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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Repeated measures - sum of biomassproduction

I am student in biology. For my examination I conducted a greenhouse experiment with gras. Actually I am not sure how to develop the correct model and unfortunately I haven't found an answer in the ...
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test interactions for multiple regression with many predictor variables

I have a data set with around 25 predictor variables. If I am planning to build multi-regression model against this data set. What are the general approaches to test the interactions of these ...
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14 views

What does the intercept correspond in the Anova() function in R?

I've been struggling to understand what the intercept sums of squares and p-value correspond to when I run a one-way ANOVA with Type "III" sums of squares using the Anova() function in the car ...
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7 views

mixed design and simple main effect analysis in SPSS

Hope someone can help me. I have a within subject variable (Question, with 11 conditions) and a between subject variable (stimulation, with 3 conditions). I did an ANOVA and I obtained a main effect ...
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6 views

What options do I have to analyze Non-parametric version of two-factor ANOVA with repetition?

Sorry, my previous question was not very clear I deleted it and am trying again. Question: What options do I have for two-factor non-parametric version of ANOVA with repetition? What is the ...
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19 views

Statistical test: Does actual time series data deviate from forecast?

I have made a prediction of future sales based on an ARIMA model. The ARIMA model is based on past data, during which there has been no marketing activity. During the period predicted by ARIMA, I will ...
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53 views

How to best approach ANOVA with multiple response variables that might be correlated and Bonferroni Correction

I need some help verifying a simple analysis. I have completed a simple two factor experiment of more or less equal sample sizes. Let's assume for the case of this question that the sample sizes are ...
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17 views

Do I use ANOVA or MANOVA and why

I have a project for my thesis with both between groups subjects and within groups subjects. The independent variable is the program I am running and the dependent variable consists of 6 different ...
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6 views

Test(s) For Comparing qPCR results / ΔΔCт values

To be clear, I'm talking about real-time polmerase chain reaction (qPCR), not Principle Component Regression. Though from a company selling qPCR reagents, here is a good walk-through of the ...
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22 views

Regarding Nested Anova in R

I would just like to double check if my approach to the following analysis was correct. Based on my design I have two treatments (A and B) with treatment A being comprised of 5 populations and B of 3 ...
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24 views

How to interpret ANOVA output comparing two models

I'm working with the Blackmoor data from the study "Female adolescents with anorexia nervosa and their parents." I've made 4 models based on this: ...
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11 views

which test for means of coded, categorical discussion forum posts?

I'm trying to wrap my head around this problem, how to state it formally for analysis (what kind of study is it) and which test(s) to run: I am comparing the content of 2 discussion forums (the study ...
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31 views

Which Statistical Test?

I am currently appraising an article for my postgrad and wondering if people could help me out. The aim of the study was to investigate one possible parameter influencing running pattern: midsole ...
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Conditions on ratio of $\frac{\sigma_{BIB}^2}{\sigma_{RB}^2}$

I'm attempting to solve a question about the variances of random block design versus balanced incomplete block design. I feel I am close to having an answer, but I'm not quite there yet. Question: ...
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30 views

Appropriate statistical test to measure treatment order and baseline comparison (control groups)

I'm conducting a psychology experiment where I will be looking at whether an activity will have an effect on memory recall, and where this activity may assist in recall before memorisation task and ...
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1answer
77 views

Calculate P value for the correlation coefficient

I would like to understand how people add the P value on a figure for means (Y axis) by age, volume or any other variable (x axis). How did they calculate the P value here? Please check the following ...
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1answer
23 views

Confused Beginner Question: Multiple simultaneous tests and signal pollution

The best way for me to explain the problem might be to just give an instance of our data and the type of test/conclusion I am attempting to draw. Unfortunately as the title suggests, my understanding ...
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22 views

Difference in Chi-square calculated by anova from cph and coxph

Is there a difference between Chi-square (from coxph -> anova) and Wald Chi-square (from cph ...
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19 views

Two-way between groups ANOVA for non-normal data

I'm doing a study on visual selective attention (VSA) and how this is influenced by gender and video gaming. So my dependent variable is VSA (continuous) and my two independent variables are gender ...
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1answer
30 views

Testing if a interval scaled variable A and a nominally scaled variable B are independet when A is not normally distributed

We have a variable A which denotes a percentage between 0 and 1. The variable is not normally distributed but has a very left skewed distribution. About 5% of the observations are zero, most ...
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1answer
41 views

How to test for differences among 3 treatments pre & post, all within subjects?

I want to compare the changes in blood pressure occurring following 2 anesthetic drugs. So in a crossover design, each participant comes for 3 sessions and gets either of placebo, drug A or drug B on ...
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27 views

How to determine which covariates to use

This may seem like a basic question but here goes... I am looking at the effect of brain stimulation on skill acquisition across several timepoints. I have several measures that may be useful as ...
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2answers
30 views

How to model “amount of correlation between two metric items along a third metric item”?

I'm trying to understand the best way for analysis whether the tightness of the correlation between to items correlates with a third variable; a toy example might be the question: "does the ...
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18 views

Interpreting an interaction in the presence of main effects

I'm having a crisis of confidence in my stats and I was wondering if somebody could help me. I ran a 2 x 2 x 2 x 3 repeated measures ANOVA and got: 2 main effects 3 2 x 2 interactions and a 3 way ...
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Three-way Anova with repeated measures

I am investigating the attribution of different types of emotion between two groups. This will in turn help to investigate the level of dehumanisation between them. I am therefore required to ...
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1answer
14 views

Comparing groups within specific conditions

So I have a hypothesis that goes as follows: the relationship between gender of the leader and perceived effectiveness is moderated by company performance. I did some analyses on this and this ...
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9 views

mixed within-between ANOVA. I have a significant interaction but no significant main effect

I am currently trying to interpret the output of my mixed within-between ANOVA. I have 2 groups (experimental and control) and 2 time points (pre and post intervention).The dependent variable is a ...
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1answer
26 views

Why does my repeated measures ANOVA analysis vary when I organize my data differently?

