o ch 13 = r=1, factorial
 2 level per treatment
 should block
called 2**p
n=v*1=(2**s)*(2**(p-s))=bk
 
- what if need 2**4 with 2**2 = 
  4 blocks?
where
A=bead size  S,L
B=color      B,O
C= music     N,Y
D= light     L,H

- decide to confound ABCD and ABC 
with block of DAY and TOD
- since df for block
 is b-1 = 4-1=3
 then something else is
 confounded
FIND:
(ABCD)(ABC)=
(A**2)(B**2)
   (C**2)(D)=D
all squared is 1
note: bad to 
 confound main effect
- check this D effect on 
 x-table; really no
good design for this

	0000 0001 0010 0011 0100 0101 0110 0111 1000 1001 1010 1011 1100 1101 1110 1111
BLOCK
  M-AM   x                              x                  x          x			
  M-PM                     x       x                    x                           x
  T-AM       x                              x                     x         x
  T-PM                x       x                 x                              x


- how do we get these designs?
- observe this x-table
see sum of labels (mod 2)
for all (ABCD) and for
(ABC) in each 
separate block differs
 * we know which block 
  every treatment goes
- try a 2**4 in 2**1 blocks