Statistical significance refers to the probability that, if, in the population from which this sample were drawn the true effect were 0 (or some hypothesized value) a test statistic as extreme or more extreme than the one gotten in the sample could have occurred.

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The performance of 50 teachers in the English Department showed a mean of 98 with a standard deviation of 9.2. [on hold]

The performance of 50 teachers in the English Department showed a mean of 98 with a standard deviation of 9.2. A sample of 40 teachers from the Mathematics Department showed an average performance of ...
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20 views

main effect and interaction effect

I faced difficulty with my data analysis output. I had two factors with split plot design. Separately, the main effect of the two factors on soil pH was significant. But their interaction effect was ...
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9 views

How to calculate whether a change in expenditure is statisically significant

Sorry, this is probably very basic... I have data on expenditure over 3 years. This expenditure is made up of 2 products L and H. L has been increasing and H has been decreasing, so overall L+H is ...
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4answers
288 views

Is the “hybrid” between Fisher and Neyman-Pearson approaches to statistical testing really an “incoherent mishmash”?

There exists a certain school of thought according to which the most widespread approach to statistical testing is a "hybrid" between two approaches: that of Fisher and that of Neyman-Pearson; these ...
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1answer
12 views

Non-response bias (many waves, time span between waves not consistent)

I want to ask regarding non-response bias. I have sent my questionnaire on-line to SMEs in Malaysia. However, I have sent reminders many times (around 5 times). However, now I cannot recall when the ...
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12 views

Correcting for multiple testing on non-independent sliding windows

Question Values taken from adjecent windows in a sliding windows are corrolated. If I calculate a p-value from each window, how can I correct for the fact I have tested many windows, given that the ...
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2answers
40 views

Confidence intervals which contain 1 but the z test and p value are significant

I calculated the confidence intervals for the regression coefficients using the formula: SE X 1.96. I then took this value away from the regression coefficient to get the lower confidence level and ...
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0answers
10 views

How to down weight correlations in my microarray analysis?

Background: I have been tasked in one part of my analysis to reproduce a method used in another study as follows in bullet points form: Microarray data from a number of time points Calculate ...
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1answer
66 views

How can a regression be significant yet both predictors be non-significant? [duplicate]

I know this question has been asked in a slightly different form here. But my question differs and because of the forum rules I can't post on that thread. I have 2 independent variables, n=32, highly ...
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1answer
56 views

High Standard Deviation for Leave one out cross-validation?

I am using the leave one out cross-validation technique to evaluate my model. If the prediction on the test sample is right the output is 1 otherwise 0. So I have a array of N samples with 0's and 1's ...
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0answers
24 views

$J$ statistics to $p$-value of $J$ statistics an vice versa

I am not entirely sure if I should ask this question here, but does EViews has a function of converting J statistics to p-value of Jstats, or other way around. I am running several GMM estimations ...
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0answers
9 views

How To Determine Association Plot in R and p-value

I have created a contingency table and an association plot in R and I am not quite sure how to interpret it. Here is my contingency table: ...
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16 views

How to perform multilevel interaction

I have 400 observations = 100 individual * 4 years. Which equation is correct? $$x_{1} + x_{2} + \left(x_{1}x_{2}2013\right)+ \varepsilon$$ $$x_{1} + x_{2} + \left(x_{1}2013\right) + ...
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0answers
14 views

Statistical test Comparison of

I have some ordinal data (no. of exits from opiate treatment, by type (planned unplanned exits etc.). I want to know if last years figures have a statistical probability of being different from ...
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0answers
21 views

Bootstrapping results for p-values of trading rule profit significance

I want to obtain p-values for the significance of trading rule profits as described by LeBaron and Brock (1992). The author's use what is developed by Efron (1973) called Bootstrapping. It goes like ...
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0answers
19 views

Measure difference in answers on survey depending on item response options

For my thesis I sent out a questionnaire that has 10 questions. I set defaults: the first seven question had the default set to the desired answer and the last three questions had the default set to ...
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0answers
41 views

How to obtain t-value for significance of median

I collected analysts’ forecasts and calculated bias and accuracy such as: $bias=actual-forecast$ $accuracy=abs(actual-forecast)$ What I am wondering is now on how to calculate the t-statistic to ...
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0answers
14 views

Comparing 2 classifiers with different feature vectors based on same training and test data

Let us assume we have two classifiers C1 and C2 which are based on different feature vectors, ...
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0answers
13 views

3 way mixed ANOVA & pairwise comparisons effect size

im in desperate need of some help for my data analysis assignment! I have a 3 way mixed anova- where I have 2 sig main effects, one significant two way interaction and the sig three way ...
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1answer
33 views

Using a binomial approach to calculate significance of multiple significance tests

I have 10 data sets with normal distributions and carrying out significance tests on each one. With this many data sets, there is a good chance that some will be significant by chance. I am going to ...
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14 views

Comparing two paired data sets

I am trying to see compare tow paired data sets which do not have normal distributions, and I am not sure how to do that. Can I use t-test? I would appreciate your help very much. This what they look ...
2
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1answer
33 views

What are the relative merits of testing significance of a regression coefficient

If I have several hundred coefficients generated by running multiple variable regression model (keeping it as broad as possible by not specifying the nature of the predictors and outcome variable), it ...
2
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2answers
52 views

Which property of count data make mean-variance dependency?

I have read about the fact that, there is dependency of variance on mean of count data.In most of cases they do variance stabilization transfomration as preprocessing step of data modeling. I wonder, ...
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0answers
12 views

How do I perform a statistical analysis on an intervention based study?

