This study provides support for the use of the NCAST as a valid and reliable measure to evaluate the effectiveness of an in-home intervention on mother-child interaction.
Mother-child interaction was measured using the NCAST Teaching Scale (Sumner & Spietz, 1994), a standardized tool with acceptable internal consistency and test-retest reliability, as well as content, criterion and concurrent validity (Sumner & Spietz, 1994).
The NCAST Teaching scale is comprised of 73 binary items across four caregiver behavior subscales: sensitivity to cues (11 items), response to distress (11 items), social-emotional growth fostering (11 items), and cognitive growth fostering (17 items).
NCAST has established normative scores, as well as identified the 10th percentile cutoff that indicates the lower limit of normal for the total mother, total child and total mother-child scales.
Sumner and Spietz (1994) describe the internal consistency reliability of the NCAST, which ranges from .
A trained data collector observed the families in their homes using the NCAST Teaching Scale upon entry into and exit from the EHS program.
The NCAST and HOME assessment scales have all been standardized using white, African American, and Hispanic populations, but not the Hmong.
The Child Health Assessment Model and the Barnard Model provided the conceptual framework for this study as well as the development of the NCAST tools.
Concurrent validity of the NCAST tools has been supported by correlations with the HOME inventory.
Barnard (1994) summarized a number of studies, some of which found positive correlations when measuring preterm and term infants with both NCAST and the MDI and others found no significant or negative correlations.
Construct validity is perhaps a more useful assessment of the NCAST tools.
Importantly, the NCAST tools have been shown to identify populations at risk.