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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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How much better does one distribution approximate a value than a second distribution?

I have two samples (see graphic below), and I would like to know with what degree of certainty I can claim that one of them deviates less from 1 than the other. I am aware of this question but I find ...
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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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Can I report both Spearman and One way ANOVA tests for the same variables?

I have one continuous variable (number of actions on a platform) and a ranked variable (education: values from 0 to 3). My research question is "Do people with more education perform more actions on ...
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What statistical analysis?

I have 4 groups in which C is a cotrol group that had no surgeries but sampled the same as other groups. A, B and C had different rumenotomy techniques of surgery. Each group had males and 3 female ...
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1answer
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How to calculate all treatment effects in SAS with ANOVA?

In a hypothetical experiment, rats are given four different treatments and the increase in their liver fat is measured. I am being tasked with computing the overall mean and the treatment effects. ...
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1answer
29 views

How to run a Two Way ANOVA in SAS? [on hold]

I have a data set that looks like below. I have to find if the scores are different across the four days. I understand I need to run a Two Way ANOVA for this test. I'm quite new to SAS if anyone could ...
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R: How do i employ Fisher LSD following Mixed Factor ANOVA?

I'm very new to R and a novice in statistics. I've been given a task to run a Fishers LSD posthoc on the output of a Mixed ANOVA. Ive tried the LSD.test in the agricolae package and it works on ...
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Understanding ANOVA as regression / type III SS in R

I'm confused about how type III SS are calculated for a "main effect". According to what I have read, Type III SS is calculated by evaluating the change in the SSE by removing only the variable in ...
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Non-orthogonal experimental design and model selection

I am working on designing some chemical experiments, with the goal (for now) to optimize reaction yield. I intend to use principal component scores in order to investigate solvents, Lewis acids etc. ...
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2 way anova failing anova assumptions -R

Using 2 way Anova I have been trying to find pairwise groups having mean differences statistically significant (p-val <0.05) from a dataset of 2932 obs. and 3 variables (2 categorical independent ...
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What's special about orthogonal contrasts?

In my Design and Analysis class we talked about orthogonal contrasts when it comes to running an ANOVA for one factor of several levels. I understand what it means for two contrasts to be orthogonal. ...
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1answer
45 views

Confusing main effect in mixed design ANOVA

I am conducting a mixed design ANOVA test using ezANOVA. I ran two different tests as follows: Test1: within subject variable w, between subject variables age and x1. Test2: within subject variable ...
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R: contrasts and Sum of Squares for lm or clm models

I had a hard time the last days, trying to understand contrasts and types of Sumsquares in R. I hope someone here can help me with this: I fitted a clm model (package ordinal). The outcome is a ...
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T-tests vs multiple comparison tests vs bonferroni in ANOVA?

I'm taking a course in experiment design and I'm having a hard time grasping the comparative usefulness of t-tests, multiple compariseon tests and bonferroni methods. I understand that in using ...
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Why do we discuss ANOVA and completely randomized design together?

It is common that textbook discusses completely randomized design and ANOVA together. However, it is not clear to me at all how does CRD "translate" to ANOVA. For example, does CRD imply that the ...
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WIth Latin square design, is this situation valid?

I have no background in statistics so I would like to know whether I get it right: Q: suppose I evaluate 3 Teaching methods in 3 schools and in 3 classes (First, Second and Third). I know that the ...
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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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Power Analysis for a mixed two-way ANOVA with unqual sample sizes

I have a simple study design with a between-subject factor drug (real drug vs. placebo) and a within-subject factor time (three visits= repeated measures). I want to run a mixed two-way ANOVA and my ...
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Which statistical test do I use to compare two mean differences (i.e. x1-x2 compared to x3-x4)?

I'm running a 3-way ANOVA and wanting to know if there is a test to compare the differences between 2 sets of means. I am looking at the effects of social distance (face-to-face vs online), ...
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Multivariate Normality ANOVA test

ANOVA requires multivariate normality as a key assumption. I understand that this assumption can be tested in MANOVA using the Mardia test, Royston test, and Henze-Zirkler test. This can be ...
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1answer
34 views

Mixed desgin ANOVA or LMM?

I am hitting a wall and would appreciate some help. Here is my data (raw data, before computing the means): ...
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1answer
32 views

One way ANOVA or one way repeated measures ANOVA?

If I measure students' output performances on the same activity with different time intervals, i.e. 1 hour, 40 minutes and 20 minutes and want to know if there is a significant difference between ...
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How repeated measures ANOVA is affected by unequal number of observations in each of the conditions?

I have a repeated measures design with 3 conditions. In condition A there are 150 observations for each participant, in condition B I have 20 observations for each participant and in C I have 200 ...
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Simple repeated measures ANOVA in R

I am struggling a bit in the implementation and interpretation of repeated-measures ANOVA in R. Lots of tutorials are available, but most of the time they deal with rather complicated schemes, thus ...
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Confidence Intervals in ANOVA testing

I have read other posts before raising this question. I understood the mechanics behind Anova but I have not fully grasped its essence in logical terms. What I mean is that if I calculate the mean ...
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1answer
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How can I test whether an individual treatment mean significant or not?