I am trying to get my head around the best way to analyse a study. The study comprises of persons that get given a number of up to 10 different interventions, whereby hospital admission frequency is ...
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32 views

Test means of populations with lots of zeros, is sampling the way to go?

I am trying to test whether means of two populations with lots of zeros are different. Here is the following python code example: ...
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0answers
65 views

MHT: Pre-Selecting statistical tests without Bias

Summary: The last formula boxed in red (which is a modified log likelihood from logistic regression) is a special non-differentiable loss function that is adapted to contain a Bonferroni correction in ...
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5answers
200 views

Does $r$-squared have a $p$-value?

I seem to have confused myself trying to understand if a $r$-squared value also has a $p$-value. As I understand it, in linear correlation with a set of data points $r$ can have a value ranging from ...
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32 views

compare strength algorithms across different data sets

Reflecting on this paper. The use of a statistical significance test is required in order to compare the algorithms across different data sets. In that paper and other papers, the number of data ...
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12 views

are the percentage differences significantly different from oneanother?

morning, say i have 5 wheat varieties undergoing 2 treatment. when counting the seeds of the replicates the percentage difference between the means of the 2 treatments is 10% for variety 1, 30% for 2, ...
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1answer
21 views

Statistical tests

Can someone please explain the difference between difference test and correlation test? I am confused because e.g. if a mean of one group (males) is significantly different from the other (females), ...
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3answers
39 views

How to test if the change in difference between 2 distributions is significant?

I have 2 different conditions of 'behaviour state' and 2 different people. I'm trying to find a way to test if the difference in distributions (which I'm assuming are approximately normal) changes ...
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0answers
15 views

Non Significant MANOVA but significant OLS regression

I have data which is showing a $p$-value of $0.15$ significance value within a MANOVA (including a significant planned contrast). However, when I dummy code and put it into an OLS regression, the ...
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1answer
46 views

Finding distribution function [duplicate]

Let $X_1,X_2,...$ denote iid random variables such that $X_1$ is continuously distributed with density $p(x)$ and distribution function $F(x)$ where $F(0) = 0, F(x) > 0$ for all $x > 0$, and ...
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2answers
27 views

Comparison between Two Groups

One of my demographic variable is age. Age is measured as continues data not categorical. If I want to test differences between two groups to determine whether there is significant difference between ...
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0answers
13 views

Response Rate in Research

I want to ask about response rate. I have distributed 2500 posts. However, I have received back around 30. Then, I sent 200 posts as reminders with appealing letter. I have received one or two only. ...
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0answers
36 views

Inference test when data points are means

General background I've administered two types of questions to students multiple times. Type 1 I've administered six times, and type 2 I've administered five times. The two questions get at the same ...
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0answers
24 views

Chi-squared test with scipy: what's the difference between chi2_contingency and chisquare?

I'd like to run a chi-squared test in Python with scipy. I've created code to do this, but I don't know if what I'm doing is right, because the scipy docs are quite sparse. Background first: I have ...
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3answers
91 views

Is Maximum Likelihood Estimation (MLE) a parametric approach?

There are two main probabilistic approaches to novelty detection: parametric and non-parametric. The non-parametric approach assumes that the distribution or density function is derived from the ...
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0answers
44 views

Statistic for count process and measurements

I am facing some problems concerning which statistical approach to use for my measurements. I have a sensors which counts how many times an events occured. I had to characterize two lots of sensors, ...
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0answers
11 views

Motivating likelihood ratio test vs Wald test for paper reviewer

I've got back reviews for a paper I've submitted, with the following problem. I have two logistic regression models, say y ~ A, and y ~ A + B, where B is a factor with several levels. I have ...
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1answer
34 views

Find significance level of hypothesis

I'm given two random sample datasets of sample size n=20, where the first dataset represents the weights of random boys, and second group represents weights of random girls. I need to find the ...
2
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1answer
19 views

Multiple-sample z-test for proportions

Let's say I want to do a multiple-sample z-test for proportions. Is there any way to rank them? How would I compare more than two samples at once?
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35 views

ANOVA to find subjects that responded significantly different between treatments

I have a dataset composed of several subjects exposed to two different treatments (treat) in three distinct times (test), and I am interested in highlighting which subjects have significantly ...
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2answers
50 views

Significance factors

How can I determine a significance factor? For example, If 1/1 samples returns positive, the ratio is one. However, if 9/10 samples return positive, the ratio is .9, but is better because of the ...
4
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2answers
50 views

Does $\Pr(\text{Type I error})$ ever not equal $\alpha$ with continuous data?

This question: Comparing and contrasting, p-values, significance levels and type I error cites exceptions that arise when using discrete data. Are there other exceptions with continuous data as well?
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2answers
66 views

Examples for Type I and Type II errors

I was checking on Type I (reject a true H$_{0}$) and Type II (fail to reject a false H$_{0}$) errors during hypothesis testing and got to to know the definitions. But I was looking for where and how ...
2
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1answer
23 views

Assessing whether differences between datasets are significant

I am unsure which statistical test I should use to test whether two datasets are significantly different. The data looks something like this: ...
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1answer
101 views

$t$ test vs $\chi^{2}$ once sample is split into two groups?

I would appreciate some guidance regarding the use of a t test vs $\chi^{2}$. I am looking at some small set of demographic data (n only 13). I have divided up the sample into two sets, those with ...
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1answer
41 views

Beginner question: finding correlations with percentage data

I am trying to work out whether mobile, desktop or tablet users are more likely to perform an action on a site. The data I have is structured as follows: ...
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1answer
49 views

Non-significant factors after stepwise regression [duplicate]

I have run a stepwise regression on R. However, the summary of the final model includes some factors that are not significant. Why have these factors not been removed? Should I remove these from my ...