ANOVA stands for ANalysis Of VAriance, a statistical model and set of procedures for comparing multiple group means. The independent variables in an ANOVA model are categorical, but an ANOVA table can be used to test continuous variables as well.

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SPSS Repeated measure ANOVA model [on hold]

I am running repeated measure ANOVA with two independent variables: time (3 levels) and task (2 levels). I noticed that SPSS and Minitab give different results, some exploring showed that differences ...
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How to analyze skewed and unskewed data on SPSS?

Study design: I have shown participants a series of photos of themselves vs. other people's bodies (original and manipulated), and asked them to find the original. Their responses were recorded and ...
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Repeated measure ANOVA how to interpret

I am running a repeated measure ANOVA with one 2 level DV (within subject factor) and three 2 level IV (between subject factor). I observe that one of my between subjects variables has a significant ...
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1answer
17 views

How to run repeated-measures ANOVA when data points per subject vary?

I am attempting to run statistics in the following scenario: I have a list of hospital visits by approx. 60 patients to the emergency room. Each patient gets an EKG done of their heart, and I have ...
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9 views

Contrasts / Post Hoc Tests for three way repeated measures ANOVA

I have three factors A B and C with 2, 2 and 3 levels. A and C have significant main effects, B is not significant, interaction A*C is significant, the others are not. Now I want to know how to ...
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8 views

Help with Data Analysis - using Minitab [on hold]

I am new to DOE. I have performed manufacturing conditions optimization experiment (turning). I have 4 controllable input parameters and 2 response variables From my experimental data I have 4 ...
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26 views

Can I use PERMANOVA here? [on hold]

The PERMANOVA algorithm is described as follows: Analyses univariate or multivariate data in response to factors, groups or treatments in an experimental design. PERMANOVA can be used as a better ...
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10 views

Non-parametric alternative to a mixed anova?

My data fails assumptions of variance - (norm dist is good though) - and I was wondering if anyone had a suggestion for an alternative to a mixed anova? Three repeated measures (Test 1, Test 2, Test ...
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21 views

Comparing means of different training programs in R

I have a data set with performance and training data that looks something like (this is not the exact data, but gives a general idea): ...
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15 views

Two-way ANOVA - discrepancy between main result and model parameters

I am running a two-way ANOVA examining the influence of both school and gender on Likert scale answers. The Type III SS results show school significant (p=0,001), but gender or gender*school not ...
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32 views

Data Analysis in psychiatric

A 30 item questionnaire in accept or decline form consisting of commonly encountered dysfunctional beliefs about psychiatric issues was administered to medical students. The questionnaire is in the ...
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1answer
23 views

R lsmeans in a model with two residuals (split-plot) [on hold]

Let's assume the model: lm(VAR ~ A * B + (A : R), data) which produces this ANOVA: ...
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31 views

Power Calculations in R for ANOVA's

I need to use R code to calculate the power of a Nested ANOVA. I want to detect a 3% difference between two consecutive tests between a stage in a process. The tests are identical and material has ...
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21 views

Power calculations in R [duplicate]

I need to use R code to calculate the power of a Nested ANOVA. I want to detect a 3% difference between two consecutive tests between a stage in a process. The tests are identical and material has ...
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8 views

Statistically verifying distribution of users within an A/B Test

Hoping you can help me determine the best way to statistically verify that an A/B test was set up in an unbiased way. The A/B test was set up to split users on my website 50/50 into a test/control ...
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14 views

Determinin fixed effects' contribution to variation with ANOVA results

I have performed an ANOVA (Linear model in SAS EG) to determine the role of country, farm, sex and year-season on performances of pigs and ran pair-wise bonferroni tests on country, farm and sex (LSM ...
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1answer
37 views

Back transformation of log10 transformed data in SPSS

I have transformed my quantitative variable by using the log10 function in order to run some parametric tests (ANOVA) but when I want to make pairwise comparisons ...
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1answer
48 views

Standardization before applying ANOVA?

I have a matrix where the rows are the data points (samples) and the columns are the features. It is a multiclass (4 classes) problem. On this data I want to apply machine learning classifiers. But ...
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28 views

Standard Error of estimate of variance

I am not understanding how is the standard error of estimates of two-factor factorial random effect model calculated ? For example , In the book Design and Analysis of Experiments , by Douglas C. ...
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Unequal sample sizes ANOVA in R

I usually use ezANOVA as my data sets are typically equal with regard sample sizes. However I have a sample size that is not equal. Here is an example of the data: ...
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2answers
41 views

Can you perform an ANOVA on r-values (correlation values)?

I am doing neuroimaging research yielding what is essentially a correlational analysis wherein my output is a brain's-worth of r-values (so like 15000 voxels worth of r-values). In this particular ...
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1answer
18 views

How to address unintended confounding in an experiment

I am conducting a study looking at the effects of 3 different footwear conditions on energy expenditure during running. This will be a repeated measures study. I want to control for the effects of ...
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21 views

Effect size for contrasts in hierarchical Bayesian “ANOVA”

Kruschke (2014) shows in his book how to compute posterior distributions of effect sizes (standardized mean difference) for the Bayesian analogues of frequentist independent-samples t-tests, and ...
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30 views

Comparing more than two populations

I have a dataset of around 20 financial advisors and their customers. The customers have been divided into groups based on type of investment, as well as the size of their investment and whether the ...
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5answers
85 views

Why isn't independence checked standard in ANOVA?

