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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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39 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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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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26 views

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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34 views

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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27 views

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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44 views

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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8 views

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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32 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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155 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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Is there a statistical test for this experiment?

We have developed a Benders decomposition algorithm for an inventory-routing problem. We have considered that optimality and feasibility gaps could get different values. Therefore, choosing an ...
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1answer
20 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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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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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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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
25 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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15 views

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
362 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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36 views

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
404 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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142 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
97 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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310 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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133 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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238 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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81 views

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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78 views

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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788 views

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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267 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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319 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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394 views

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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275 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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265 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, ...
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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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223 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
229 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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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 ...
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1answer
174 views

Experimental design vs factorial design

During my study about experimental design, I detect from some examples that factorial design is a sub-step in an experimental design. However till now the idea seems not fully clear for me. What is ...
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284 views

Main effects in Minitab

I have a multilevel factorial design. I use Minitab to study and analyze this design. One of the outcome of such study is the main effect plot. I get the following : As I am new to design of ...
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366 views

Experimental design when having continuous factors

I am studying about experimental design. I understand some of its general steps. I still have a small question: Can we apply experimental design when having continuous factors ? What I mean by a ...
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1k views

Automated calculation of a fractional factorial design with 9 factors

In my research I want to employ a choice experiment using factorial design. However, I struggle to derive a fractional design from the full factorial design. There are 9 factors on 2 levels, which ...
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2 questions about fractional factorial design- efficiency and analysis

We're piloting a multiple variable testing program at my company. For starters, we're looking at a test with 3 factors (a, b, c), 2 levels (-1,+1) each. Based on research from several standard texts, ...