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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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What statistical test to use if analyzing the effect of brands of Soda on their phosphorus content?

As explained in the title, I was wondering what kind of statistical test one should use to analyze the phosphorus content of different brands to see if there is a meaningful statistical difference ...
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Testing nested models with clustered errors

I have a simple linear model. $$Y_i = \beta_1X _{1i}+ \beta_2X_{2i}+\beta_3X_{3i}+\epsilon_i$$ I'd like to test if some of my model parameters ($\beta_2$ and $\beta_3$) are jointly different from ...
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Sample mean outside of 95% confidence interval but not significant at alpha=0.05 [duplicate]

Sample 1: n=960, mean=815.82, s=305.42 Sample 2: n=23, mean=887.02, s=186.02 I am testing whether the mean of sample 2 is different to sample 1. I generated the 95% confidence interval for sample 1 ...
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How to compare sub-sample mean with the sample mean?

I have a dataset with 983 rows and two columns: Rent and Postcode. The mean Rent for the entire sample (983 rows) is 817.49. The mean Rent for the N1 postcode (23 rows) is 887.02. The N1 data is a ...
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11 views

T-test - sample test - group statistics. Can I make a conclusion of this if my sig (2-tailed) is not significant? [on hold]

my hypotheses were 1) lower comprehending score for living out of the home, 2) higher distancing score for living out of home. The group statistics do show that my hypotheses were right but the ...
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11 views

Test for difference in absolute means, while accounting for full range of variability (+ & -)?

I need a statistical test for whether there is a difference in expected means between two samples, A and B, on the absolute scale, i.e.: Null hypothesis: |E(A)| = |E(B)| A & B are measures of ...
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How do I interpret this result - Correlation not significant except the relationship between Distancing and comprehending [duplicate]

My hypothesis was 1) higher comprehending score associated with older age 2) No relationship between distancing score and age My teacher did the SPSS part so I'm not exactly sure if this supports my ...
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16 views

T-test - (2-tailed) is not significant? What conclusion can I make from this table? [on hold]

My hypothesis was: 1_ Higher comprehending score for mothers vs fathers 2_ No difference on distancing score for mothers vs fathers My teacher did the SPSS part so I'm not exactly sure if this ...
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12 views

How to test for significant correlation while controlling for sample size?

Creating a SLR model and performing a t-test on the slope parameter (or doing an F-test on the sum of squares) greatly depends on the sample size. I am dealing with very large sample sizes, so small ...
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15 views

Statistically evaluate difference between time series [duplicate]

I have two time series. I want to evaluate if two time series are different enough in one window or space of time. The objective is to trigger an alert when one time series divert significantly from ...
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24 views

F statistics and relative significance

I have some f-statistics that came from an ANOVA (1 df in numerator and 60 df in denominator) : (first row should be labeled "H," second row labeled "S.") ...
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Negative Values in G test

I have a question, that regards the G-Test. This, as defined by Wikipedia to use $$ G=2 \sum \limits_{i=0}^n O_i\ln(\frac{O_i}{E_i}) $$ as a value to measure the observed samples $O_i$ of category $...
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Significance test for Yule's Q

It says here that the test statistic for Goodman and Kruskal's gamma is $z=G\sqrt{\frac{n_c+n_d}{N(1-G^2)}},$ where $n_c$ and $n_d$ are the numbers of concordant and discordant pairs, resp. ...
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13 views

Hierarchical multiple regression and importance of individual predictors across multiple analyses

I'm currently reading an empirical study using regression and want to determine whether to consider it a trustworthy, well-analysed piece of literature. I'm more familiar with ANOVA models, so I was ...
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9 views

Which bivariate analysis to use for determining significance in predictors between two groups?

I'm conducting a "typical" statistical analysis in my research, but I have a few questions regarding appropriateness of the tests I'm using and whether or not I'm doing things the correct way. I don't ...
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26 views

Compare two sigmoid shape curves

I have x and y-values for two sigmoid curves (probit). x-values are the same for both curves,...
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35 views

T-test - sample test - group statistics. Can I make a conclusion of this if my sign (2-tailed) is not significant? [on hold]

my hypotheses lower comprehending score for living out of home, higher distancing score for living out of home The group statistics does show that my hypotheses were right but the sample test is not ...
0
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1answer
21 views

Testing Statistical Significance for two different groups that were surveyed

What is the statistical significance test that should be run to see if the results from a smaller group of those surveyed is significant and reflective of the larger group? For instance: 1. Survey ...
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17 views

Does p-value (significance) function follows a cumulative distribution function (CDF) for every fixed sample $X$? [closed]

Let's consider a one-sided hypothesis test $H_{0}:\theta \leq b$ vs $H_{1}:\theta > b$, for a given $b$ in the parameter space $\Theta$. Now the p-value function is, P - value function $p_{n} = p_{...
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P-values: a misconception? [duplicate]

Statement: The lower the p-value corresponding to some test statistic, the greater the evidence against the null hypothesis. I see this statement everywhere, I would argue that this statement is ...
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6 views

Proximity Matrix in Hiearchical Clustering

I have a proximity matrix from a hiearchical clustering calculation. I have used the Pearson Correlation as my distance metric. Is it valid to test the statistical significance of this value using a ...
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32 views

Maximum significance level

What is the maximum significance level that the null hypothesis is not rejected? How do I calculate it? Context: The weight of a plate is a normally distributed variable with μ=330 gr. and standard ...
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1answer
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Combining P-Values from multiple trials of the same experiment

this is my first question here, a little background about me, im a biomedical engineer, im studying a PhD in Neuroscience, and a Micromaster in Statistics and Data Science. Here in my lab, very few ...
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significance testing of unequality of coefficient of variation in multiple samples

I'm performing a study on inter-doctor variation. For that, I'm studying a diagnostic instrument that has around 100 items that all have to be rated. Some are dichotomous, some ordinal. Several ...
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16 views

Different significance in GLMM interactions

I am confused about different significance results obtained in GLMM's. First, my set of relevant variables: ...
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22 views

Comparing two computer generated datasets

I have created an artificial stock market where different groups of traders trade with each other and therefore influence the asset price as well as the returns on the asset. The model generates 10k+ ...
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16 views

How to compare 4 different time series and check for statistical significance among them?

