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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124 views

How to design a 2-level fractional factorial experiment given some prior knowledge

We're designing a trial to test four factors (call them A, B, C and ...
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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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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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140 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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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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281 views

Half-Normal Plot of Coefficients from Binary Factorial Experiments

After I wrote this all up I debated whether or not I should post it because I think I know the answer to this question (after looking at the two models I'd end up with), but since I don't really know ...
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538 views

Control group in Incomplete Factorial Design

here, in title of Incomplete Factorial Design, it is written that " it is actually impossible to implement a group that simultaneously has several levels of treatment factors and receives no ...
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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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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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13 views

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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60 views

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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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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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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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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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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43 views

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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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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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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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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363 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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61 views

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, ...
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34 views

$2^k 3^l$ factorial design

I'm looking for a reference for a $2^k 3^l$ fractional factorial design. Do such things exist? I could use a D-optimal but would prefer a clean aliasing structure. Any tips on software also good. Use ...
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137 views

Comparing distributions from a factorial design

I have the following experimental design: I have six animals, where three received treatment and the other three were used as control (so treatment and control animals are not paired). From each of ...
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61 views

Fractional Factorial Design with Highest Resolution

In the book Design and Analysis of Experiments by Douglas C. Montgomery , it is written that We usually like to employ fractional designs that have the highest ...
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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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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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33 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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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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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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32 views

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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283 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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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. ...