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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8 views

Mixed-effect models for repeated measures - problems with the “Significance level”

I am trying to fit a linear mixed-effect model to my dataset to see the relationship between a self-reported questionnaire and some physiological data. I've created a first model including all the ...
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15 views

Test for difference of quantized distributions

I have a bunch of ratings, which are in the set {1, 2, 2.5, 3, 4}. I want to test the hypothesis that the ratings are different between two different populations. We can model these ratings as being ...
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19 views

Statistics: How to argue two number is significantly different from each other?

I have two groups and each group has equally four members. I assign each member equal score 5 in group A. I assign each member score 10 in group B. If I want to argue that the members in these two ...
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10 views

Similarity between two large vector

I have a two large/long vectors which I try to calculate the similarity between them. First vector: Length of the vector nearly: ~990 < ["RAB31", 25], ["SNAP25", 34], ["PCK2", 34], ["HMGCR", ...
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8 views

Significance test WEKA Experimenter. Same algorithm , different set of attributes

I would like to know if there is a way of doing a statistical significance test in Weka Experimenter between models obtained by using the same regression algorithm (M5Rules) over two different sets of ...
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1answer
17 views

Assessing correlation/similarity in shape and position of two datasets

I have data-sets within which position and shape (curves, relative increase/decrease at any given x-value) are the defining characteristics, such as: And a simulation which attempts to recapture ...
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0answers
14 views

Test for difference in a set of post hoc tests

I have calibrated an classifier with different sources of training data and I want to evaluate its performance with several data sets. I plan to use the Friedman test and post hoc Nemenyi tests to ...
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17 views

Determine significance of an observed continuous distribution given many randomly generated continuous distributions

Suppose there is a vector, v, that contains the body height of every person over 30 years old on earth. It looks something like this: ...
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14 views

Comparison of continuous two-dimensional state space grids across participants

Each participant completed k trials from which I obtained x and y coordinates describing a location on a Cartesian coordinate system (so, each participant has x$_1$, y$_1$, … x$_k$, y$_k$ ...
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36 views

What does it mean that coefficient is significant for full sample but not significant when split into two subsamples?

I have a sample of acquisitions 1994 to 2015. When I run an linear multiple regression with the cumulative abnormal return after the announcement my coefficient of interest (HFA_dummy) is statistical ...
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17 views

Statistic test for correlation among multiple variables || statistical test for confirming sales pattern among multiple items

While thinking about sales of a company, I came across a question. I have data like below: Day1 day2 ......day30. item1 10. 20. ....... 30. ...
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2 views

How do you determine if a self-report subscale is influencing the overall self-report score's significant relationship?

I'm running a series of independent samples t-tests with a self-report and its subscale scores as the dependent variable. Both the overall score and one of the subscale scores show signficantly ...
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29 views

Does practical insignificance mean no relationship?

I have two problems: 1) I have a regression coefficient that is very significant (large dataset), but has low practical significance. Can I say there is no relationship? And I mean really tiny, like ...
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21 views

Statistical significance testing over population

I have two data sets of 65 data points. I want to test the significance of the difference in distribution between them by Kruskal-Wallis test. But the data sets are not samples, they are the ...
3
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1answer
31 views

Random effects for second order in R mixed models

I am fitting a mixed effects model in R using nlme lme(y~x+I(x^2),random=~x|subject,data=train) Is this the correct way or should it be ...
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1answer
25 views

number of participants to have a 80% chance of detecting a 1.5% point difference as significant

Can someone explain how the math used to determine that 34 participants were required for this study? To have an 80% chance of detecting a 1.5–percentage point between-group A1C difference as ...
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6 views

Test for actual realisations

I'm performing binomial test to check whether the number of occurrences within buckets are not greater than 95%. I'm using R for that. ...
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13 views

Statistical test for relationships when many samples are unknown

I'm fairly new to statistics - I'm sure this is a basic question but my google searching is failing me. Happy to just be pointed to other reading. I have 3 datasets of varying sizes (N1 ~ 200,000, N2 ...
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1answer
15 views

8 variables for 12 months. Sigmaplot

I have measeured 8 variables for 12 months. n = 5-20. So, now I have mean, STDEV, SEM and n for those variables. I have trying to show relationship within those variables and among months. So, I ...
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9 views

Statistical test between pairs of values recorded by human and machine inorder to find the agreement between them

I have a set of independent values (which are subjective) recorded based on both human observation and machine recorded ones. At this point I want to ask serval questions like what is the agreement ...
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21 views

When to scale or standardize data in regression

Many statistical software ask whether to standardize data or no: What is a general rule to when data should be standardized? Do we standardize categorical variables? Is there a difference in how ...
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20 views

Bivariate Poisson regression and Pythagorean Expectation for soccer(football) [on hold]

based on public data and using excel 2010 or after, I want to forecast/predict the football match winner.
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18 views

What statistical test should I use in this situation?

