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
Detecting a (statistically) significant change in time series trend
Suppose I have two time series (Series1 and Series2) which are identical from timePeriod -200 to timePeriod 0. Say that in timePeriod 0 they are both equal to 100. Series1is equal to 200 at timePeriod ...
-3
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0answers
17 views
Please show me that with which formula, I can calculate pooled variance for unequal population variance?
I know it not legal and valid for faq but I cannot put a photo here because of reputation and not logged in here. Sorry. This is last question. After this, I never put link here. Sorry.
My question ...
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1answer
38 views
What is the sample standard error formula?
What is the sample standard error formula?
I know only $s$ but I guess this is not it.
I am confused about its formula. Please help me. Thank you.
1
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0answers
27 views
New method for meta-analysis to determine agreement between multiple sources
I'm writing a paper on a method to determine the statistical significance of whether a sample of sources are in mutual agreement on specific premises. This is done by counting the number of sources in ...
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2answers
17 views
bias of peeking at AB test data and adjusting minimum detectable effect
Let's say we're running an A/B test on my website comparing blue button clicks (baseline) to green button clicks.
I use http://www.evanmiller.org/ab-testing/sample-size.html to calculate my required ...
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0answers
8 views
Merging and analysis of data from replicate time course experiments
Could you please provide advice on the merging and analysis of data from the replicate time course experiments described below?:
Relative amounts of a protein expressed by aliquots of cells (from a ...
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1answer
22 views
Are suvey responses of ranking significantly different from mean ranking?
I'm a stats dummy, so please use small words. (-:
This might not be a valid test, so I'm sure you'll let me know if that's the case.
I have some survey responses in which the responses are rankings ...
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0answers
32 views
what does this +/- of “average” mean?
I have a set of data points and I was told that for it to be valid, every data point should be within +/- say 5% of the average of the entire dataset.
I have no problem of checking each data point ...
5
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1answer
36 views
Logistic model, what is more important: Anova Chi-sq test or significance of coefficients
I have a logistic model with 8 variables. I ran a chi square test in R (anova(glm.model,test='Chisq')) and 2 of the variables turn out to be predictive when ordered at the top of the test and not so ...
4
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0answers
36 views
Testing two trendlines for statistical significance
Background
I am comparing data on how ATPase activity from flight and leg muscle from locusts reacts to different concentrations of calcium. I plotted a scatter graph of each data set on the same ...
1
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1answer
29 views
Test on the properties of two betas?
I have a set of observation. When I do an OLS I get a beta. After I remove some values I also get a beta. Now I want to test if the properties of two betas are the same? Pls give me a hint how to do ...
3
votes
1answer
62 views
Interpretation of a Durbin-Watson test?
I have calculated a Durbin-Watson test and got as far as
$$\eqalign{
d&=2.207551844, \\
dL&= 1.6164, \\
dU&= 1.7896.
}$$
I want to test
$$H_0 \gt 0,\ H_1 \le 0.$$
However, I do not ...
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0answers
22 views
Assessing Significance in Neural Networks
I'm trying to determine statistical significance of inputs on the dependent variable using neural networks. I'm trying to test the null hypothesis that the partial derivatives are equal to zero. I ...
1
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0answers
31 views
Shapiro test on replicated values
I have a distribution of frequencies (1000 data points) expressed as %. The list of data looks like this:
3.10%
1.80%
1.70%
1.70%
1.60%
1.60%
1.50%
I would like ...
1
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2answers
41 views
How to compare Likert scale items before and after an intervention?
I have been struggling with this question all day, reading everything I could find, but still do not have a clear answer.
A part of my research was that: 30 students tried a new educational ...
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0answers
17 views
marginal effect clogit not significant
I developed a coniditional logit model on STATA, the model is good and the variables are highly significant
Then I do mfx predicted (PU0) to determine the marginal effects of variables (dy / dx). the ...
1
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0answers
33 views
How do I analyse a two-alternative forced choice test?
