1 2 TH E M I N D OF TH E BUY E R
m etho d o f psych ol ogy a nd sh ow th a t i t i s
i dentical wi th tha t employe d by oth e r sciences.
S cientific metho d—ex periment. In desc ri b
ing an d expl aining th e ac ti on s. of th e b uyer,
p sych ol o gy empl oys th e m e th o d c ommon to
al l science s—e xperim ent. Th e p ro c e dure of
a n exp eri m en t m ay b e de sc ribed a s follows(^1). To o bser ve th e ph enom enon un der c on
sidera tion. To obse rve systema tically, n o t
spa sm odi cally o r sp ora dically. Inde ed, to be
th oroughly scien tific w e m us t m ake o ur o b
serva tio ns under ca refully c on trolle d c ondi
ti ons— usually in th e l aborat ory wh e re w e ca n
c on trol th em more easily th an i n th e h urly
burly o f eve ryday life. B y “ c on t rol” w e m ea n
to a rrange c onditions so th a t we m ay rep eat
o ur ob ser va tion s ( for i n maki ng scien tific
m easurem ent s w e c an no t rely up on m erely
o ne observa ti on ) watch o ne fac tor a t a time ;
an d ch ange c ondi tions a t will. In brief, a n
e xp e ri men t i s “ a serie s o f obse rvations which
c a n b e rep ea te d, isol a te d an d va ried. ”
(^2). W e must r eco rd o ur mea sure s. W e
m ust use grea t ca re i n d oing thi s ; desc ri bing
exactl y th e c ondi ti ons un de r which we p er
form o ur expe rimen t, so th a t a noth e r ex peri
m ent er w orking un de r the sa m e c onditi ons
may sec ure simila r resul t s. W e rec o rd our