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Great, thanks for all your answers.

Thanks again for your reply. However, I still have the feeling that I’m missing a piece of information. Why do you say, When using zero priors, there is no real need to generate multiple designs ? You advocated in your previous reply for generating multiple efficient designs for different levels of ...

Michiel,

Thanks for your reply and the reference. It’s been very useful to know how you proceed because I usually create designs with actual levels, and not levels referred to a survey instrument. In any case, I hope you don’t mind if I make a couple of more questions.

I understand your suggestion ...

Hi all,

I came across a design today in which I’d like to define the levels of some attributes as -20%,-10%, 0, +10% , and some others as 15, 35, 60 (minutes). Please, note that when I say -20%, -10%, 0, +10%, I don’t mean in reference to the value of another attribute (using .ref and .piv). What I ...

Thanks,that helped a lot.

BR.

Hi all,

This question comes from the design discussed in http://choice-metrics.com/forum/viewtopic.php?f=2&t=766 . Since the topic is different, I open a new post.

I modified my design following Michiel recomendations, and decided not to use priors since I'm not positive that they are totally ...

Great. Thanks for your time, Michiel.

Great, thanks for your insights. This conversation helped me to understand much better the issue of correlation.

I’d like to ask one last thing. Following the rationale that one can make a design based on a code scheme instead of based on the actual levels (where [-1,0,1] may mean $1, $2, $3), I ...

Thanks for your advice on points 1 and 2. Regarding 3, not that I want to insist, but the following design, with three values for the reference and high variations for the pivots, provides correlations (H index) among them of 0.98 and 0.99. Couldn’t this be really a problem?


Design
;alts = Car ...

Thanks for your response, Michiel, it’s been of great help. Nevertheless, I still have a couple considerations:

1. I understand your suggestion, but then I wonder if three separated designs (one per category) will be ‘equivalent’ to one only design that contain the 3 categories. I mean, when the ...