Questions tagged [fractional-factorial]
Experimental designs that use only a subset of possible factor combinations. Typically, some factors are intentionally confounded w/ some interactions, making the interactions impossible to estimate, but requiring a smaller N for the study.
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Do I want a mixed model for fractional factorial designs?
I have created a d-efficient fractional factorial design of 48 combinations from a total of 192 possible combinations (4x2x2x3x2x2).
To estimate the model, I plan to have 4 runs in 12 blocks and 40 ...
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How to generate a design for a response surface with a discrete input random variable?
I'm trying to generate a design of experiments for fitting a response surface for a quantity $Y$ such that, $Y = f(X_1, ..., X_6)$. I'm open to a factorial design as well as a random design. $X_1,..., ...
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Advantages/disadvantages of fractional factorial design vs completely randomized design
I'm new to the design of experiments (DoE) and will be running a screening experiment to estimate the effect of a large number of binary independent variables (approximately 10) on a single continuous ...
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53 views
How to analyze experiment (based on DoE and via mixed model)?
I am about to deploy my DoE which is based on six parameters with two whole plots: Temperature and relative humidity. The experiment aims at studying a sensor due to the presence of several gases (...
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What is a “regular” fractional factorial (2-level)?
What is the difference between a regular fractional factorial design and a non-regular fractional factorial design? I found it several times but especially in the FrF2-package.
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How to study a fractional factorial design? [closed]
I wonder why a DoE/fractional factorial design isn't studied with the help of a linear mixed model? Or an Anova?
How to analyze it in general is e.g. given here.
Background: I will study several gas ...
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21 views
Interpreting interaction effects in Factorial design
I have factor1 with 2 levels fully crossed with factor2 (5 levels). Now samples are collected from same experimental units at 6 different times. Time is used as within-subject variable. When I run ...
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Full factorial repeated measures ANOVA
I have a Full factorial design where factor1 has 2 levels and factor2 has 5 levels fully crossed (10 treatments in total). Then the samples are collected from same individuals (plots) at 6 different ...
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“Incomplete Design” Problem: 2(between) x 2(within) x 2(within--but only in one between group!)
Problem:
I am trying to analyze an experiment with the design in the title:
2(between) x 2(within) x 2(within--but only manipulated in one group)
My initial hunch was to run two separate 2 (between)...
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1answer
73 views
Fractional factorial DOE in pythonDOE problem
I need to do a fractional factorial DOE analysis for my data that will come at the end of the post as image, I am using this code in python . It would need to pip install diversipy if you haven't ...
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How do I do a power analysis for a fractional factorial design?
I want to do a power analysis for my 3x2x2 design, but I am not using the full factorial design, but rather a fractional one, so instead of using the full 12 groups, I actually only have 6. I was ...
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Multi-level factor design of experiments
How should I select interactions in order to be able to encode multi-level features using interactions of main features in my design?
I'm wanting to create an experimental design to be used to create ...
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logistic and anova
In here, you can see original data.
My data is $4\times3\times3\times2$ completely randomized design experiment data.
I want to model the probability of survival in terms of the stimulus variables.
...
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Taguchi Designs for differential gene expression
I plan to do a differential gene expression using RT-qPCR of 10 genes on 3 strains cultured in different enviormental conditions of 3 factors (2 levels each one). In order to do so, I want to follow a ...
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Specifying the bandwidth parameter for Local Whittle estimation
In every Local Whittle function I have seen I have to set bandwith parameter usually denoted m such that
m = floor(1+T^delta).
I am interested in the delta, how do I choose what value to put in the ...
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1answer
40 views
Factorial design name
I was just wondering, as I have been using ordinary least squares regression a lot lately, could anyone explain why a factorial design called a "factorial" design?
What part of the calculation is ...
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1answer
210 views
How to calculate (standardized) orthogonal contrast coding in R?
I want to determine efficient fractional factorial designs and blocked designs for factorial surveys and am using the R library AlgDesign. The criteria I'm using to determine if a design is efficient ...
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1answer
21 views
Adding center points in $2^k$ models
I'm not sure I understand this concept. In $2^k$ designs, the independent variables have only two values and are coded as either being -1 (low value) or +1 (high value).
We can add a center point to ...
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1answer
29 views
Comparison of treatment differences in fully factorial design
I have a dataset from a fully factorial experiment aimed at looking at mortality rates in fish depending on chemical additions.
There are manipulations of Buffers (2 types), Nutrients (Ca and Mg) ...
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1answer
44 views
Constrained design of experiments
I would like to conduct a 2-level fractional factorial experimental design on 8 factors. I used the FrF2 package in R to do so. I have capacity to do roughly 30 experiments, so I selected a resolution ...
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Factorial experiment design with incompatible levels in IVs
Is it safe to run a Factorial ANOVA if you cannot collect data for some cells?
Scenario: There are two independent variables, and one dependent variable.
All independent variables are nominal:
D (...
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1answer
14 views
Does a factorial design work for factors that have discrete levels, but can't be classified as “high” or “low”?
I have eight factors, four with 2 levels and four with 3 levels. These levels are not "high" and "low" in the sense that they can be turned off and on—but are instead things like "voiced" and "...
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Simulate responses for fractional factorial design
I want to simulate responses for fractional factorial design.
As an input for simulation I want to use estimated effect sizes of main factors and some interactions.
I know there is a formula for ...
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1answer
27 views
Central composite design
I'm a data scientist who has not used central composite design before, I only heard of it, but I'm not able to grasp for what it can be used and how it can be used.
Can someone please explain this to ...
