The results of the present study can be incorporated in the
following way. Simeonsson et al (1982), proposed that although
there is empirical evidence for effectiveness of early intervention
in 48% of the studies reviewed, this is in fact an underestimation.
Effectiveness may in fact be closer to the 93% figure derived
from the conclusions of contributors to this research area.
In support of this hypothesis, the following explanations
are proposed: (1) Handicapped children made progress but statistical
significance was not obtained, given limited sample sizes.
(2) Children made progress but it occurred in domains not
measured by the dependent variables. For example, a child's
behaviour or style or response may have improved but was not
documented. Furthermore, maintenance of a certain level of
development, or prevention of regression, may also be reflective
of success but not recorded. (3) Children made no discernible
progress in developmental domains but improvement was noted
in management areas (e.g., seizure control, feeding, etc.).
(4) Children made no discernible progress but improvement
occurred in dimensions not specific to the child (e.g., family
or sibling adjustment).
In order to verify the belief that intervention is in fact
effective more frequently than the evidence suggests and to
contribute to the improvement of future accountability efforts,
two strategies for documentation are proposed. The first is
concerned with methodology and the second is conceptual in
From a methodologic point of view, systematic consideration
needs to be given to problems of comparing treatment effects.
Ethically, control groups are difficult to justify. The use
of a contrast treatment also needs to be carefully considered
in as much as it may in actuality not differ from a control
condition if the treatment is minimal, and thus raises the
same ethical problem as control groups. On the other hand,
if the contrast group is in fact a genuine alternative treatment,
generalizations based on comparisons between experimental
and contrast groups can be confounded. The lack of significant
differences between an experimental and a contrast group may
indicate that both groups improved or that neither improved
relative to the other over time. Given the nature of documentation
found in the preceding review, such distinctions would be
difficult to make. Further rnethodologic concerns include
documentation of inter-rater reliability and details pertaining
to subject variables.
The methodologic issues considered above assume that the
evaluation of effectiveness should be based on empirical evidence.
Although this is an