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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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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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59 views

Identifying method by equation (Related to Factorial Fractional Design)

I'd like to know the name of the method in the picture below. It's the same category as full - and factorial fractional design. It's quite difficult to search the net for this equation - I've tried ...
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138 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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How to test for a synergistic effect of A & B with proportions of treatment effects, if I don't have the full 2x2 table?

I currently have a 2x2 table of proportions for treatment effects that looks like: \begin{array}{lll} & \text{Treatment } A & \text{Without Treatment } A \\ \text{...
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58 views

Augmenting experiment design matrices

Consider a set of users (rows) where we are already testing several treatments (columns): $$\begin{pmatrix} E & U & E \\ U & E &E \\ \vdots & \vdots &\vdots \\ E & E &...
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112 views

Structural Equation Model - Construct Operationalization

I'm building a Structural Equation Model and I'm trying to operationalize my Dependent Variable, the construct of "Investor Behaviour" (= whether or not an investor is willing to invest in a startup). ...
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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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40 views

How to find the levels (+ or -) using the words in a Fractional Factorial?

I'm stuck on this question and would appreciate any help! Q: Given the partial defining relation I = -ABD = -ACE = BCF for a $2^{6-3}$ fractional factorial design, obtain the complete defining ...
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223 views

Explain fractional factorial design in plain English

I want to begin learning about factorial experiments and, specially, fractional factorial design. What would be a simple, plain English explanation, to get the big picture of this topic? Besides, an ...
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966 views

Some questions about AlgDesign for Fractional Factorial Design in R

I have a few Design of Experiment type questions about the AlgDesign package in R that I can't find answered online: Will using the center=TRUE option in the gen....
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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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1answer
163 views

Fractional Factorial Design

In a $2^5$ design, it is believed that only the main effects $(A,B,C,D, E)$ and $AB,AC$ interaction effects are non-zero. I need to construct a fractional factorial with minimum number of runs which ...
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684 views

$2^{5-2}$ Design : Alias Structure

$2^{5-2}$ Design Design Generators: $D=AB\quad E=AC$ Defining Relation: $I=ABD=ACE=BCDE$ $$\text{Aliases}$$ $$A=BD=CE=ABDE$$ $$B=AD=ABCE=CDE$$ $$C=ABCD=AE=BDE$$ $$D=AB=ACDE=BCE$$ $$E=ABDE=AC=BCD$$...
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Controled Factorial Experiment Design: which name or resource?

I'm designing an experiment which has to factors (A,B) with respectively 4 and 5 levels. Since this is quite a large amount, I figured I use a factorial design. However, it is unclear whether the ...
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1answer
125 views

What is the meaning of $A(B^2)$ interaction in a 3 level factorial with 2 factors $A$ and $B$, when the factors are qualitative?

I understand that when the factor is quantitative the $AB$ interaction can have a linear component and a quadratic component and so $AB^2$ makes sense there. But when we have qualitative elements how ...
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Alias Structure of one-fourth replicate of a $4^2$-Factorial Design with interaction $\text{A}{B}^3$ confounded

For finding the Alias of main effect A , i started as the following : $\text{A}$$\times$ $\text{A}{B}^3$$=\text{A}^2\text{B}^3={(\text{A}^2\text{B}^3})^2=\text{A}^4\text{B}^6=\text{B}^2$(mod $4$)$={(\...
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164 views

Fractional factorial design. only main effects considered

I have 15 factors which I want to optimize. Instead of running a fractional factorial design consisting of 32 runs, if I run a design consisting of 16 runs, will I only get main effects or any second ...
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1answer
112 views

Constructing one-ninth fraction of the $3^{5}$ design

I want to construct a $3^{5-2}$ design with $I=ABC$ and $I=CDE$ as generators. The complete defining relation for this design is: $I=ABC=CDE=ABC^{2}DE=ABD^{2}E^{2}$. This is a resolution III design ...
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2k views

Full and fractional factorial designs

I have a data set consisting of six independent environmental variables (all binomial: present / absent) and one dependent variable (binomial: disease present / absent). In order to determine the ...
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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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2k views

Are crossed factorial design and full factorial design the same concept?

About crossed factorial design, two factors A and B are crossed, if every level of A can occur in every level of B. A full factorial/crossed experiment is an experiment whose experimental units take ...