7. Control Techniques Flashcards
method of difference
if groups are equivalent on every variable except for one, then that one variable is the cause of the difference between the groups
differential influence
when the influence of an extraneous variable is different for the various groups
randomization
control technique that equates groups of participants by ensuring every member has an equal chance of being assigned to any group
random assignment
randomly assigning a sample of individuals to a specific number of comparison groups
matching
using any variety of techniques for equating participants on one or more variables. (ie. same number of men/women in each group, etc)
matching variable
the extraneous variable used in matching
statistical control
control of measured extraneous variables during data analysis (rather than matching based on a variable, allow it to vary in its natural units and then consider the variable during statistical analysis)
yoked control
a matching technique that matches participants on the basis of the temporal sequence of administering an event (ie. controls for the possible influence of participant controlled events. each control participant is yoked to an experimental participant. when the experimental subject engages in a behavior, the yoked subject is given the same outcome)
precision control
a matching technique in which each participant ins matched with another participant on selected variables
frequency distribution control
a matching technique that matches groups of participants by equating the overall distribution of the chosen variables
counterbalancing
a technique used to control for sequencing effects
order effect
a sequencing effect arising from the order in which the treatment conditions are administered to participants. (ie. familiarity with format of test may increase performance on second test)
carryover effect
a sequencing effect that occurs when performance in one treatment condition affects performance in another treatment condition. This can be counterbalanced by “wash out” periods. (ie. different therapy types may result in different immediate after affects that carry over to subsequent treatment sessions)
randomized counterbalancing
sequence order is randomly determined for each individual
intrasubject counterbalancing
administering the treatment conditions to each individual participant in more than one order (ie. the Ss takes all the treatment conditions, more than one time, in each order. For example, for a taste test, they might taste pepsi first, then coke, and then coke, and then pepsi. This controls for sequence effects)
