Dataset beerhead_halflife.dat Source: J.R. Hudson (1968). "Institute of Brewing: Analysis Committee Measurement of Head-Retention in Bottled Beer," Journal of the Institute of Brewing, Vol. 74, Issue 3, pp. 275-285. Description: Beer head half lifes for 5 beer brands, 5 laboratories, 2 types of carborundum (distributed by maker, purchased in market), with 4 replicates per combination. Variables/Columns Laboratory 8 Carborundum 16 /* 1=Distributed, 2=Purchased */ Beer 24 Foam half-life (seconds) 28-32