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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LR test for proportion of unknown constants

$X_1,...,X_n$ are nonnegative r.v. with hazard function $\lambda(x)= \left\{ \begin{array}{} \lambda_1 , x\leq x_0 \\ \lambda_2 , x>x_0 \end{array} \right.$ With ...
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21 views

Is this method of finding the confidence interval correct?

Suppose that we have 2 sets of data $X = x_1, \dots, x_n$ and $Y = y_1, \dots, y_m$ and a test $T$ that tests the null hypothesis that these data come from a distribution with the same median. $T$ can ...
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1answer
29 views

What exactly does a Type III test do?

I'm having trouble understanding what exactly Type III test statistic does. Here is what I got from my book: "Type III" tests test for the significance of each explanatory variable, under the ...
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2answers
82 views

Two-Sample t-Test for Equal Means with unequal variances for large samples

How can I perform a two sample test of means with unequal variances for a very large sample in R? In case of large samples the statistic will asymptotically follow a normal distribution. Which R ...
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1answer
17 views

Out-of-sample vs. test set

Someone asked me if I did out-of-time testing (which I assume is just out-of-sample testing but with a timeline element). But if I have a test set, is that not essentially the same as out-of-sample ...
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6 views

What does “(scores mapped into 1:m using rounded scores)” from the 1-sample permutation test mean?

I'm trying to do an exact paired permutation test. What does this "mapping" mean? ...
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34 views

What statistical test(s) should I use for this kind of repeated measures data?

Assume I have this kind of data: $ A_{11}\quad A_{21} \\ A_{12}\quad A_{22} \\ A_{13}\quad A_{23} \\ B_{11}\quad B_{21} \\ B_{12}\quad B_{22} \\ B_{13}\quad B_{23} \\ C_{11}\quad C_{21} \\ ...
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15 views

How to find weber fractions from a confusion matrix

I have a confusion matrix for a 4 class classification problem which looks this: My hypothesis is that group 3 is easiest to classify. Somebody suggested me that I can find weber fractions from this ...
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15 views

How to evaluate 4 methods with 4 possible outcomes

I have a table that looks like something this: Outcome Method 3 2 1 0 1 x_11 2 x_21 .... 3 x_31 4 x_41 x_44 Each x_ij ...
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2answers
35 views

Obtaining error bars for a difference

I have a pair of data sets, and I want to know whether the medians of these two sets differ significantly. I've calculated the median of each set and subtracted them from each other. How can I ...
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17 views

Set hypothesis instead of point hypothesis [duplicate]

Statisticians are often interested on testing point null hypotesis, such as: $$H_0: \mu =0 \,\,\, vs. \,\,\, H_1:\mu\neq0.$$ As Jeffreys himself said, this actually corresponds to some presumption ...
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24 views

Test for two confidence intervals

I would like to know if there is a test for the difference of to means m1 and m2 (continuous variables) if I have only information for mean, 2.5%- and 97.5%-quantiles. For example: $m1 \ \ \ = ...
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1answer
25 views

Using empirical null distribution to adjust odds ratios

I am doing a case-control study analysis with 2500 cases and 2500 controls. I am interested in finding out if the cases have higher odds of having a particular disease than the controls, so I am ...
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0answers
8 views

How to do mean comparison with trending data?

A client with a website has recently released a tablet app. The theory is that after installing the app a customer is less likely to log on to the website as they will use the app instead. For each ...
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2answers
208 views

What statistical techniques to use to distinguish between two groups?

I have a dataset of about 300 people. 200 test positive for a disease, and the rest test negative. I have data on different test scores and imaging results for these 300 participants. So my dataset ...
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5 views

Comparing observed Vs predicted window overlap/intersection

I have a large number (~1.5 million) of protein sequences, each of them of different lengths.There are 6 schematic examples in the attached image. Within each of these sequences, there are >= 0 ...
4
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1answer
173 views

Test that two normal distributions have same standard deviation

I have two normal distributions, and I want to test whether they have the same standard deviation, I really don't care about the mean. My idea is: de-mean both of them and then use Kolmogorov-Smirnov ...
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19 views

Statistical testing against empirical density function

I have a feeling this is a somewhat common problem but reading about tests for normal distributions hasn't really helped me as their assumptions didn't seem to fit mine. Consider the following case: ...
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1answer
52 views

Choosing cutoffs in examining the Poisson distribution (an application to prime numbers)

I have observed a number ($n=6$) of events and want to test the null hypothesis that they are Poisson distributed with a known parameter $\lambda\approx1$. But I don't know exactly when I started and ...
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1answer
25 views

Assumption for valid hypothesis testing of the OLS estimators in the small samples

Please support me solve this question: In a simple regression model y = b0 + b1*x + u we have the five main assumptions 1 linearity in parameters 2 random sampling 3 zero conditional mean 4 variation ...
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1answer
20 views

Is there a significantly different number of people between groups?

How do I estimate whether a given number of people across groups (say, 72 people in group 1, 95 in group 2 and 70 in group 3) significantly differs from a random distribution of people across groups? ...
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1answer
32 views

Is machine learning useful for comparing test group and control group

If you do a hypothesis to test the effectiveness of a treatment, or a marketing campaign, you want to be sure that the two groups are comparable. You can compare some relevant quantities between the ...
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16 views

Two-tailed test [duplicate]

In one-tailed test , we give our decision at $\alpha$ level of significant. But in two-tailed test , why do we give our decision at $2\alpha$ level of significant? Why do we not give the decision of ...
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18 views

Am I using Fisher method correctly?

