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When a Placebo is not a Placebo: the value of effect size measures in assessing the validity of deception used in the balanced placebo design
Author(s) -
COLE JON A.,
BURKHART BARRY R.
Publication year - 1987
Publication title -
british journal of addiction
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.424
H-Index - 193
eISSN - 1360-0443
pISSN - 0952-0481
DOI - 10.1111/j.1360-0443.1987.tb01527.x
Subject(s) - placebo , expectancy theory , credibility , psychology , measure (data warehouse) , deception , research design , applied psychology , computer science , statistics , social psychology , medicine , mathematics , data mining , alternative medicine , pathology , political science , law
Summary Although the use of the balanced placebo design has been invaluable in untangling alcohol's pharmacological and expectancy effects, only recently has the validity of the design been evaluated. The critical importance of checking the effectiveness of the expectancy manipulation has been singled out as a key methodological issue in assessing the validity of the balanced placebo design. It has been suggested by other researchers that a variety of credibility checks be used for this purpose. In this article it is recommended that a measure of effect size, such as omega squared, be utilized for each of the credibility checks as a measure of the strength of the experimental manipulation. The value of this information is illustrated by presentation of the data from a study utilizing the balanced placebo design.