Author Archive
Why the CBCL’s Inter-rater Reliability is poor at the Item and Syndrome level
There seem to be no obvious methodological or statistical issues that could account for the poor inter-rater reliability. Embregts argues that informants might have a different view on presence and severity of behavioral problems depending on the frequency and quality of interaction they have with the client (“biased” data). Secondly both judges might have different standards of judgment when interpreting the behavioral data (“biased” interpretation). Another reason for poor inter-rater reliability might be different characteristics of the judges. As Albert Einstein already noted, we can not observe a process without influencing it – that notion is valid on a molecular level and (even more so – in my opinion) on a behavioral level. Different behaviors by the judge might lead the client to act differently. Ultimately data collection would be biased if the behaviour of the judge leads to behavior that would not be observed in a “normal situation”. This is a limitation we have to live with when conduction non-experimental studies. Diagnostic overshadowing is another process that could influence assessment of psychopathology and related behaviours: Judges might be inclined to attribute overlap between symptoms of mental retardation and psychopathology to the mental retardation. Finally the author hypothesis that low level of intellectual functioning make it hard for the judge to project oneself in the clients mental level. It might also be that there is just not one perfect treatment and many roads lead to Rome so to speak. If it is found that different treatment are effective and that they have about the same effect, inter-rater reliability should be computed in relation to treatment families and not single specific treatments, otherwise the IR rating might be much too conservative.
Heterotypic Continuity & Comorbidity
Heterotypical continuity means that an underlying (developmental) process or impairment stays the same, but the manifestations do not stay the same. For example a child with autism might first show impairments of non-verbal skills and problems in eye-contact. In a later developmental stage the manifestations would be different, such as stereotypical behaviour or language problems.
In psychopathological progression one disorder can be seen as a risk factor for developing another disorder. For example eating disorders such as anorexia nervosa have a influence on neurotransmitter levels such as serotonin. Imbalance of that neurotransmitter is related to general anxiety disorder and depression. In that way eating disorder do not cause depression, but it certainly puts the individual at a higher risk.
Whereas comorbidity is a correlational construct, the concepts of heterotypic continuity and psychopathological progression are causal theories in a developmental framework, that take the development of the individual into account. One could argue that, where comorbidity uses data to state a fact, the other two concepts actually try to explain the process.
Homeotypic continuity can be seen as the opposite of heterotypic continuity. Whereas in heterotypic continuity the process stays the same and the manifestations change, in homeotypic continuity the manifestations stay the same, but the underlying process changes. For example a child might resort to aggression, because it lacks the necessary skills to make contact with peers at schools. Later in life aggression against peers might be mainly attributed to an antisocial personal disorder.
Behavioural Science Blog 