03.07.2013 Views

Nested Designs - Scholar

Nested Designs - Scholar

Nested Designs - Scholar

SHOW MORE
SHOW LESS

You also want an ePaper? Increase the reach of your titles

YUMPU automatically turns print PDFs into web optimized ePapers that Google loves.

differs from the mean transpiration rate i of hybrid i. But we are not interested in the 15<br />

effects (2) of these 15 randomly selected pots specifically, because they are 15 of a huge<br />

population of pots that we could have used and in which we are equally interested Indeed,<br />

we are not interest in any of the pots specifically. And the same is true for the random<br />

plants within the pots, and random leaves within the plants and pots. Rather we are<br />

interested in the distribution of the random effects and random means, because the<br />

distribution describes the entire populations, and the distributions of the random effects<br />

affect transpiration rates.<br />

The random effects of each random factor are assumed to have<br />

o (central location) mean = 0, thus,<br />

<br />

<br />

E B E C E e<br />

0<br />

j i k i, j l i, j, k<br />

o (dispersion) variance homogeneous over levels, thus<br />

ji <br />

ki , j<br />

<br />

li , j, k <br />

2<br />

Var B for all ,<br />

B i j<br />

2<br />

Var C for all , ,<br />

o (shape) normal distribution, thus<br />

C i j k<br />

2<br />

Var e for all , , ,<br />

e i j k l<br />

Bji<br />

<br />

2<br />

Normal 0, B <br />

ki , j<br />

2<br />

Normal 0, C <br />

, , <br />

2<br />

Normal 0, e <br />

C<br />

e<br />

l i j k<br />

This implies that the responses Y ijkl have the following distribution<br />

o (central location)<br />

<br />

EY <br />

ijkl i<br />

nested01.docx 6 4/5/2012

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!