In my study there were 63 types of stimuli (63 levels of the IV) and all types had 8 different examples (8 trials per level of IV) which were all categorized by each participant. Accuracy of ...
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2answers
40 views

Do I struggle with multiple comparisons?

I know that if there is significant difference in means among groups in ANOVA, then one can perfrom post-hoc test ( Tukey HSD or something similiar) to get to know within which groups the difference ...
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9 views

Follow up comparisons for a repeated measures ANOVA while ignoring some factors

So I have a big data frame with my dependent variable stored in RT and my subject number stored in s. I'm interested in doing within-subject ANOVAs on the means of each subject score per unique ...
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1answer
33 views

1-Way ANOVA with single independent/repeated (within/between) factor

I want to perform an ANOVA on data with a single factor with three levels. The difficulty for me is that two of the levels are repeated measures (within subjects) and the third level is independent ...
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1answer
58 views

What is the lme4::lmer equivalent of a three-way repeated measures ANOVA?

My question is based on this response which showed which lme4::lmer model corresponds to a two-way repeated measures ANOVA: ...
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17 views

Diagnostics for the analysis of variance model

I have problem with the diagnostic of the one way analysis of variance model (fitted in R). I've checked all the assumptions of the analysis of variance 1) "For each level of the within-subjects ...
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1answer
46 views

How can I run an analysis of variance with one independent variable and multiple dependent variables?

From my limited statistical knowledge, I could use MANOVA if I had multiple independent variables (x1, x2...xn). What can I do (specifically in R) with one "x" variable and multiple "y" groups? I'm ...
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How to report confidence intervals for an interaction?

I have a significant interaction in a repeated measures ANOVA. Two groups in my data are significantly different from one another. In order to report the overall confidence intervals, when I report ...
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1answer
21 views

post-hoc for non homogeneous data

Which post-hoc test is used for non homogeneous data. I have checked my data set and they are normally distributes. I used Anova with Levene's test and it showed that my data is not homogeneous, and ...
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26 views

1-way and 2-way ANOVA giving wildly different results

I'm hoping someone can help me understand this. I'm using sigmastat 10. My data consists of multiple outcomes (2 continuous and 2 count) belonging to 3 groups (test/sham/naive). If I perform a 1-way ...
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2answers
89 views

data analysis, dissertation of thesis? help please?

I'm having a problem with my dissertation. My research is "level of satisfaction in relation to customer service: comparative study between 2 fast foods my questionnaire consists of 19 questions. ...
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21 views

anova, I'm a newbie - how?

I have 2 groups, C and P. For each group I have 6 conditions. Each of these conditions has a timeseries of data i.e. 2 secs of data, 501 samples (Note,this is averaged across subjects in each group). ...
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39 views

Power/Sample size calculation with R pwr.anova.test

I would like to use pwr.anova.test (R package) to calculate power or sample sizes etc. The function needs several parameters: pwr.anova.test(k = NULL, n = NULL, f = NULL, sig.level = 0.05, power = ...
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1answer
38 views

Curse of dimensionality mimics multicollinearity?

Why does the curse of dimensionality mimic multicollinearity, in the following sense.. Consider the random vector $Y = [y_{1}, \dots, y_{4}]$ where each element is ~ Uniform (0,1). Take 10 samples ...
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1answer
14 views

Testing GLIMMIX assumptions

I am currently doing GLIMMIX models in SAS. I choosed GLIMMIX as my data is count data, generally well described by a Poisson distribution. My question: What assumptions can you test to ensure that ...
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3answers
55 views

ANOVA with outlier group

This is my first question (previously the search function has been enough), so please bear with me. I have a very simple experimental design with one outcome variable and 5 groups. My typical ...
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1answer
113 views

I just don't get the t-test

I know it sounds abysmally ignorant, but here we go. I understand the basic logic behind the t-test: you want to know whether the difference in the mean of two samples is due to chance or not. To ...
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9 views

Two Way ANOVA with Repeated Measures, Greenhouse-Geiser test shows no significant difference although pairwise comparison tables shows a difference?

I have run a statistical test on a batch of data and it has thrown me off course. I have run a two way ANOVA with repeated measures and when running through the output of data from this test firstly ...
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26 views

Two-way Repeated Measures ANOVA with replicated measures

My experiment involves 16 participants with a dependent variable (PP) tested under 2 conditions, across 3 different time-points. At every time-point, each participant is tested twice. My data is ...
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1answer
47 views

Statistical significance test: One way Anova and Kruskal-Wallis test

I was comparing data between two groups and for each group there was six samples. My data are as follows: group 1: 103.56, 103.32, 103.32, 104.27, 103.56, 103.8 group 2: 97.16, 97.16, 96.69, 98.58, ...
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1answer
21 views

does ANOVA have to work on groups with replicates? [duplicate]

I want to test if the means of different groups (tissue types) are different using one-way ANOVA. Most of the groups have replicates but there is one group that only has one sample. Like this: heart, ...
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3answers
115 views

Appropriateness of ANOVA after k-means cluster analysis

The notification after the ANOVA table after K-means analysis indicates that significance levels should not be looked at as the test of equal means, as the cluster solution has been derived based on ...
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1answer
30 views

Sample size for ANOVA

Is there minimum sample size for each group in 1-way ANOVA? if yes, please give a reference(s), If no, why there is not?