"Animals" Split Plot DOE

[#1]

Hi, in JMP Sample Data there is a small data set "Animals" for illustrating a split plot design, see attachment.

I understand that nesting subject into species generates six whole plots for estimating random error. However it is strange to see that the 4 levels of the factor Season, to my opinion a "hard to change" factor is treated as a subplot effect? How is this Animals DOE created using Custom design? I can do this when using Species and Subject both as hard to change factors and Season as easy to change? Technically this works but I have problems with the time effect "Season" easy to change..

[#2]

IY= Season + Species + Season*Species + Subject[Species] is the required interaction model. How do you specify this in Custom design? 

[#3]

I'm sorry, this may not be the answer you want, but I would not use custom design to design the sampling plan.  The customer design platform is meant to design experiments not sampling plans.

Also, I will add not all split-plots are created to handle difficult to change factors (these are just convenience split-plots.  There are other times when you want to restrict randomization to improve the precision of the design (efficiency split-plots).  I create these manually in JMP.

For more on this see 

Box, G.E.P., Stephen Jones (1992), “Split-plot designs for robust product experimentation”, Journal of Applied Statistics, Vol. 19, No. 1

[#4]

Is a DOE not meant to gather data, create a sampling plan to meet an objective? In this case assess whether there is a  difference in run difference between a fox & coyote. 

[#5]

Suppose we're also interested in the effect of age & gender of both animals & all interaction effects and that #runs is restricted, some DOE support will be a help. 

[#6]

Yes all of these components can be assessed with sampling. DOE is when you manipulate factors in an “organized” fashion. There is no manipulation in the study you suggest.

[#7]

Strange.. in the JMP DOE tutorial, this case study is an example for a split plot design?

[#8]

Which DOE tutorial do you refer to?  Could you include a link?

[#9]

Here's the link

https://www.jmp.com/support/help/en/16.1/?os=win&source=application#page/jmp/simple-split-plot-or-re...

[#10]

Also

https://www.jmp.com/support/help/en/16.1/?os=win&source=application#page/jmp/split-plot-design-examp...

[#11]

Okay this makes sense, both of those links refer to analyzing data containing split plots, not designing the experiment itself.  Split plots can show up in all sorts of places besides tables created with the custom DOE platform, and the animals data table is just such an example. To learn about designing experiments where different treatments are applied to the same experimental units I suggest setting the Animals data table aside and watching this talk by @DonMcCormack:

Split-Plot and Strip-Plot Designed Experiments