Hypothesis testing assesses whether data support a given hypothesis rather than being an effect of random fluctuations or some other process described by an alternative hypothesis.

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P value distribution skew & hypothesis testing

On this page it says ...if HA holds, the p-values have a distribution for which values near 0 are more likely than values near 1. However the p-values may have a distribution that is not ...
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“Under the ANOVA null, within group and between group sample variance are both estimates of the pop. variance” — why only under the null?

In Statistical Methods by Snedecor and Cochran, it states something to the effect of "the within-group variance is an estimate of overall variance given the null hypothesis" and this point is used to ...
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18 views

Which statistical test to use with repeated measures & clustered observations?

I am doing experimental study for my research. I have class with 24 students and six groups, where each group includes 4 students. I want to compare the performance of each group in two cases: first, ...
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62 views

What statistical analysis did they do in this paper?

This is really a beginner question. I have to perform a statistical analysis which is exactly the same as the one conducted in the table shown in the picture. Specifically, how to calcolate the ...
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24 views

Can I say there would be only 2 groups with such features in this data and prove it using cluster analysis?

I assume that there would be two groups that will emerge within the data with my assumed features. I run cluster analysis and best number of cluster (elbow, dendrogram, etc.) shows it will be 2 and ...
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8 views

How to test adjusted mean in R?

I have got eight adjusted means for eight subgroups in a survey study, but I don't know how to test the differences of these eight adjusted means. Any suggestion is appreciated. Thanks!
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28 views

test interactions for multiple regression with many predictor variables

I have a data set with around 25 predictor variables. If I am planning to build multi-regression model against this data set. What are the general approaches to test the interactions of these ...
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13 views

Help finding critical on a hypothesis contrast

I´ve tried finding the variance using the moment-generating function but apparently that is not the correct method for finding the critical. Can you help me with this?
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8 views

Finding a hypothesis test based on the Neyman-Pearson about a parameter with a piecewise density function

I'm having trouble about how to start this problem. The density function for a random variable $X$ is: $$ f(x|\theta) = \begin{cases} \frac{1}{2(1+x-\theta)^2} & \text{$if x \ge \theta$} \\ ...
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15 views

Test equality of two measurements for a outcome

I have a binary outcome which were measured with two methods say A and B such a $2\times 2$ table like this: ...
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29 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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22 views

Statistical Test for Two-Alternative Forced Choice Task (2AFC)

I conducted a learning experiment and assessed whether participants learned with a two-alternative forced choice (2AFC) task consisting of 100 items (25 items of category 1, 25 of category 2, items of ...
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23 views

Number of possible statistical test can be used on the observation data.

I am working on research paper for diagnosis of cancer. List of Known prognostic factors Age of patient Size of tumor Grade of tumor Lymphnode involvement and list of Unknown factors which are ...
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36 views

Test for autocorrelation

I wanted to test if there's significant autocorrelation in my data. Here's the reproducible code(R!) and the result. It looks like that dwtest and bgtest and acf are all too much different. Can ...
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1answer
25 views

Three proportions testing null hypothesis

I have the following question. In a random sample of 250 people with low incomes, 155 are in favour of a new piece of legislation, while in random samples of 200 people with average incomes and 150 ...
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20 views

Chi square test with replicates

Is there anyway to do chi square (or any other ratio rest ) with replicates. For example, my data have measures of different time points, each time points has 4 replicates. The measures are discrete ...
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Distribution of large set of fold changes

My background in stats is limited to a few undergraduate classes. However, I have a question that intuitionally seems to have a statistical answer. Let me describe my intuition first. I do systems ...
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1answer
49 views

Why does a confidence interval including 0 mean the difference is not significant?

Could someone please explain why zero being inside or outside the confidence interval tells you whether or not the difference is significant?
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9 views

Hypothesis Testing with unidentified standard deviation [closed]

A survey found that the average communication of male is 35 and the average communication of female is 65. The data obtained from 100 students from 2 samples and that the standard deviation were _ and ...
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21 views

Is Wilcoxon test still valid if there is some shared information?

I have $N$ samples from a population, and to each sample I apply both method A and method B, recording the time each takes to run ($T_A$ and $T_B$, say) I then define a new pseudo-measurement for ...
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22 views

Correlation? Factors affecting academic performance of students based on their gpa? [closed]

My friend's thesis. just helping her with the data analysis "FACTORS AFFECTING ACADEMIC PERFORMANCE OF STUDENTS BASED ON THEIR GPA" Divided it into: Internal Factors: Class Schedule & parental ...
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49 views

Why is permutation test wrong with variance but correct with standard deviation?

I am trying to understand the limits of permutation testing. I wrote up a small permutation test example in R, and found that permutation testing seems to fail when using absolute difference in ...
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12 views

regarding the statistics to test the impact of some subset values on a given variable

For a given variable, there is a set of values. We know that these values can belong to different clusters. For instance, a lot of values center around a small value while other values center around a ...
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18 views

The way to evaluate the importance of an independent variable in a regression model

In a regression model, like y~( x1, x2, x3). Is there a test or a way to evaluate which independent variable, x1, x2, or x3, is ...
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1answer
14 views

how to evaluate consistency of rankings for n columns

Suppose I have n columns in a matrix (example below has n= 4). Is there a test I can check that the rankings over columns are ...
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1answer
35 views

hypothesis test for a boolean combination of alternatives

I have a student (for a high school project) who has conducted an experiment and collected data in the following (simplified) way: id|situation|scoreX|scoreY ...
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1answer
18 views

Comparison of multiple means using summarized data

I have means, variances, and sample sizes from three geographical sites but not their raw data such that: ...
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28 views

Is Bonferroni Correction Appropriate for this Analysis?