Suppose by complete randomization design, I reach into a decision that there is at least difference between two treatment means. That is, my hypothesis is $$H_o:\mu_1=\mu_2=\mu_3=\mu_4=\mu_5$$ $$...
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T-test with nested data

I want to test gender differences in an outcome variable called the willingness to pay. My data consists of records with following three fields: ...
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How do I find an appropriate test statistic for the derivative of a quadratic regression curve?

Suppose I've managed to fit a quadratic regression curve $Y=\beta_0+\beta_1X+\beta_2X^2$ to a dataset. Given some $X=x$, I'm looking for an appropriate test statistic to check if $x$ is an extreme ...
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G*Power 3.1: Computing Numerator df for factorial ANOVA for a priori sample size computation

I have looked everywhere and have not found an answer to my specific design question related to computing the sample size necessary for (specifically) a 2 X 2 X 2 ANOVA. Specifically, using G*Power ...
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Two way ANOVA and post hoc test

I performed a two way ANOVA over a test set. My two nominal variables are treatment and clone. My outcome variable is area. ...
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Is two-factor factorial design most appropriate in this situation?

Suppose there are two factors, A and B. There are 7 levels for factor A and 4 levels of ...
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Mixed ANOVA vs Ordinal logistic mixed model?

I have two different groups, Treatment A vs Treatment B, with measurements for each individual in four different time points. That is a 2 x 4 design. The dependent variable is a discrete scale from 1 ...
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ANOVA and tukey test on categorical variables

I have a data frame like the one below, I want to apply an anova test and tukey post hoc test analysis. ...
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mixed repeated measures ANOVA bayesian analysis using R

I'm quite new to R so that's probably a dumb question. I would like to analyse some data I have using R and the BayesFactor package. My subjects performed 3 behavioural tasks (so the observations for ...
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Post-hoc analysis on data, if three-way ANOVA is showing interaction

I have a data set with three independent variables. After applying three way ANOVA, I see significant three-way as well as two-way interactions. Will it still be acceptable if I apply some post-hoc ...
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Help picking a test for time-series data

I am new to stats and looking for help figuring what is the best test to compare two groups across two time periods. I am working with vegetation abundance data at two locations in two different years....
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Comparison of treatment differences in fully factorial design

I have a dataset from a fully factorial experiment aimed at looking at mortality rates in fish depending on chemical additions. There are manipulations of Buffers (2 types), Nutrients (Ca and Mg) ...
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1answer
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Correction needed for an non-parametric Anova?

I'm trying to analyze the behavioral data of my research experiment and I'm a bit lost... o_O Briefly, subjects undergo 4 different conditions (of increasing complexity 1<2<3<4). At the end ...
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4x2 within-subjects ANOVA power analysis to detect sample size

I am planning a research experiment with a 4x2 within-subjects design, and am currently trying to determine an appropriate sample size for my project (in order to achieve desired power with an effect ...
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Confused about DOE and repeatability

I'm trying to design an experiment. I want to vary Pressure and temperature at two levels (high and low) and measure the effect on quality and flowrate. I'm new to DOE and from my research I need to ...
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1answer
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ANOVA with two factor within subjects design

So i'm currently frustrating about this method of doing a two-factor repeated measures within subject anova (AxBxS-Design). As there is no straight forward way of using a simple scipy call for my ...
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1answer
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Repeated measures factorial assessed using planned contrasts

I have dependent data that can be arrayed as a factorial. I understand that although factorials can be assessed through ANOVA, it is not necessary or always desirable to do so. A second option is 1-...
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How to interpret a multi-interaction ANOVA table using only the sum of squares and mean square columns?

I read in a paper that for an ANOVA table, it is sufficient to only look at the sum of squares and mean square columns. The paper contained an ANOVA table that tested 4 factors up to a 4-way ...
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comparing logit mdeols with different number of observations

I used the following code to compare two logit models (Logit3.4 is the same as Logit3.3 plus an additional variable): ...
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ANOVA or test to distinguish treatment groups [closed]

I have two lots of questions which should be pretty straight forward to solve with an ANOVA or as studies previously used Wilcoxon-Mann Whitney matched pairs. However I'm not quite sure what to tell R....
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1answer
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Which statistical test is appropriate if we can not measure normality

Say I have two devices that purifies milk, device A and device B. I assume Device B is better and it produces milk that is 5% better than A. If I want to test this assumption, I take 8 sample from the ...
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Dummy coding versus contrasts: which compares treatment with control?

I have a data set where I want to compare different treatments with a certain baseline. So I basically have a linear model (ANOVA) like this: outcome = b_0 + sum_i(b_i * x_i) with b_i the fitted ...
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2-way ANOVA in Python statsmodels yields different Sum of Squares than SPSS

I am learning to use Python for my statistical analyses, and while figuring out how to perform a 2-way ANOVA with statsmodels I found that my Python code yielded slightly aberrant values. Comparing ...
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Is it legitimate to design a one-way ANOVA with following post hoc test in mind?

Is it legitimate to design an experiment where I conduct a one-way ANOVA and test for group differences with a post-hoc test? I read on researchgate, that it's bad practice to do so and post-hoc ...