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Arbitrary combination of levels in fractional factorial Experiments
I have a problem figuring out the properties of an existing fractional factorial experiment. I basically have the following samples 1-6 and the properties A-D:
...
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1answer
414 views
DOE for evaluating a factor with more than 2 levels
I am new to designing experiments. I like the simplicity of 2-level, fractional factorial designs for screening what factors and interactions are important. However, I often conduct competitive ...
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When do three-factor interactions or higher be assumed negligible?
I am referring to fractional factorial designs where some two-factor interactions are aliased with three factor-interactions, and three-factor interactions are aliased together.
To simplify the ...
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1answer
496 views
Fractional Factorial design for 3 factorial
I would like to be assisted on how to go about choosing the treatments to work with in a fractional factorial the following scenario.
I have 3 factors ie 3 feeding intervals, 3 larval densities and 3 ...
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192 views
How to quantify the “resolution” of “Fractional factorial design”?
The Design Expert software gives me the picture of resolution for the fractional factorial design, in which Resolution III, IV and V are most critical.
But can I ask, how can I determine the ...
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1answer
129 views
Design of Experiments for Baking
I am very new to design of experiments concept. I would like to design an experiment to understand the relationship between input parameters like amount of various ingredients, cooking temperature, ...
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1answer
366 views
How to set up a mixed model with partially crossed factor levels
I would need some help with the analysis of a soil data set. The variable Ms was measured with n=5 over several campaigns (7 levels; i, ii, iii...) throughout a year on an agricultural field that ...
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1answer
166 views
Incomplete treatments in Fractional Factorial Designs
I'm trying to analize a chemical experiment with four factors or independent variables. Initially each factor had three levels, so i proposed a $3^4$ factorial design; the problem was that all the ...
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253 views
2x2x2 (reduced) design to study main effects
I'm at the point of conducting a 2x2x2 factorial design to study corporate adoption decisions. I am only interested in the main effects and run a ANCOVA. This experiment is only one part of a bigger ...
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1answer
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confounding ABC in factorial experiment
Consider a $ 2^3 $ factorial design lay out in 2 blocks ,each of size 4, as follows
Block I: {1,a,b,c}
Block II: {ab,ac,bc,abc}
Here,the treatments combinations are written in Yate's notation. ...
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DoE - full factorial with less levels or fractional factorial with more levels?
I am planning on doing a variance components analysis (random effects anova). I'm wondering if anyone has any advice regarding balancing the number of levels to include in the design vs. the type of ...
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Question regarding a factorial design and the main effect of one of its factor
Suppose we consider the following $2^4$ factorial design with factors A, B, C and D in the usual order.
$Block1 - (0,0,0,0),(0,1,0,1),(1,0,1,0),(1,1,1,1),(1,1,0,1),(0,0,1,0).$
$Block2 - (0,0,1,1),(...
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Algorithm for generating a multi-level fractional factorial design
I would like to perform some black box testing on some software that takes a large number of input variables. These variables can have some interactions (either intentional or non-intentional) so I ...
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279 views
Optimum approximate theory D-Optimal design
I am using optFederov, from package AlgDesign, to create D-Optimial designs. However, I am a bit confused on what measure to use as efficiency measure. I'd like to use D-Optimal but I don't know which ...
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1answer
356 views
Experimental (factorial) design not exploiting the variance
I want to construct a design to use Choice Based Conjoint Analysis. I want to focus on D-Optimality, for that reason I use the R package AlgDesign which uses Fedorov Algorithm. I create 7 attributes ...
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How to interpret Experimental design created by AlgDesign?
I'm doing an experimental study of 5 factors with a different amount of levels in each. More specifically: 9, 13, 12, 6 & 15.
Using the AlgDesign library in R, i ran the following syntax to ...
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1answer
325 views
Machine Learning for optimization of configuration file
For my master's thesis I am using a 3rd party program (SExtractor) in addition to a python pipeline to work with astronomical image data. SExtractor takes a configuration file with numerous parameters ...
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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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Fractional factorial designs: lower $p$ vs. more replications
If you were to choose between a 2(X-1) with only one replication or a 2(X-2) with two replications, what would be preferred and why? The goal is to both predict the values of the effect parameters as ...
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How do I analyze interaction in two-factor factorial data when sample size is not given?
I am looking at two-factor factorial data where the response variable is number of cancer cells after an experiment is performed.
The two-factors are:
Factor A, which has a = 2 levels: "...
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235 views
True replicates or nested data ANOVA - only one experimental unit per condition
I'm in materials science. I have a fractional factorial experiment. I am investigating the main effect of various treatments on a measured response. The exact details are probably not needed to ...
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1answer
244 views
How can I fit a polynomial given some prior knowledge but fewer observations than coefficients?
I want to fit a second degree polynomial to data from a fractional factorial design in five dimensions. Because of the cost of trials, I am initially only going to do eight runs. So I have fewer ...
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What methods can I use for parameter estimation of fractional factorial design?
I've been asked to estimate the parameters of fractional factorial design model which is normally estimated using least square method in R (code is lm).
Question: Is it possible to change the least ...
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Generating a response surface from a fractionated design
Is it possible and valid to generate a response surface through augmentation of a fractionated factorial design, where all main effects and two factor interactions have no bias from any other main ...
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58 views
Intuition to the Resolution of a fractional factorial design
In design of experiments, is there an intuitive way to understand (and explain) the idea of the "resolution" of the design?
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1answer
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Is it possible to determine how many effects I can estimate in a least squares problem just by looking at the correlation matrix?
I currently have a model matrix $X$ with $6$ columns, which is being used for a factorial design problem, with each column associated with an effect. The ultimate goal is to be able to estimate as ...
