 1, 2, 4 B (2014( - 2, 4, 16 Obviously the mean of A ...
0
votes
1answer
37 views

Twenty samples should be the same. But How should I test that

I have a table derived from a group of polypeptides or proteins. Because they are proteins they are made up of 20 amino acids. Iff a group of proteins contains a random sample of amino acids then the ...
0
votes
0answers
10 views

Why is the AUC when plotted against the wilcoxon rank sum p-value, result in a plot that is not linear?

I have a binary response variable with many continuous predictor variables (about 5000). I first computed the AUC for each predictor variable, then computed the p-value associated with the AUC using ...
1
vote
0answers
11 views

Largest connected group of identically distributed nodes in d.r.v sample graph

I have come across an unfamiliar and somewhat interesting problem while attempting to write an algorithm for an image processing application and was wondering if any of you had any ideas that might be ...
1
vote
0answers
15 views

Calculating target mean to validate if I should drop column with missing values is correct?

I am working on the KDD 2009 Cup Data Set (The Small one) and I have a question about preprocessing data. It has a lot of columns with null values, some of them have more than 90% of missing. Reading ...
0
votes
0answers
25 views

How to report the results of the Tukey HSD syntactically/formally correct?

For the ANOVA i use this form: F(2, 1279) = 6.15, p = .002, w^2 = .010. Let's say i did some post hoc testing and the result is this: ...
0
votes
1answer
28 views

Difference Between Notation of Two Sample Hypothesis Tests

Does this hypothesis test: H0: μd = 0 H1: μd ≠ 0 Represent the same as this test: H0: μ1 = μ2 H1: μ1 ≠ μ2 Since the first is asking if there is a difference between the true mean of the two ...
0
votes
1answer
29 views

Which statistical test should I use - likert scales and multiple categorical groups?

I would like to run a test to see if the difference in scores on a 5-point likert scale (Strongly Disagree to Strongly Agree) is statistically significant between 6 different and distinct groups. I ...
0
votes
0answers
17 views

Hypothesis testing on set of comparisons experiment

Imagine I'm running an experiment where I'm comparing my method with $M-1$ competitors and I'm collecting the results for $T$ different runs. I would like to test the hypothesis of "my method is the ...
0
votes
0answers
26 views

Hypotheses Testing and Calculating Statistical Significance on Time Series Data

I'm trying to compare the growth (annual change) in average house price in the UK before and after the EU referendum. I want to test whether the decline in growth (since the referendum) is ...
0
votes
0answers
11 views

Grouping hypotheses, and applying FDR to each group separately?

Suppose I have two sets of hypotheses, $A$ and $B$, and I want to control FDR. When is it valid to control the FDR of $A$ and $B$ separately, vs controlling the FDR of $A \cup B$ jointly? One ...
3
votes
2answers
52 views
1
vote
1answer
47 views

t-Test with small sample sizes (10)

I am looking to compare the means of two sample populations of size 10. Ideally I would like to use an independent t-Test however I am concerned that the sample size is too small, as I don't know for ...
0
votes
0answers
25 views

Response time of sequential probability ratio test for continuous-time observation process?

I hope to simulate the response time of a binary decision problem given continuous-time observation using sequential probability ratio test (SPRT). Traditionally with discrete-time SPRT, we calculate ...
0
votes
0answers
17 views

Testing data samples(vectors) if they came from the same distributions

I've found whole bunch of tests here for non-parametric statistics: Nonparametric_statistics But since I'm not good at statistics: do those tests work only for random variables? I have two sources of ...
0
votes
1answer
27 views
0
votes
0answers
29 views

How to perform Granger-causality?

I have a question regarding Granger-causality. I want to test if 1) [y2 and y3] do not Granger-cause y1 and test if 2) [y2] does Granger-cause y1. The equation is as follows: y1-3, t = ...
0
votes
0answers
19 views

Difference in means test for coefficients from two matching models

I have a model estimating the effect of a treatment on two different populations, and a theoretical hypothesis that the effect should be larger for population A than for population B. I can address ...
1
vote
0answers
16 views

Goodness Of Fit Testing When Multiple Parameters Are Estimated

I am working with independent data points $X_1,...,X_N$ each of which, under my model assumptions, is a sum of exponential waiting times with different rates, and so should come from gamma ...
0
votes
0answers
10 views

Location level a/b testing sample size

We are setting up experiments to measure impact on the city level. Customer in certain cities are treated and we have list of holdout cities with similar behavior. Measurement of lift of the ...
1
vote
0answers
13 views

Bootstrap test of means using pooled groups - is there a problem?

In his book "Resampling: the New Statistics" (available for free online), Julian Simon presents several examples where he Bootstraps the differences in group means, assuming that the observations of ...
0
votes
1answer
33 views

Independent or Dependent sample

I am comparing whether Spot Gold prices and Gold ETF prices have the same performance. A spot price is the current price in the Precious Metals marketplace at which a given asset such as a security, ...
1
vote
1answer
25 views

Is non-sampling error included in hypothesis testing assumptions?

I understand that, in hypothesis testing, we are dealing with sampling error. We calculate the statistic from the sample data and test what the probability of getting that result is when the null ...
0
votes
0answers
11 views

Formula for Power of Upper Tail Sign Test

Given Consider the upper tail $H_0: \theta \leq 0 \,\,\, \text{vs} \,\,\, H_A: \theta > 0$ sign test with the test statistic $B = \sum_{i=1}^n{\psi_i}$ where $\psi_i = \mathbb{I}(Z_i > \theta)$...