Questions tagged [anova]

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 to caculate the two way ANOVA table “without” interaction term [closed]

A bank likes to know whether the amount of loans granted to customs is associated with branch offices and customer groups(Groups A : high-risk customers;Group B: low -risk customers):Three replicates ...
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Kruskal–Wallis one-way analysis of variance is related to what kind of regression?

One-way anova is similar to regular linear regression because both use the F-test which involves sums of squares among other reasons. Is Kruskal–Wallis one-way analysis of variance similar to some ...
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How to compare data?

I have data for the size of rocks for two independent locations, A and B. Data lists rock size from smallest to largest (shown by yellow column) Red column shows the percentage of rocks under that ...
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Regression F and t statistic

My understanding was that, to make a hypothesis test of a linear combination of regression parameters (e.g. of the type $\beta_1+2\beta_2=0$), you should use a decision rule of the form $|T| = \left| ...
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ANOVA with +Error shows incomplete summary table and no diagnostic plots

I want to test with my data weather species richness (Y) is dependent on Treatment (A = factor with two Levels) and if it changes over the years (B = factor with three Levels). The plots were repeated ...
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Am I right to think I can use ANOVAs in exploratory - inductive research?

• I am busy writing a research thesis on NAFTA comparing Canada and Mexico on their (1st) behaviors towards sustainable development (in each country), (2nd) their relationship to the concept of ...
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Differences between years in time series data

I have a multiyear time series dataset detailing the concentration of environmental contaminant over time. and I need to determine if there is a significant difference between the yearly means. In ...
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Two way repeated measures with baseline and multiple time-points

We have a repeated measures experiment. Each person had their temperature measured once before, and every minute (for 15 minutes) after two different interventions. As each of the two different ...
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Type of ANOVA that is appropriate to use in this Data

We are currently conducting a small study and have very small background in Statistical Analysis. We conducted some experiments and have gathered some data. Can anyone help me in identifying what type ...
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ANOVA-like analysis for geometric distribution

I have a dataset (>10,000 samples total) that strongly appears to be geometrically distributed. For this dataset I have a way of partitioning that makes sense theoretically and I would like to know if ...
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Which statistical test : Anova or T-Test for between subject experiment (repeated measures ) with one IV with two levels( control and treatment)

It's a between-subject design with a control group and a treatment group with 50 people each. Each participant undergoes 100 trails. (repeated measures). So the only within-subject factor is the ...
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Results Interpretation [closed]

Can someone help me interpret the results of this ANOVA, or tell me how to do it ?
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Coefficient of Variation for beween groups [closed]

I am currently looking at doing an ANOVA to check for evidence of differences between the groups mean, part of what I am doing I will be reporting the CV (sd/mean) for quantifying the amount of ...
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Using Anova at a Correlational study [closed]

I am conducting a correlational study and, additionally, I would like to measure gender differences. Should I use an Anova? There will be two groups and each one of them will have both genders.
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How do I analyze a three factor ANOVA without replication in R?

This summer, I conducted a growth chamber experiment testing the effects of the projected climate change conditions on the growth and survival of newly germinated seedlings of Acadian forest tree ...
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Can I use the Anova (type II) to test significance in my negative binomial regression?

I have fitted a binomial regression (glm.nb using the MASS package) to my data. I have two questions and would be very thankfull if you could answer any of them: 1a) Can I use the Anova (type II, ...
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ANOVA assumptions without raw data?

I have several mean values (with standard deviations and sample sizes) that I would like to compare. However, I do not have the raw data. Is there a way to test the assumptions of ANOVA in this case? ...
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How do I analyse datasets with large and small values, three explanatory variables, and is not normally distributed?

I have been trying to figure out the best way to analyse my data for some time and I am just working myself into a pit of confusion. Briefly, I have taken a whole bunch of physiological measurements ...
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Deciding to use an ANOVA model with interactions or testing significance without interaction

I know this is a widely discussed topic and there are numerous sources and examples. However, most of the statistical jargon goes over my head. I was hoping that someone could simply explain my ...
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Is it possible to do a post-hoc test on a factorial ANOVA?

Is it possible to do a post-hoc test on a factorial ANOVA? I have three independent variables (sex, age and depth) and then a single dependent value (BV/TV). This is the R script I've been using for ...
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Analysing number of errors with ANOVA in R

I have the following dataset ...
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Statistically significant means with small mean difference

I ran an ANOVA on 3 sample sets with means 7.8, 8, and 7.9. The sample with a mean of 8 was statistically different than the other two. The sample size for each mean=200 and 95 confidence level. Why ...
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Compute ANOVA on multivariate regression results

I’ve some problem understanding why ANOVA is applied after regression coefficients calculation. In detail my question arise from this problem; I've been able to solve it numerically following this ...
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How to carry out 3 factor repeated measures ANOVA in R? [closed]

I have 3 factors Search Type(Feature or Conjunction), Number of Distractors(4,16,32, or 64), and Target(Absent or Present)and I want to run a repeated measure ANOVA in R.
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appropriate error term for a randomized complete block design, possible split plot in time, with subsamples (in SAS PROC MIXED))

I am analyzing the results of an agricultural experiment, as follows: Plots are laid out in a randomized complete block design with 3 reps. They have been either conventionally or organically managed ...
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Non-normal data: lower p-value from Kruskal-Wallis than ANOVA

