Given the interdisciplinary influences on school psychology along with its requirement to comply with federal and state law in the United States, scientific progress in the area of cognitive assessment and specific learning disabilities (SLD) identification has experienced slow, if not stagnant, progress. Extrapolation of research from one discipline to that of assessment is common in school psychology where test authors and creators of interpretive and diagnostic systems make theoretical and empirical justification for their claims with correlational research and factor analysis. Although these methodologies may appear to support an underlying theory or interpretive approach, they can produce divergent results depending upon sample size and methodological choice. Consequently, greater replication and reproduction is required. Federal and state law in the United States may perpetuate low value practices among practitioners who view them as acceptable since they are legal. School psychology does not have regulatory agencies to oversee practices. All of these influences impinge on scientific progress in cognitive assessment and SLD identification. Fortunately, Canada is not beholden to omnibus special education law so its academic institutions and agencies (e.g., school districts) may be better poised to engender scientific progress in cognitive assessment and SLD identification.