ABSTRACT
"The soundest empirical test of the reliability of data is provided by replicating". This chapter describes two types of direct replications: intra-subject direct replication and inter-subject direct replication. Both intra-subject and inter-subject direct replications refer to an investigator's attempts to repeat an experimental effect with the same participant. M. Sidman discusses a variation of inter-subject replication, which he labels "inter-group" replication. As a criterion of reliability and generality, inter-subject replication is a more powerful tool than intergroup replication. Intergroup replication provides an indicator of reliability insofar as it demonstrates that changes in central tendency for a group can be repeated. With inter-subject replication each additional experiment increases the representativeness of the findings. Systematic replication was defined by M. Hersen and D. H. Barlow as "any attempt to replicate findings from a direct replication series, varying settings, behavior change agents, behavior disorders, or any combination thereof."