I am currently working with data in which I have one continuous variable (speed) and a categorical variable (3 different populations, with n ranging from 13 to 30 for each group). I have determined ...
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Theory: When to use one multi-factorial ANOVA vs. many one-factorial ANOVAs

I was recently peer reviewing a paper that used statistical tests in an odd way that didn't seem right to me. However, I'm not an expert so just wanted to talk theoretically about some of the things I ...
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Two Factor ANOVA with different sample sizes but similar variances

I gave an educational intervention to Spanish speaking and English speaking students. I gave a pre and post test to these students. Due to certain issues I was not able to identify students with their ...
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Including a count data covariate into a 3 way factorial robust ANOVA and outliers in R

I have a three way ANOVA testing the effect of phosphorus (5 rates) x water-logging x cultivar (one water-logging tolerant, one not) on shoot biomass. There are four reps. I'm using R to do the ...
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method for difference score prediction

I am currently working on a longitudinal analysis (with only 2 time measurements, T1 and T2). In this non-randomized data, I have 2 time measurements of fasting glucose as my outcome, i.e. Y1 and Y2 ...
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Is this the appropriate way to conduct an ANOVA on this data?

I have collected data on 216 individuals. I measured the concentration of the same 7 Substances in each individual, represented by Sub1:Sub7. The concentration of these Substances may be different in ...
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What are the appropriate ANOVA and classification methods to use for this data set?

I have collected data on 293 individuals. I measured the concentration of the same 7 Substances in each individual, represented by ...
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correlation or regression or ANOVA and ETA

I would like to test a hypothesis. Those organisations using PESTLE analysis have achieved a better gross profit. I have develope a table with independent variables (using PESTLE =1, not using ...
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Comparing linear regression models under violation of independence assumption

the basic setup is as follows: I have a continuous dependent variable (DV, 7 observations) and two continuous independent variables (IV1 & IV2). I would like to evaluate whether adding IV2 as ...
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Test - one-way ANOVA assumptions

I'm trying to solve some statistic problem, one of that requires to check if one way ANOVA assumption (normality) is satisfied. The slide provided say to proceed as below: hypothesis test $\frac{e_{...
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Mixed anova post-hoc analysis (when do we need to do t-test across all pairs?)

before I decided to ask my question, I actually find several existing questions that are very similar to mine but remain unanswered: Mixed ANOVA post hoc analysis (and multiple comparisons) Mixed ...
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Pairwise Comparisons for Rank Based rfit Models in emmeans

I recently found this package: https://journal.r-project.org/archive/2012-2/RJournal_2012-2_Kloke+McKean.pdf. I am utilizing this package for Robust Regression without having to resort to M or MM-...
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Using ANOVA to select number of knots for splines basis expansion

Imagine I want to fit a linear regression model of $Y$ over $X$. I have decided to use splines (lets say natural splines, but it shouldn't matter) to create a new design matrix $X'$ from my original $...
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Why does an ANOVA design matrix with a fictitious 0 observation allow for ANOVA with mean plus contrasts to be estimated?

I was reading Functional Data Analysis with R and MATLAB (Ramsay et. al., 2009) and they presented the following (functional) ANOVA model (but I'm ignoring the functional aspect; it doesn't appear ...
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Interaction is not significant in ANOVA, but significant in Regression, which is nonsense

Variables that I have: randomization (categorical): control / low / high sesdummy (categorical): low / high fairness (continuous) I wanted to see if there was an interaction effect between two ...
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Find the orthogonal contrasts of the sources of variations in the following design

I know the condition of what an orthogonal contrast is: the dot product of their coefficients should be zero. Plus if we are given a set of contrasts, they are supposed to be mutually orthogonal to ...
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Anova mixed- between and within

Hello my name is Francisco and i am having a big doubt in a statistical exercise in spss. that is i have two indpendent variables, each one with two level: sistem production: soil, substrate variaty:...
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2x2 ANOVA with trimmed means : uneven group sizes causing error message

I am doing a 2x2 independent measures ANOVA on trimmed means. I am using the WRS package to perform this robust ANOVA in R. I have two independent variables with two levels each. They split ...
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Find the orthogonal contrasts of the sources of variations in the following design

The question I know the condition of what an orthogonal contrast is: the dot product of their coefficients should be zero. Plus if we are given a set of contrasts, they are supposed to be mutually ...
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1answer
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How do I interpret the results of my ANOVA f-test?

I have a fairly simple question, I am struggling with how to interpret my f-test results and what they mean about the variables, Insta and Twitter. Model 1: ...
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hyp test: constant return to scale with Squared and interaction terms

I want to test if constant return to scale applies to my production function (modelA): log(y) = log(x1) + log(x2) + log(x1)^2 + log(x1)*log(x2) I have tried the following in r, but iam not sure if ...
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Help explaining to collegue problems with his data analysis for a pre-post group design

I'm currently reviewing a colleague's paper, and they have an intervention study (2x3 design) with 2 groups (therapy vs waitlist control) and 3 time points (pre-test, post-test, long-term follow-up). ...
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A one-way ANOVA for multiple comparison

Cheng, H., & Liu, S. (2019). Haptic Force Guided Sound Synthesis in Multisensory Virtual Reality (VR) Simulation for Rigid-Fluid Interaction. In 2019 IEEE Conference on Virtual Reality and 3D User ...
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T-test and ANOVA suggesting different results?

I'd like to start off by saying I am very much a beginner to statistical analyses, so I might be missing some key ideas here. Context: My study involves an experimental group and control group that ...