I have recently as part of my bachelor project at my university conducted a two-alternative forced choice test. I have looked at ways to say something with significance about which images (the test ...
1
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1answer
17 views
Insignificant block effect in two-way block design
I used a two-way ANOVA to analyze data collected in a randomized complete block design:
Y~Treatment+Block, where blocks represented spatial units
Whereas Treatment had a significant effect on Y, ...
1
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1answer
52 views
Ordinary Least Squares method: why are my regression results insignificant?
I have a problem in my thesis results of OLS regression being insignificant.
I have 3 sectors and each sector has 130 observations.
Is this sample size is sufficient or not ?
Can anyone suggest ...
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0answers
47 views
Measuring the presence of a correlation
Given a frequency data set (collected from 10 users by letting them watch certain videos and asking some questions about the videos) how do I determine any correlation between two variables (...
0
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1answer
43 views
Statistical test over binary data
Given certain products (ProductA, ProductB, ProductC, etc..) users are asked to rank them according to their preference (whether they like, somewhat like, or not like, the product).
Thereafter I ...
4
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0answers
38 views
How to test whether mean and variance is the same in two small samples?
I would like to test two relatively small samples against the null hypothesis that both their means and variances are the same. The alternative would be that they in fact differ. I saw a post on this ...
1
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0answers
26 views
How to extend multiple regression hypothesis tests to multivariate?
I have a basic multivariate regression model $\mathbf{Y}$ = $\mathbf{XB}$ + error
$\begin{bmatrix}y_{1i} \\ y_{2i} \\ \vdots \\ y_{ki} \end{bmatrix}$ =
$\begin{bmatrix} X_{11} & ... & X_{1p} ...
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0answers
28 views
Statistical Significance test for difference in FScore
For a classification task, I have developed two methods and FScore(harmonic mean of precision and recall) of both the classes serves as the performance criteria. How can I check whether the difference ...
1
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1answer
60 views
Can I use a regression model with ANOVA significance greater than 0.05?
I have a multiple regression using SPSS. The significance of my model in the ANOVA table is p=0.174 which is >0.05. what does this mean for my model? Can I still use it and proceed in the ...
4
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1answer
39 views
How to rank order performance of four systems using aggregates of pairwise assessments of system performance?
I am currently designing an experiment to evaluate 4 iterations of a system. As it is rather difficult for a human to judge the output of the system by assigning it a score or several scores, I plan ...
2
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2answers
114 views
Stats: Relationship between Alpha and Beta
My question has to do with the relationship between alpha and beta and their definitions in statistics.
alpha = type I error rate = significance level under consideration that the NULL hypothesis is ...
2
votes
1answer
34 views
Statistical tool(s) to correlate perceptions with Likert-type scales
In relation to perceptions of teachers, I want to measure:
perception of helpfulness
required level of helpfulness for the respondent to be satisfied, and
how important helpfulness is (as an aspect ...
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1answer
35 views
Simple Mixed Model with 1 Fixed and 1 Random Effect
I have various datasets I need to analyse regarding soil properties, all in the same fashion, with one fixed effect (which is a position along a transect, indicating different land uses). Now my main ...
1
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0answers
16 views
Significance testing for a group of samples
For instance, I have a bar chart - in which I have 4 samples/bars. for these 4 bars, I want to check statistical significance for all combinations.
How can I do it? Can unpaired t-test be used - to ...
1
vote
2answers
64 views
Correlation not significant because there is not enough variance?
I have a question about correlations again.
I have a dichotomous variable that I want to correlate with the another one (metric) by using the point-biserial correlation coefficient. I get a ...
3
votes
2answers
118 views
How to compare percentages for two categories from one sample?
I want to compare two percentages on a single categorical variable from one sample.
For example, in my data set, a variable can take on two values (i.e. A and B). Of 586 instances, 87.4% is in ...