Say I am sampling fish from a reach of stream (a set distance). I sample three distinct habitat types (same distance each) within this reach to calculate a score for the site (each habitat recorded ...
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24 views

Calculate Cronbach's alpha for three observers

I have a dataset which contains 100 observations, and I asked three expert to describe each observation by one of the letters {A,B,C}. The following three tables shows a sample of the dataset with the ...
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1answer
48 views

Which statistical test to use

I have a table containing, for each patient, the count of synonymous and non-synonymous mutations in primary vs metastasis (total 20 patients) like the following. 1P 1M 2P 2M 3P 3M 4P 4M ... ...
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1answer
33 views

Main Drawbacks of stepwise regression

People typically prefer the Lasso or other methods to stepwise regression. What are the main problems in stepwise regression which makes it unreliable specifically the problems with forward selection ...
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11 views

Performing two-sided F-Test [duplicate]

Due to the asymmetry of both the Chi-Square and F distributions, is it still possible to perform a two-sided test? From this answer it seems that you can only ever perform a one-sided Chi-Square test: ...
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33 views

Influence of categorical variables on continuous outcome

I have a dataset of independent samples where we investigated whether an outcome variable 'TTI' was affected by four levels of relative humidity combined with two levels of oxygen. TTI does not seem ...
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24 views

Correlation test over time

For my research I want to test whether the influence that certain variables have on compensation, have changed over time. The influence of this variables are measured by looking at the correlation. ...
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0answers
18 views

Clustering, reducing number of levels of categorical variable

I'm dealing with this big dataset which has: 1 categorical variable with 90 levels that represent some sort of "geographical area" 3 continuous variables What I'm trying to do is to "aggregate" ...
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9 views

Question about the EFA model

Then, my supervisors suggested me to run EFA for the model but it ended up the items in the same group were being distributed to different groups, where the grouping of those items doesn't make sense ...
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22 views

Friedman's test or Monte Carlo?

I have two time-series data sets of the same five experiments. That makes two 5 X 7 matrices where the row is the experiment and the column is the day, and each matrix comes from a different ...
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15 views

Using Mahalanobis Distance as Dependent Variable

I would like to know whether Mahalanobis Distance can be used to substitute dependent variable and bring about statistically significant model. Basically, I tried to regress a model using OLS ...
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14 views

Comparing algorithms: runtime vs accuracy

I am comparing several algorithms with respect to their runtime and accuracy on several datasets. I follow [1] and compute the average rank using the accuracy and apply the Friedman and Nemenyi tests. ...
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1answer
39 views

How to determine if two means are equal?

I'm a student in AP Statistics and our end-of-year project has me stumped on one small aspect. The variables here aren't the ones in my project, but it'll make it easier to explain. I'm trying to ...
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3 views

Significance test for relative rating scale

I have developed a program that provides output for a task. I would like to show that my results are preferred over those of another tool (with the same input). I have run an evaluation where ...
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0answers
21 views

non-trivial coefficients in an OLS regression

I have a problem explaining how and why the coefficient on my regressions is changing signs. I have a continuous outcome variable Y which is a linear combination of two continuous variables y1 and ...
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1answer
39 views

When confidence intervals of two parameters do not overlap with the mean of the other, why is it considered to be statistically significant?

Consider two parameters with means A and B with 95% confidence intervals. If the confidence intervals of the parameters do not overlap with the mean of the other, why is it considered to be ...
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19 views

Event Study - Event Induced Volatility for One Firm

Normally, in a stock price event study, we assume that the daily variance in the estimation period is the same as that during the event window. The event-induced volatility literature (eg, Boehmer, ...
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31 views

Modeling distributions

Suppose I am studying a unimodal, interval-leveled variable $Y_i$ that measures e.g. individuals' positions on a (-$\infty$,+$\infty$) continuum. Then, I noticed that for different sub-categories of ...
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28 views

68–95–99.7 rule for binomial distribution?

What I want to calculate is the probability that the size $k'$ of an intersection of two subgroups with sizes $n$ and $K$ that have been randomly selected from a group with size $N$ that is smaller ...
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19 views

Dummies with different significance

A friend asked me this question to which I cannot answer: he is running a linear regression and he has 3 categorical independent variables which, if used altogether, would give multicollinearity. If ...
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1answer
24 views

How to estimate the likelihood that a distribution is not random

Not sure I phrase the title right, but here's by question in a nutshell. Say you have a box of balls with different colors. Let's say there are $N$ balls of $k$ different colors, and that the ...
2
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1answer
31 views

Confidence intervals and standard error for binary data/proportions

I'm doing some research into degrees held by professionals of different types, based on survey data. I'd like to be able to provide confidence intervals for some of the subgroups of professionals as ...
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0answers
16 views

multicollinearity and signficance confused

If explanatory variables are correlated, what is it have to do with some being individually insignificant or significant? What is that supposed to mean? If adding additional variable causes other ...
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1answer
24 views

Weight or impact of variable in correlation

Consider I've have two curves (catgeory1,category2) that are strongly negatively correlated( -0.88). for 1, I've few sub-category (o,p,q,r,s,t,u,v,w,x,y,z). I want to know the weight of each one in ...
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5 views

Significance Test in Filtering

I have N worker scores, which are the results of how well they did on a single task, and a criteria that dynamically filters (ie. removes) some of the workers from this dataset. On average, roughly ...
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0answers
18 views

Estimates for a subset of observations : how to proceed

Please note that I don't know the name of what I am trying to do, so maybe there is a lot of theory on it, or questions I couldn't find. I am trying to estimate the value of a parameter in my model ...
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26 views

A/B Testing: Is it necessary to test old versions every now and then?

Recently I was talking to a coworker about A/B Testing -- we run a variety of A/B tests on our website and the thought of doing a "back test" was mentioned where we essentially restore an old design ...
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1answer
35 views

F statistic vs T statistic

I have a variable that I can divide to 3 groups: A, B, C. I want to check if the difference between the groups is significant. Should I use F-STATISTIC or maybe T-STATISTIC of each group vs. the other ...