, Week 3
RECALL
Why do we block?
To take into another
account source ofvariation
once we control for blocking, we reduce res. error
i.e Msres t
... * *
-> if f*increases enough, we could F*<
get Far, at
i.e we could end up rej Ho, before we accepted
NOTE:Even if
we conclude thatthere is no sig difference between
nu
blocks, itcould still be useful to include the blocking var because
itwill reduce the res error thus change the conclusion
EXAMPLE:
I IIIIIII I
Bi
is
F ↑6
Pi 19.4 106.4
24.8
P2 32.6 19.4 21.1 14.4 19.4 131.6
P3 2727.9
"
9.1 20.5
PLI 32.7 25.2 11.9 18.8
P5 33 24.3 15.8 18.6 14.2 20.8 176.7
Ti
-
144.1 119.973.299.666.393-5
:treatment Fertiliser
=
... Blocking var= plois
RECALL
Why do we block?
To take into another
account source ofvariation
once we control for blocking, we reduce res. error
i.e Msres t
... * *
-> if f*increases enough, we could F*<
get Far, at
i.e we could end up rej Ho, before we accepted
NOTE:Even if
we conclude thatthere is no sig difference between
nu
blocks, itcould still be useful to include the blocking var because
itwill reduce the res error thus change the conclusion
EXAMPLE:
I IIIIIII I
Bi
is
F ↑6
Pi 19.4 106.4
24.8
P2 32.6 19.4 21.1 14.4 19.4 131.6
P3 2727.9
"
9.1 20.5
PLI 32.7 25.2 11.9 18.8
P5 33 24.3 15.8 18.6 14.2 20.8 176.7
Ti
-
144.1 119.973.299.666.393-5
:treatment Fertiliser
=
... Blocking var= plois