Suppose I want to test the hypothesis that speed of light is always below $c$ (note: regardless of the medium). [Also, this is just a fake example, so pretend we don't know any physics theory] Now, I ...
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1answer
29 views

Durbin Watson test statistic

I applied the DW test to my regression model in R and I got a DW test statistic of 1.78 and a p-value of 2.2e-16 = 0. Does this mean there is no autocorrelation between the residuals because the ...
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44 views

Birthday “Paradox” — with a different perspective

Background: Many people are familiar with the so-called Birthday "Paradox" that, in a room of 23 people, there is a better than 50/50 chance that two of them will share the same birthday. In its more ...
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Statistical test needed for a pre-experimental study [closed]

Hi I am doing a pre experimental study with one group. what all statistics I need to do for the confirmation of the results? i need to know the inferential statistics which has to be done for this ...
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18 views

Test similar to Kruskal-Wallis test but for multidimensional vector

I need to do the similar kind of test as Kruskal-Wallis test, but for a multidimensional vector. Would you please kindly suggest such kind of test or provide some references for N-dimensional case
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20 views

inference Single sample [closed]

Can someone Answer this question. Thanks in advance. 6.17 the one with black circle. Right now i have no idea how to approach and solve it.Any help would be highly appreciated. Thanks.
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42 views

Statistical Significance or Unambiguous Direction of Influence?

TL;DR In the context of a linear regression model, we run a statistical test for whether an estimated coefficient is "statistically significant". We will say that it is if we reject the null of ...
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40 views

What are the null and alternate hypotheses? Will you use a left, right, or two-tailed test?

Ben has a coin which he claims is weighted in a way so that when he flips it, heads appears more often than 50% of the time. He tries to prove it to you by flipping the coin 100 times, which ...
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1answer
26 views

How to evaluate a statistical test for fairness of a coin?

I suspect that a given coin is not fair, i.e that the probability of heads is not $\frac{1}{2}$. My question is not how we can prove the unfairness, but if we derive a test to check the fairness, How ...
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639 views

Why does frequentist hypothesis testing become biased towards rejecting the null hypothesis with sufficiently large samples?

I was just reading this article on the Bayes factor for a completely unrelated problem when I stumbled upon this passage Hypothesis testing with Bayes factors is more robust than frequentist ...
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17 views

How to compare the nested models which each of them comes from diffrent dataset?

I have four nested models.Every of them learned from different data sets. now I want to compare these models together.normally people try to compute the F-satistics. But for my case, it's bit harder, ...
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19 views

Number of significant linear predictors if predictors are not independent?

I would like to determine which of a set of candidate predictors $\{x_1, x_2,\ldots, x_n\}$ are significantly relevant to the linear prediction of $y$. Typically, one can compare a full model ...
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1answer
38 views

Comparing coefficients of two variables: one is significant, the other is not significant

I'm trying to test whether the coefficient for one independent variable ($X_1$) is larger than coefficient for another variable ($X_2$) in predicting the dependent variable ($Y$). For example, my ...
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9 views

Comparing file sizes day on day for outliers, what test to use?

I am quite new to statistical analysis, and have to crunch through several thousand folders/files each day to, at a first glance, see if the file size indicates an error (too large/small etc). The ...
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1answer
23 views

Statistical significance in binomial variable: how many tests needed?

I have a problem that occurs randomly, in approximately 2 % of tests. I am testing fixes, to prevent the error from occurring. The error occurring once would mean it is still happening and would ...
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3answers
86 views

Is binary hypothesis testing a better statistical term than A/B testing?

Is binary hypothesis testing a better statistical term for what business intelligence often refers to as A/B testing? Wikipedia suggests that this is the term used withing the statistics community but ...
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6 views

Testing dispersion of values between condition on a group

I may have a tricky question. I have a within design where every participant is tested in 2 conditions. I want to compare the dispersion of the measure, for the two condition, with the hypotheses that ...
2
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1answer
75 views

Does one group respond differently from others

I'm looking for the best way to test the hypothesis that two groups are different considering the relationship between two variables. There is a population of individuals and, for each individual ...
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0answers
8 views

Confidence size and coverage probability in a confidence set?

Let $\theta \in \Theta \subseteq \mathbb{R^d}$ be the parameter of interest and let $\theta_0$ be the true population parameter value. Let $n$ be the sample size. Let $CS_n$ be the confidence set ...
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0answers
20 views

R - power.prop.test, prop.test, and unequal sample sizes in A/B tests

Say I want to know what sample size I need for an experiment in which I'm seeking to determine whether or not the difference in two proportions of success is statistically significant. Here is my ...
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8 views

Joint test for absolute value of a mean [duplicate]

How can I test than the mean of a variable is greater than or equal to -3 and less than or equal to 3? In other words I want to test if the absolute value of the mean is less than or equal to 3. ...
4
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1answer
47 views

Significant difference between proportions, found at sample size below that suggested by power analysis

I'm looking at data from experiments that have been run to look for a difference between proportions, 1-tailed. In many of these it has been found that there is a significant difference between the ...
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0answers
6 views

Comparing IRFs derived from Bayesian VARs with other extraneous information

I was wondering if anyone here could help me with the following: I estimate a standard Bayesian VAR with Normal-Inverse Wishart priors. I identify some policy shock in it, and then derive the IRF for ...
3
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1answer
46 views

Are significance tests only about sampling error or other forms of variation also?

When we study differences between a treatment and control group in an experimental setting, we want to test whether those differences are big enough that we can conclude they are not simply due to ...
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2answers
177 views

Comparing performances during a race between 2 groups, which test should I use?

Imagine I organized a race between 2 types of ants. Type A and B. At the end of the race, I have the ranking, which looks something like : ...
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2answers
244 views

Interpreting one- and two-tailed tests

How do you report results that give you a p-value of 0.08 for a two-tailed test and a p-value of 0.04 for a one-tailed test? Generalizing the issue, if you obtain a p-value between 0.05 and 0.9999 ...
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21 views