# 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.

91 questions
Filter by
Sorted by
Tagged with
20 views

### Dunnett's test for comparisons with Control - how to conduct ANOVA for 2 factors, as well as adjusting for different experimental designs?

From what I understand, before we conduct Dunnett's test for comparisons of treatments to a Control, we have to do ANOVA. However, for a 2-factor experiment, there seem to be a lot of problems to me. ...
• 53
1 vote
82 views

### Specifying a model with random effects for a strip-plot designed experiment in R

I am currently trying to understand the analysis of strip-plots (in R) and I came across the example described here (https://www.statforbiology.com/_statbookeng/a-brief-intro-to-mixed-models): ...
• 33
15 views

### Summary statistics (mean and standard error) of split plot nested design- using R

I have a study with a split plot design where every season (wet and dry) we sampled for 3 years at 8 sites. At each site (fixed factor), we have plots (nested within sites) and then we have subplots ...
33 views

### Split plot design - help with choosing the analysis

I have a split-plot design experiment with three levels (slope, then treatment within slope, then cages within each treatment), with the main response being a count of seedlings. South South ...
• 1
1 vote
69 views

### In R, how to analyze Strip-Plot Design when there are three factors?

I have one dataset like below ...
• 143
24 views

### Split-split-plot ANOVA analysis with missing values - correct model with three factors?

I am having trouble figuring out if my ANOVA model is correct. I am analyzing a split-split plot greenhouse study with shade as the main factor (n = 3 treatments), site as the sub-plot factor (n = 3 ...
285 views

### What is the correct lmer model formula for a Split Plot design?

I have a standard split-plot design, having the three predictors: A :: [ Categorical, Unordered, 2 Levels ] --> (1, 2) B :: [ Categorical, Unordered, 4 Levels ] --> (1, 2, 3, 4) C :: [ ...
1 vote
22 views

### Split block design with crossed main effects and a random effect in R

I am having trouble specifying a model in lme4. Your help with be greatly appreciated!! And please let me know if I can improve how I ask this question. I am looking at the impact of light, ...
• 11
1 vote
25 views

### Determining nested random effects using a generalized mixed linear model (in R)

I have a split-plot experiment, with irrigation as a main-plot factor (x2, Irr1 & Irr2) and fertilizer type (x4, F1-F4) as a split-plot factor. Within each experiment, each treatment is replicated ...
22 views

### Is mixed ANOVA the correct test for my experiment?

I'm new to statistics and maybe I went a little bit other my head for the experiment design of my bachelor thesis: I measured the turn angle of people dodging different objects in virtual reality. The ...
352 views

### Split-plot design analysis by Linear Mixed Models in R

I am trying to analyse data from a Split-Plot experiment by Linear Mixed Models with lme4 in R. The design consists of a whole-plot factor and two split-plot factors (see attached layout). Whole-plot ...
• 31
751 views

### Difference between blocking and split plot-design?

What is the difference between blocking in an experiment design and a split plot design?
• 3,493
46 views

### Can someone explain how to select the proper random effect when analyzing a split plot design in R?

I am struggling to understand the concept of assigning the random effect when using a mixed linear model to analyze my split-plot experiment in R. Below is the data I am working with. This should ...
120 views

### 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 ...
• 1,363
1 vote
44 views

### 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 ...
888 views

### 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 ...
• 439
41 views

### 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-...
• 1,226
1 vote
46 views

### 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 ...
• 3,493
1 vote
133 views

### 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 ...
• 11
1 vote
67 views

### 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 ...
42 views

### 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 ...
• 195
1 vote
281 views

### How to code a two-way ANOVA with split-plot design using R? [closed]

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-...
• 11
1 vote
60 views

### 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 ...
• 156
1 vote
69 views

### 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) (...
• 11
1 vote
55 views

### 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 ...
• 11
1 vote
47 views

### 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 ...
• 123
1 vote
98 views

### 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 ...
• 21
283 views

### 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 ...
1 vote
46 views

### 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 ...
• 11
1 vote
91 views

### 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, ...
• 2,053
1 vote
86 views

### 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 ...
• 131
57 views

### 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 \$...
• 20.8k
42 views

### 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 ...
• 3,493
54 views

### 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: ...
1 vote
225 views

### 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 ...
• 63
1 vote
2k views

### 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 ...
• 11
1 vote
120 views

### 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 ...
• 163
1 vote
242 views

### 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 ...
• 11
1 vote
387 views

### 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 (...
• 11
919 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): ...
• 5,427
5k views

### 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 ...
• 121
858 views

### 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. ...
221 views

### 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 ...
543 views

### 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 ...
• 51
1 vote
65 views

### 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 ...
1 vote
27 views

### 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 ...
• 2,053
1 vote
69 views

### 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 ...
• 145
1 vote
345 views

### 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, ...
• 11
654 views

### 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 ...
• 91