Table 1.

Effect of Number of Acquisition Trials, CS, and US Strength

Exp. no.	CS	US	Conditioning trials	Retention tests							N	Comments
				% PER acquisition		Early LTM % PER		Late LTM % PER		Test groups
				massed	spaced	massed	spaced	massed	spaced
1	carnation	1.25 m	5	48%	81%	36%	72%	29%	86%	same	62
2	propionic acid	1.25 m	5	73%	86%	50%	81%	35%	81%	same	99
3	propionic acid	1.25 m	5	23%	45%	20%	50%	11%	52%	same	77
4	propionic acid	1.25 m	5	62%	90%	48%	90%	45%	96%	same	58
5	propionic acid	1.25 m	5	60%	64%	20%	79%	10%	86%	same	24
6	hexanol	1.25 m	5	54%	79%	46%	87%	44%	82%	same	121
7	hexanol	0.5 m	5	59%	71%	59%	79%	59%	88%	same	58
8	hexanol	2.5 m	5	59%	93%	50%	78%	56%	100%	same	59
9	carnation	1.25 m	5	72%	97%	48%	81%	—	—	different	60	only early
												LTM tested
10	carnation	1.25 m	5	7%	64%	—	—	29%	68%	different	39	only late
												LTM tested
11	propionic acid	1.25 m	8	29%	70%	19%	43%	—	—	different	59
				25%	100%	—	—	39%	86%
12	hexanol	1.25 m	12	21%	52%	—	—	46%	65%	different	51	only late
												LTM tested
13	mechanical	1.25 m	8	53%	75%	53%	56%	—	—	different	59
	stimulus			63%	83%	—	—	31%	75%
14	infrared	1.25 m	8	47%	59%	43%	50%	—	—	different	89
	stimulus			51%	57%	—	—	30%	60%