Questions tagged [split-plot]

An experimental design used in situations where one factor can be changed more easily than another one. It's also called "mixed design" because it involves between-subject (hard to change) and within-subject (aka repeated measures; easy to change) factors.

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Correctly specify nested error structure for a split-plot ANOVA

I would like to check we are thinking about an approriate model structure for an experiment we have run, and whether I have specified this correctly in R. I have data from an experiment using plants ...
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It should be analyzed as Split-plot design or split-split plot design?

I have a field experiment with 4 blocks as shown in figure (1 block shown). I want to see the effects of Plant desity, spacing and irrigation. I am not sure how to analyze it. Should it be treated as ...
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What is the correct data structure for a Split-Plot design?

I was reading about split-plot designs and found some references that say the blocks (i.e. main plots) are 'nested' within the main plot treatment factors (left), but other references that say the ...
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Unbounded variance components for split-plot, RCBD, repeated over several years

I have a Randomized Complete Block design with 2 factors, replicated over 4 blocks and repeated over 4 years. Each block has 9 plots and each plot is divided into 2 subplots. The main-plot factor has ...
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A curious clinical trial design - What is the type / name of this rare methodology?

There is this split-mouth randomized clinical trial, in which one side of the mouth receives a particular treatment, and the other side receives another treatment (usually used as the control ...
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Power, split plot designs, and mixed models

My teammate and I are trying to determine the best way to allocated limited resources (shade cloth and fencing) in an experiment. We are considering 2 factors: light availability (2 levels) and water ...
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7 votes
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What is the specific issue with using count data for ANOVA tests

I'm running a study with a between-groups component and a within-groups component, with a predictor that is count data. I was planning on using split-plot ANOVA to analyze this, but after seeing lots ...
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Mixed Effect Model - Nested Block labelling

My data has 5 blocks . Within each block, the same 3 sub-blocks (1,2,3)are applied to each individual. I want to examine the the effects of the blocks and sub-...
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Change parameters block-wise in experiment design?

Is it possible to generate an experiment design which changes a parameter block-wise? To be more precise what I would like to do: Run an experiment with a certain parameter (humidity) fixed which is ...
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No significance in the multivariate tests

Hope this question is not too stupid. I haven't taken the MANOVA course yet, but I need to figure out a problem right now. I am running a mix-model MANCOVA on SPSS. I have no significance in the ...
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Bayesian Split-Plot Design with heterogenous Variances / Kruschke / JAGS / ANOVA

I try to analyze a split-plot design and try to get my head around the code. My problem is that we were only able to gather a convenience sample of patients grouped into 11 different disorders at 2 ...
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How do I decide which experimental design to use in order to properly analyse the collected data?

I'm struggling to understand which experimental design I should use. I used factorial design in most of my experiment but i recently read a document where it mention that the precision of some main ...
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How to code a two-way ANOVA with split-plot design using R?

I am analyzing a split-plot land-use experiment and I am stuck on the R code. We used four sites and on each site the following design: We conducted a full-factorial design with two factors (land-...
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significance tests for mixed models?

I have a two-factor split-plot design experiment looking at biomass across a large region and in the presence or absence of fire. Biomass is measured in 5 different forests and each forest has two ...
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Type of ANOVA to use: Split-Plot, Nested … or others? Water quality project

I was wondering if I could get some help in determining the correct ANOVA analysis to run on a water quality project in am working on. My dataset have the following variables: Habitat Type (fixed) (...
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Split plot with RBCD in R: Are inferences valid when output reports some effects are not estimable?

Data are from an agricultural experiment and are the proportion of turnips damaged by cabbage maggot in different insecticide treatments (note preliminary investigation suggested data were ...
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Experimental Design with two treatment levels, random effects, and technical constraints

I'm trying to plan an experiment and the experimental design is giving me headaches because it's too complex to wrap my only-statistics-101-capable head around. Basically I want to subject plants of ...
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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 replications. They have been either conventionally or organically ...
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Split plot design with psudo replicates

I am working on a project and need to analyze data that I know is an example of a split plot design but I am having trouble setting the model up correctly. Here's the situation: A bakery is testing ...
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Analyzing Split-plot design [closed]

Am new to R. Am teaching myself and I got stuck with a data I wish to analyze. The design is a split plot and I have the following variables: Rep, Mainplot, Subplot, Weeks after Planting and measure ...
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How to describe a split-plot ordinal logistic regression

I am having difficulties reporting a split-plot ordinal logistic regression. I get the concept of ordinal logistic regression involving a categorical representation of a latent continuous variable, ...
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DoE with correlated runs. Possible solutions?

I would like to create an optimal experimatal design (DoE) for a machine which will be used to produce 20 results in batch mode to find the most important factors which do have an impact on certain ...
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Cohen's d in split-plot experiments

There is some demand for effect-size measures in doing post hoc analyses, and I am trying to decide whether to provide for this or not in an R package of mine. If I do, I would concentrate on Cohen's $...
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How to study split-plot design

Is it possible to study a split-plot design with a mixed model? I've seen a related question so I guess it is doable in general. Is there any certain function or procedure I can use? Or can you give ...
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Constrain a number of factors in Design of Experiments

I have multiple factors with multiple levels, for which I am trying design of experiments. Here is an example: ...
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Split Plot Analysis Interpretation

This is the R output I was given for a split plot analysis. I think I'm on the right track with my interpretation, but I want to make sure. Q1: What should you look at first? If the treatment*year ...
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Split split plot ANOVA table: r = replicate or block?