Suppose I have performed a study wherein I compare a novel intervention (N) against the standard intervention (S). Participants are assigned to N or S randomly, and the study is performed. There are ...
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1answer
23 views

How to present statistical significance results among more than two datasets?

Let us say that we have 5 sets of data: $$ a = (a_1, a_2, \dots, a_{10}) \\ b = (b_1, b_2, \dots, b_{10}) \\ c = (c_1, c_2, \dots, c_{10}) \\ d = (d_1, d_2, \dots, d_{10}) \\ e = (e_1, e_2, \dots, ...
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119 views

Low sample size: LR vs F - test

Some of you might have read this nice paper: O’Hara RB, Kotze DJ (2010) Do not log-transform count data. Methods in Ecology and Evolution 1:118–122. klick. Currently I am comparing negative binomial ...
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22 views

What criterion are used to accept/reject hypotheses in ridge regression?

On what basis might one accept/reject a hypothesis when running ridge regression? For example, if I have five predictor variables as part of a ridge regression... what criterion would I use to accept ...
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12 views

comparison of time values as response variable

The data set I have is a 12 subject Latin Square cross-over design with 2 periods (1 or 2), 2 sequences (AB OR BA) and 2 drug formulation treatments (A or B). The subject response variable is a time ...
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11 views

R Cramer Von Mises test

I am using the cramer's test in R using the "cramer" package. There are some options for the kind of Monte-Carlo-bootstrap or eigenvalue (ordinary, permutation and eigenvalue) and the kernel (Cramer, ...
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34 views

Which statistical test for women height?

Suppose women may have Blue or Red eyes. We make a first cheap research on a 100 women checking just one eye of each woman. So after the research we have results: At least one eye Blue have avg ...
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31 views

Variance decomposition time series hypothesis testing

I'm doing biological gene expression data. For the genes I analysed, each gene can produce two isoforms, one dominant (Gene isoform 1) one minus can be treated as a by-product (Gene isoform 2). I'm ...
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1answer
34 views

Big difference in p-value from permutation test

I have roughly 60 values of discrete temperature satisfaction votes ranging from 0 to 4. In the figure below I have grouped the votes depending on the daily number of hours the individual occupants ...
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1answer
23 views

Confused Beginner Question: Multiple simultaneous tests and signal pollution

The best way for me to explain the problem might be to just give an instance of our data and the type of test/conclusion I am attempting to draw. Unfortunately as the title suggests, my understanding ...
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7 views

Probability of type ii error of Pareto distribution

We are given the Pareto Distribution is of the form FX(x) = 1 − (1 + x)^(-1/theta) Earlier, it has been derived that the sample minimum from a Pareto function is also Pareto distributed, with ...
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15 views

Comparing treatment vs control for ordinal data, controling for potential confounders?

I am new here so bear with me. I have two groups, Intervention and Control. Patients have answered the question: How are your back problems now compared to before treatment? Much better, ...
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1answer
31 views

5% significance difference

I need help with this question please. To test the effectiveness of a diet 10 patients are placed on a diet for one month. They are weighted before and after the study. Their initial weight is ...
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1answer
59 views

Two sample Kolmogorov-Smirnov test for the stochastic dominance

I'm trying to use KS test to determine whether one group of data is scholastically dominates another. So I'm studying dataset regarding performance of companies, which are divided into 2 groups. ...
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1answer
30 views

Testing if a interval scaled variable A and a nominally scaled variable B are independet when A is not normally distributed

We have a variable A which denotes a percentage between 0 and 1. The variable is not normally distributed but has a very left skewed distribution. About 5% of the observations are zero, most ...
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3answers
70 views

Can I do a t-test to test significance? [closed]

I need a statistical test to determine if one group of ten classrooms with different numbers of students in each class has a class average on a test. Group two has 12 classrooms also with different ...
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10 views

Comparing goodness-of-fit across conditions

I have repeated-measures data. Participants complete both Stage A and Stage B (random ordering). I have two complex models, Model 1 and Model 2, which are fit using optimization techniques. Model 2 is ...
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1answer
26 views

A/B/C Testing - Aggregate data for comparison?

Let's say I have 3 ads: A, B and C. These ads perform as follows- ...
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2answers
55 views

Empirical rejection rate of a wrong null hypothesis -is it the “power of the test”?

I guess this is basic, but it forms part of the holes in my statistics education. What I know is that the power of a hypothesis test is not a fixed magnitude, but a function of various factors ...
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2answers
75 views

Goodness of fit (cdf: empirical vs theoretical)?

I have a data-set with n = 90, probably follows the gamma distribution (and others). I used the maximum-likelihood estimation (MLE) to estimated the alpha and beta parameters of the gamma distribution ...
3
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1answer
41 views

Hypothesis testing based on Likert type data

I know this site is full of similar questions, but either their answers do not apply, or I'm missing something. I have data from a questionnaire. Responses are in the form of Likert items, some of ...
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1answer
159 views

Unusual Terminology in Hartigan's DIP paper?

In Hartigan's DIP test paper, it says A distribution function $F$ is unimodal with mode $m$ if $F$ is convex in $(-\infty,m]$ and concave in $[m,\infty)$. Shouldn't that be a cumulative ...
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Determine if missing values are informative(due to treatment) or just noise.

I'm not sure if this is those appropriate way to phrase this question. I have two populations of measurements. In my control population I have a quantitative measure of a proteins abundance. I expect ...