The standard procedure for a one-way analysis of variance seems to be: fractile-diagram (or Q-Q plot) for checking normality Bartlet's test for heteroscedasticity But as standard I have never ...
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Using R to calculate between- by within-subj ANOVA interaction contrasts using car or lme [migrated]

Psychology student here. As part of my thesis I have some data from an experiment with two between-subjects IVs, classification and ...
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1answer
24 views

two-way anova when lacking one observation

I want to perform a two-way ANOVA in a data frame that lacks one observation. I have values for each (month,year) pair, and I am performing a two-way ANOVA to check if moving seasonality exists. ...
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1answer
21 views

Kruskall-Wallis test. How many degrees of freedom to report?

I have run a kruskall-wallis test to see if there is a significant difference in the amount of fish at each site. There are three sites (Site1, Site2 and Site3), with 80 observations of fish in each ...
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1answer
44 views

Can I use binary covariate in anova?

I am performaning an anova and have resilience and anxiety scores that want to use as covariates. These are coded into high and low. If I imput them as covariates I obtain significant results. ...
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Should two way anova with unequal samples use weighted or unweighted means?

My data were collected in a 4x2 factorial design with 4 sample areas and either high or low rainfall. I'm looking to carry out a two-way ANOVA but the sample sizes are not even. Should I use ...
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1answer
33 views

Difference between multi-factor ANOVA and Cox proportional hazard model?

I am wondering what is the difference between multi-factor ANOVA and Cox proportional hazard model? As I understood both of them test the significance of some independent factors on a dependent ...
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5answers
32 views

No statistical significance between group means determined by ANOVA

After performing a one-way analysis of variance (ANOVA) and determining that there is no statistical significances between group means is it permissible to then aggregate the means to obtain a “grand” ...
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39 views

What does the P value in restricted cubic spline plot mean? [duplicate]

What does the P value in the following example mean? ...
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How to test whether correlate personality ratings with behavioural observations

I'm running a study to test whether personality (Big Five) predicts problem-solving in children ($N=200$), and was wondering whether anyone could help with the best approach for analysis. I've ...
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15 views

Statistical Test similar to ANOVA for multiple factors with continuous values

I am stumped trying to determine the best method to analyze my data. I have numerical ratings provided by users to describe different objects. Additionally, there are five factors that describe these ...
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28 views

Logistic Regression as Data Transform?

I'm analyzing medical research data with a small sample size that is not easy to replicate because the data were collected on an invasive procedure. The outcome variable is binary. There are two ...
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1answer
27 views

ANOVA Independence Assumption

I'm trying to get a better understanding of how the independence assumption can be violated in ANOVA. To this end, I've come up with an example using one factor with 3 levels: Say we're doing an ...
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40 views

What type of Anova to use and how (in R)?

I tried to find differences between delta G values in amino acids between 9 species. Here is a link to the table that I read in. (The header lists the species): ...
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34 views

repeated measures design of Analysis of variance (ANOVA) with mean not statistically significant and Standard deviation significant

The study area was sampled using a tessellation-based stratified sampling scheme. The area was divided into 50-m × 50-m squares, a point was randomly selected in each square. For each point, a ...
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1answer
20 views

Comparing Species diversity of 32 plots between years

I need to know what type of test to use to compare species diversity between 2 years. I have been analyzing a species survey data set collected in 2012 and 2014. The data include stem count ...
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5 views

ANOVA for differentiating between two groups with one much bigger than the other

I have a dataset with about 5-10% of data belonging to some distribution $A$, and the rest belongs to another distribution, $B$. The distributions are different, $A$ appears to be Gaussian and $B$ is ...
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21 views

Repeated Measures ANOVA SPSS

I have the following predictors: - 2 within subject factors - 4 between subject facors Theoretically, I'm mostly interested in the main and interaction effect between the 2 within subject factors as ...
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7 views

Interpreting Tukey test for significant differences

Hi I have 38 categories and I have their means. I want to see if the differences in means are significantly different. I ran an anova and the p-value is <2e-16. Then I wanted to investigate ...
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rANOVA - three trials for one group in two conditions

We studied postural performance under the influence of exercises of moderate and hard intensity with and without restriction of body mobility. Therefore, there was three trials (no exercise, moderate ...
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Can I still use RCBD with incomplete levels in one of the treatment

I'm trying to see the differences among sites based on distance from pollution source and months of sampling of my oxygen flux measurement. I have 3 almost identical pollution source. So I took 4 ...
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How is it computationally possible to calculate ANOVA of microarrays with interactions of 4000 genes and 7 times

M. Kerr and G. Churchill use ANOVA to separate changes in gene expressions from effects due to the used arrays or dye using the interaction terms time*gene As they are dealing with yeast which has ...
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16 views

Correct test to test effects of time and treatment

I have a dataset consisting of 3 treatment levels (A, B and C) and a response variable (plant height). Each treatment has 10 plants. Each plant is measured twice, once at the beginning and end. I ...
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24 views

Which stats test to use

I am a UK Clinical Psychology Trainee carrying out a small (5000 words) service improvement project based on where I am on placement. The title of the project is: “Quantifying and comparing uptake of ...
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3answers
64 views

Estimates of the variance of the variance component of a mixed effects model

Say $y=X\beta+ Zu +\epsilon$ is our mixed effects model where $u=(u_1,..,u_r)$ and $u_{j} \stackrel{i.i.d.}{\sim} N(0, \sigma^2_{a})$ for $j=1,...,r$ and $\epsilon=(\epsilon_1,...,\epsilon_n)$ are ...