I have seen various ANOVA tables for analysis of split split plot designs, and some have the first term ''r'' defined as the block while others have it as the replicate. This is confusing to me, as ...
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Existing very detailed derivation of sum of squares error for split-plot ANOVA?

Since a few years i'm trying to group all very detailed derivations of all (very common) existing ANOVA in a document. For some it's a real pain in the a** to do this work. Now i'm near an ...
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What is the difference between a mixed-design (split-plot) ANOVA and a linear mixed-effects model?

My understanding is that in a mixed-design ANOVA, the between-subjects is the fixed effects factor and the within-subjects variable is the random effects factor. Not sure if that is any different from ...
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Interpretation of R output for mixed ANOVA model

I had to do a mixed ANOVA. How can I interpret the results? Power (high power / low power) is the within factor. interaction (...
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3 votes
2 answers
715 views

Do Likelihood Ratio Tests "respect hierarchy" in linear mixed models?

The following example from the JSS paper on pkbrtest shows an LRT meant to test for the effect of the whole-plot treatment (harvest): ...
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Random Effects Design Matrix

I'm trying to move away from ANOVA/t-tests and get a better understanding of GLMs. I am doing my statistical analysis in R using function lm (only fixed effects) and lmer (+ random effects). I also ...
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Split plot in time mixed-effect model in R

I am new to this website, to r, and to mixed effect models so apologise in advance if I exhibit a degree of ignorance. I am looking for help of how to fit a model for an experiment that I have done. ...
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Generate Grouped Data with Exact Correlations, Means, and SD

I want to generate data with the following constraints. There is one factor and two numeric variables. Note that the desired mean structure is broken down by factor, which is what makes this a ...
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3 votes
1 answer
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Setting up a mixed model or a split-plot ANOVA for an experiment with male/female fishes in replicated tanks

I am designing an experiment with juvenile fishes. There are 12 replicated tanks. In each of the first 6 tanks there is a even mix of male and female fish (100 of each sex in each tank); 3 of these ...
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Is it possible to have covariates for different tasks within an split-plot analysis?

I am conducting an experiment which looks at between-within subjects. There are two groups (participants will either use an iphone and android in the experiment) and they both have 4 short tasks to ...
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Transformation of raw-scores to proportions for a split-plot ANOVA [closed]

I have performed a 2 x 2 x (2) split-plot analysis on raw scores of a questionnaire. The questionnaire was taken twice by participants, once before and once after the intervention in question. A ...
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Split plot analysis

I am analyzing my experiment and I have encountered a doubt. It is a split plot design, agriculture experiment where main plot is received four different treatments (incl. control) and four subplots ...
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How to combine in a (fractional) factorial design model the blocking effect with a treatment (package planor)

For my greenhouse experiment with potted trees, I am planing a fractional factorial design. The experiment has six factors (treatments) each with two factor-levels, and I want to use a model/package, ...
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Mixed model random-effect structure for repeated measures, split plot design in R (nlme or lme4)

I am seeking advice on structuring the random-effects component of a mixed model in R. The data that I am modeling come from an ecological experiment with a repeatedly-measured split-plot design. At ...
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911 views

Mixed model for three factors (split split plot design) with proportions as response

I am struggling with the analysis of a data set from an experiment done as follows: I have 5 blocks (that work as replicates) and each one of them was divided into two part (so split block), to each ...
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How to interpret the split plot anova result? Please explain to me about split plot anova

I'am analyzing an artcle , it said that split plot anova was conducted to asses the impact of two different interventions on student scores on achievement test, across two time period (pre ...
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How to manage time dependent factors in design of experiment

I am designing an experiment in a semiconductor context. Briefly: the performance (i.e. etched material) of a tool (CMP - chemical mechanical polishing) used in the manufacturing of silicon wafers ...
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3 votes
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Repeated measures on split plot design with blocking

This is the first time I'm posting a question here. I have regularly been using the questions and answers here as example solutions for my problems, and searching has always helped me figure things ...
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Experimental Design: Split Plot with 2 whole plot factors and 1 subplot factor. Understanding Error Terms

I usually have a little bit better experimental design, but this experiment has already been planted and can't be changed. Instead of being a true split plot design, in which case I would use ssp....
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Is it possible to compute some measure of effect size from four means from a split-plot (both within- and between-subjects) 2x2 design?

For a meta-analysis, we are interested in the comparison of two groups. From the articles, we can extract four means: two baseline measures on one of our dependent variables, and two measures ...
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Split-plot analysis with four factors in SAS

I'm trying to correctly model a split-plot design with more than two factors (specifically, four) in SAS. I'm interested in an example from Design and Analysis of Experiments (Montgomery , 8th Ed.), ...
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Repeated measures assistance needed

Disclaimer - I am not particularly adept at stats and have a relatively complicated design. I apologize in advance for my ignorance. Looking forward to any help I can get! Here goes... I have 2 ...
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3 votes
1 answer
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How to define a between variable is random effect in Anova in R? [closed]

I am using 'Anova' function in 'car' package to analyze plot - split experimental data. I have 1 between group, and 2 within group variables, so it is SPFp.qr analysis. The problem is, the between ...
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4 votes
1 answer
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Mixed-design ANOVA or one-way ANOVA with delta values

I have an experiment with one independent variable with 4 levels (4 different treatments) and 1 dependent variable which was measured twice - before and after the treatment (repeated measures). I ...
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