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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Big data database + software for advanced statistical analysis?

I need to run some statistical hypothesis testing, Anova, student's, least square fit, median, data mining, clustering... on a very large quantity of distributed data. (>100TB, Maybe columnar or ...
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34 views

Setting up a aov model in R for a variant of a 2-way nested ANOVA

I have a rather complex experiment i need to analyse The experiment was an infection trial, where the effect of two different infection methods ("inoculation" and "in-contact infection") were ...
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13 views

Help finding rest of the ANOVA table values

I'd like to add a table to this question as it would be easier to show my problem. However, it looks like I can't? I have a regression, residual, and total row. For degrees of freedom I'm given the ...
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19 views

One-way ANOVA: Concluding one true differences without any post-hoc tests?

Let's say that I run a one-way ANOVA with 3+ levels and that it comes out significant. Can I then, from this result alone, conclude that at least the two sample means that differs the most in my data ...
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15 views

Can I compare three averages if no independent variable?

I am not used to this type of data, and am not experienced with statistics so am really getting hung up. This is an undergraduate research project. I have done a total fecal collection on 12 horses. ...
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18 views

How can I interpret a significant one-way repeated measures ANOVA with non-significant pairwise, bonferroni adjusted, comparisons?

I have a dataset with one factor consisting of four levels. I've run a one-way repeated measures ANOVA on the data, which came out significant. However, for the follow-up pairwise, bonferroni ...
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11 views

ANOVA: testing assumption of normality for many groups with few samples per group

Assume the following situation: we have a large number (e.g. 20) with small group sized (e.g. n = 3). I noticed that if I generate values from the uniform distribution, the residuals will look ...
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4 views

Multiway anova doubts

I am new to statistical inference. I have read about one-way/multi-way anova and also between subjects and within subjects design. I would like to conduct a subjective quality test and analyze the ...
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11 views

One way ANOVA or repeated measures?

Does anyone know which type of ANOVA is appropriate to test the hypothesis: 'There is no difference in flexibility (measured in cm) due to type of prior warm-up'? There are 6 different warm-up types. ...
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7 views

The F ratio increases as the variability between means decreases relative to the variability within groups? [on hold]

True or False (unable to locate answer)Trying to determine the F ratio within groups.
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7 views

Difference between measured factor, manipulated factor, covariates.

I am trying to understand this paragraph, and it would be great to have some extra clarity on what is meant? I'm trying to assess whether i can use this formula for collecting data for a ...
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25 views

SPSS ANOVA or MANOVA or huh?

Me again asking the silly questions - this might belong here as I've been told it may belong in a software section somewhere..? Which I have still been unable to find. Here is a screenshot of my ...
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16 views

Significant ANOVA, Insignificant Post-Hoc [duplicate]

This seems to be a popular question, but here it goes. I have a four group categorical set that I am testing on a scale dependent variable. Before testing, it was assumed that the the first group ...
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9 views

TOMS708, How can FPSER ever return a non-trivial answer?

Following from Calculating the "critical value" for F test. I'm looking at the classic TOMS708 Fortran. Initially, I'm wondering how FPSER can ever get called. ...
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20 views

What statistical test? [closed]

I am writing my research proposal and I wondered if anyone could help me decide what tests to perform? I am studying weight change for six weeks post trauma? I also hope to look at gender, age, ...
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25 views

Testing hypothesis when each data instance is a vector

The experiment involved studying population body velocity changes during a marathon . Velocity of each person in control group and experiment group were measured at multiple instances during marathon. ...
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14 views

Analysis of insane factorial designs

I'm seriously thinking of doing the following experiment in the field of attention research. In this particular area there are some factors of importance that appear to modify participants' response ...
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17 views

Sample size for group comparison

I am collecting data from 3 different population groups (islands) and within each, comparing children from class 1 from 10-14 schools between two groups - those who completed kindergarten, those who ...
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1answer
23 views

How to calculate critical values for Dunnett procedure given alpha, df1 and df2

I am looking for an R function that can calculate critical values for a Dunnett multiple comparison procedure for any family-wise error rate and degrees of freedoms. In short, I need similar ...
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101 views

What does an error in ANOVA indicate?

When I came across ANOVA, the instructor talked about df(Error), ss(Error), etc. What do these error terms indicate? Do error terms differ for two-way ANOVA with dependent and independent variables? ...
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Can one manipulate data to demonstrate the power of the analysis?

I was asked this question about the demonstration of power. There are two groups of data, say control and treatment. If conducting a test( say a linear regression including other factors, but the ...
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14 views

ANOVA: Why residuals are uncorrelated with group means?

If I want to compare group means $\bar Y_1, \bar Y_2, \dots, \bar Y_L$ of a numeric variable $Y$ across the $L$ levels $x_1, \dots, x_L$ of a categorical variable $X$ in terms of R-squared, then I can ...
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23 views

Two-way ANOVA: negative interaction sum of squares?

I am doing a two-way ANOVA. The two variables are both categorical, one with 3 and the other with 2 categories. The count for each category is not equal. The data (only category means) is here: ...
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33 views

Identical SEs for all slopes in a regression on a factor

I'm relatively new to R and stats, and I just encountered a situation that I haven't before. I ran an lm (in R) with species richness as the response variable and elevation level (I have five of them ...
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10 views

One way ANOVA in R given Mean, SD, sample size only? [duplicate]

I am trying to run a one way ANOVA on some data. One factor, 4 levels. I only have mean, SD, and sample sizes to work with. Is there a way to do this in R?
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Addressing a mixed design analysis of variance when only one of the two groups went under repeated measures?

so essentially I have 2 groups (A and B, A is a control, and B can be referred to the "expert" group), and group B went under a specific training program (two times points, one prior to the training, ...
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20 views

One way between subjects ANOVA

I am planning to use a one way between subjects ANOVA to test for a difference of compassion between three different groups My question is how many participants would i need to collect data from and ...
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15 views

When do contr.sum and contr.treatment give the same ANOVA results?