I have a data comprising the proportion of a certain bat behavior across nights from 1800h to 1930h. I want to compare and check whether there is a difference in the behavior with 4 varying moon ...
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15 views

Why statistical model significance test seldom seen in feature selection of Machine learning?

Background What I learned from the regression class in statistics told me that in order to remove a feature, or several features, we need to run a statistical significan test by checking the $F$-test ...
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Statistical test for categorical and numerical variable

Let say that I have this table that shows the number of time spend for each attribute in different location: ...
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Interpretation of a hypothesis.

suppose If I hypothesize that "a" have a negative relationship with "b". The resulting path coefficient is significant with 99% confidence interval but with positive beta or a positive relationship. ...
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How to test if a change in conversion rate (trended month on month) is statistically significant?

I keep getting asked at work to diagnose changes in conversion rate (month on month trend) even when the changes are only a few percentage points - either up or down. Conversion rate across our ...
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How to calculate whether a disease outcome in a population is by chance or significant?

I have a huge dataset of longitudinal medical records. Each record contains indications for drug and disease. I have been able to calculate the Outcome Rate in the population given a particular drug....
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Why under constant sample size I can get different guarantees on Type I and Type 2 errors, and MDE

I have been tricked by this basic question on hypothesis testing. Imagine you are setting up an experiment. The sample size is a function of the minimum detectable effect and the guarantees that you ...
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Normality test and parametric vs non parametric tests

I'm pretty new in statistical testing and I'd like some help in what I'm doing. I have two groups of scores from 0-100. Group A has 10 values and group B has 70 values. Initially I'm testing normality ...
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28 views

Chi-squared test simulation significance threshold

I have asked question on CV here so this is a follow up. I believe this time I have the chi-squared test correct. In this example I'm simulating o (observed ...
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Evaluate the relationship, if any, between the ordering of variables in a correlation matrix and the magnitude of the correlations

Given a correlation matrix, I would like to evaluate if nearby (in the row/column ordering) variables are differently correlated than non-proximate variables. That is, are the correlations a function ...
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Chi-squared test on small number of groups and large observations

I'm comparing two data sets (3 groups) with relative large number of observations and I'm getting p-value of 0. (0 < 0.05, meaning rejecting H0, that the samples are equal, when in fact there is ...
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How to test the difference in mean between a group and a sub-sample of the group?

A year ago some of my colleagues made a rapport for a client in which they were to report the mean of approximately 100 students examination grades. Here a year after the client has found the ...
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How do I determine significant differences between patient data normalised per individual to 100% (therefore having no SD) and the response decrease?

Patients have very different levels of hormones etc naturally so when measuring the effect of a drug designed to decrease this hormone we normalise each patients original score to 100 (%). Then we can ...
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What among location, scale and shape is Kolmogorov–Smirnov test statistic sensitive to and why?

I understand that the Kolmogorov–Smirnov test statistic for a given cumulative distribution function $F(x)$ is $D_n = \sup_x |F_n(x) - F(x)|$. However, if I have to rank its sensitivity to location, ...
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23 views

Choice of statistical test

So, I have a study where I have collected gender, age and brand use (either user or non user). I am trying to determine what statistical test to use to determine if a particular brand has greater or ...
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P1 vs P2 in R's power.prop.test function

I'm running a two-sided test for proportions and I want to calculate the sample size necessary to see a 25% difference in either direction from 10%, so I run: ...
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How to “normalize” standard deviations?

I'm a computer science guy who's recently moved into Performance Engineering. As part of this job, I now find myself needing to analyze results of tests (duh). However, my lack of statistical ...
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113 views

Significance vs. goodness-of-fit in regression

Assume that I am interested in analyzing the following linear regression model: $$ Y = \beta_0 +\beta_1 x_1 +\beta_2 x_2+e $$ Please explain the difference between testing the p-value for each ...
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15 views

Comparing two time series' behavior over time

I am looking to get a better understanding of the steps one would undertake to perform a proper backtest or statistical validation/testing of the below theory. What in your opinion would those steps ...
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Statistical test for comparing two frequencies with R

i have this situation. A set of 5000 objects, 4950 blue and 50 green. From this set two people (person A and person B) fish separately 100 objects each and i would like to know if one of the two ...
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Can I assess the significance of a linear trend by correlating the trend to the data?

I have an approx. 50 year time-series of the maximum wind speed for a given location in summer (Dec-Jan-Feb). The time-series shows a negative linear trend (weakening of the winds over time), however ...
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Statistical significance from an iterated count

Question in brief: I am attempting to determine whether statistical significance can be measured merely from counts generated from iterating the same procedure, but where the probability of success is ...
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1answer
37 views

How many Backgammon dice rolls to make doubles percentage statistically significant?

I run an online Backgammon game and the most common complaint that I get is that the computer rolls too many doubles (a complaint for every online Backgammon game apparently). I started tracking the ...