3
votes
1answer
21 views
Statistical significance and winner of multivalent test
This should be a fairly straight forward, but I can't seem to figure out the answer. I'm doing some A/B(C/D/E...) testing on a website and measuring impressions and clicks. What method should I be ...
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2answers
70 views
Pearson correlation is not significant although effect is .30 What could be the reason?
I have a correlation between two variables of 0.30, hence a medium effect. but it is not statistically significant and I want to report the reasons for that. looking at the test statistic I see that ...
4
votes
3answers
121 views
Problem with p-values from A/B testing
I'm pretty confused right now and the more I look at it, the more confused I get. Overthinking!
I'm doing some A/B tests for my website. I'm using the significance calculator that's in this article:
...
2
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0answers
16 views
How to test significance of pre-post difference scores on 8 measures (1 group)
I have a set of pre and post treatment scores on 8 measures. I'd like to test which of these show significant improvement after treatment. If I use within-subjects t tests it will mean carrying out 8 ...
2
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2answers
269 views
1
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0answers
46 views
Two-way anova with interaction term: what is the point of a post-hoc test?
I have a statistics interpretation question. I've recently performed a two-way anova to identify an interaction term between my categorical independent variables (genotype + temperature) that ...
2
votes
1answer
70 views
How to compare two datasets using metrics drawn from unknown distributions and with small sample sizes?
I have two datasets consisting of metrics from several experiments. Dataset 1 is the collection of results of experiments E performed by user A on product A, repeated N times. Dataset 2 is the ...
1
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1answer
116 views
Looking for help with interpreting my OLS models
I have been busy building an explainatory regression model for a companies' social behavior. In the table below you find the variables, ordered by theme. The ...
3
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0answers
164 views
Ratios of means - statistical comparison test using Fieller's theorem?
I would really appreciate any suggestions with the following data analysis issue. Please read till the end as the problem at first may appear trivial, but after much researching, I assure you it is ...
1
vote
0answers
24 views
Test regression parameter against a constant in SPSS
This is a pretty basic question, but I can't find an answer by searching for different statements of the same problem.
Is there a straightforward way to test if a regression parameter is different ...
0
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0answers
33 views
Correcting Classical Linear Regression Model (CLRM) violation
How would you correct for violated error term assumption of CLRM in stata. If our hypothesis is correct, our assumption of error term is violated. I am trying to correct this on stata but don't know ...
3
votes
1answer
32 views
How to prove the number of distinct distributions in a group of distributions?
Let's say we had 5 distributions: A,B,C,D,E.
An ANOVA test would tell us whether or not all of the means are equal, and thus a low p-value would mean at least one of the means is unlikely to be ...
1
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0answers
32 views
Hidden Markov model & statistical significance
I am using HMM to explore the language development of one individual with six variables as input, which are trained into three sequences.
In the first state, the covariance of variable A and B is ...
0
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1answer
72 views
Interpretation of Spearman correlation for small sample
I am currently being confused by different opinions regarding the spearman correlation interpretation. Some says, $\rho<0.2$ can be ignored as small/weak relationship, some says $\rho<0.1$, for ...
0
votes
0answers
54 views
Statistical test for multiple comparison with dependent observations (MATLAB)
I want to use matlab to perform a statistical test to find if there's a significantly higher mean return in any of n different sample populations. However, I can only find post hoc (although they can ...
2
votes
1answer
81 views
Test for significance of correlation matrix
If one wishes to test if the correlations in a correlation matrix are statistically significant as a whole group, one can perform a likelihood ratio test of the hypothesis that the correlation matrix ...
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0answers
29 views
How to test if two populations are different with the x axis a time variable
I have two populations: Class A and Class B. Both populations have two variables: ...
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0answers
30 views
What kind of statistical analysis to use for a homework paper? Anova?
I am writing a paper where I have to pretend to have conducted an experiment. Each of the experimental groups and control has different people.
There are 8 experimental groups and 1 control.
1a 1b ...