If using the default contr.treatment setting in R, the Type III SS are supposedly incorrect. I've been trying to figure out when this is the case, and to what extent it matters. However, on a sample ...
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37 views

Statistical comparison between two curves

I have two time course experiments of the same study, and I want to determine if the time course curve is statistically significant or not. Let's say I treated a group of people with drug A, measure ...
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1answer
45 views

how to perform ANOVA in R on a very big matrix?

I have a very big data and I would like to perform multi comparison test. However, I must firstly perform ANOVA to be able to calculate p-value etc There are a lot of posts but none of them ...
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20 views

How to identify items answered differently by some factors such as male vs. female?

I want to do something like this: Variable: students (undergraduate, master students, and PhD students) Research instrument: XXXX (20 items) Reporting: The ANOVA analysis suggested that there is no ...
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12 views

Description of how the variance in `Y` changes with the discrete variable `X`?

Let Y be a continuous response variable and X be a discrete explanatory variable. I am interested in developing a statistical ...
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13 views

Understanding Results of ANOVA

I ran a two-factor ANOVA, where I'm looking at the time it takes to type a word. The data was split up by what type of task it took place in (6 tasks) and where the word was (outside/middle). For each ...
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63 views

Is it appropriate to do an ANOVA on a feature selected via inspecting PCA results?

I've been given a dataset consisting of 8 dimensional feature vectors for 4 classes of objects. I was asked to find the features that best distinguish the classes, and write up a short report. My ...
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58 views

Calculating the “critical value” for F test

I'm following along here: http://reliawiki.org/index.php/Multiple_Linear_Regression_Analysis#Calculation_of_the_Statistic I've successfully made all of the calculations up to $f_0=211.9$. Now I need ...
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18 views

Nonlinear form of ANCOVA?

I would like to compare a control group against a test group using something like ANCOVA. However, the covariates are not simple, as some items may have already been increasing with time, others ...
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21 views

Repeated measures for more than one variables

I wish to check if the covariate IVs $X_1$, $X_2$, $X_3$, have a significant effect in the way that the DVs $Y_1$, $Y_2$, $Y_3$ differentiates over time between two time points (2012, 2013). I have ...
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7 views

ANOVA table for alpha latice design?

I have my trail in alpha lattice design with three replications, 32 blocks in each replication, 10 plots per block, and with 320 treatment, please suggest to me an ANOVA model for this analysis.
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11 views

Hierarchical, nested, or ordered? Words in sentences, sentences in stories

I have an experiment where in one condition participants read stories, in another condition they read unrelated sentences, and in the last condition they read unrelated words. [Sentences were chopped ...
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15 views

Is ANOVA just a panel data model with dummy variables for group?

This might be a silly question, but I'm confused why ANOVA is different from a panel data model, with dummy variables for group, and inference on the coefficients on the dummy variables. Is this what ...
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12 views

How to measure order effects in SPSS?

I need to measure the order effects for my data. I have four questionnaires that were counterbalanced, which lead to 4 different orders. However, for one questionnaire, there are two subscales, ...
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51 views

Can a one-way ANOVA be performed in these circumstances

I am supporting a psychology experiment, and having problems analyzing some of the data. By way of background, I’m a programmer at a research organization who’s taken several stat courses recently. ...
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1answer
54 views

Compare linear models with and without an interaction effect

I want to compare the following two linear models: model 1: y = mean + A + B model 2: y = mean + A + A*B Is model 2 equivalent to y = mean + A + B + A*B? Can I ...
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8 views

Which type of test is better to compare difference of one independent variable (3 groups and one control) on a repeated measures experiment?

I have a group of 100 classroom participants, all who have taken a course that included four different lessons (from a single unit). Three lessons were taught each using a different form of ...
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10 views

Fully crossed repeated measure power

I would like to do some a priori power estimation to see what type of sample size I'd need for an experiment. It's a fully crossed 2x2x2 repeated measures design. There are 3 factors with two levels ...
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1answer
59 views

Do the different levels of treatment in a completely randomized design come from different population?

Suppose in a completely randomized design , a treatment A have four levels. When we check whether the means of four levels are statistically significant ,i.e., $$H_0:\mu_1=\mu_2=\mu_3=\mu_4$$ ...
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31 views

How is T-test identical to ANOVA?

I wondered if I need to use T-test or ANOVA in case of testing two groups for their mean equality and got a response that these two tests give identical results. I have checked, running experiments, ...
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32 views

One-way ANOVA and tongue testing

I have a pretty basic question about using a one-way ANOVA. I am performing an oral tribology experiment on pig tongues which basically means I am testing the friction of various mouthwash products ...
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Which is the difference between conventional 2-way repeated measures ANOVA and mixed effect ANOVA?

Assuming I have two within-subjects factors (Xw1 and Xw2) for my experimental design I can therefore perform two way repeated measures ANOVA using the conventional procedure in R ...
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After reducing data, ANOVA doesn't reject the null hypothesis

Previously ANOVA was working well on my results with a bigger dataset. Now, after reducing data, it always accepts null hypothesis. However for my thesis work I need to show the significant ...