8
Bolstad, 1973). Specifically, factors such as the complexity of the coding system (Hops, Davis, & Longoria, 1995; Jones, Reid, & Patterson, 1974; Kazdin, 1977; Mash & McElwee, 1974), the frequency of occurrence of behaviors (Hartmann, 1977), observer expectancies (Kazdin, 1977), observer drift (Johnson & Bolstad, 1973), and subject reactivity (Johnson & Boldstad, 1973) all have an impact on the interpretability of observational data. Behavioral observation coding systems need to incorporate and account for these influences.
Standardization
In addition to being reliable and valid, observational systems must be adequately standardized (Ciminero & Drabman, 1987; Goldfried, 1979). The absence of normative data has been a problem for direct observation systems, particularly as their use has increased (Ciminero & Drabman, 1987). Without normative data, one cannot assess the degree to which a parent's or child's behavior is outside of normal limits nor does one have a criterion to evaluate treatment effectiveness (Robinson & Eyberg, 1981). Practicality
Concerns regarding the practicality of direct observation, particularly in clinical
settings, have been raised (Mash & Terdal, 1988). While direct observation in naturalistic settings, such as the home or school, is thought to be too time consuming for typical clinical applications, observation in analogue situations is thought to yield information about behavior that may not be generalizable to more relevant settings. Structured behavioral observations in the laboratory setting have been proposed as an effective alternative because they can efficiently elicit the target behaviors and can facilitate