Abstract
IMPELS is an Individualised Mathematics Planning and Evaluation of Learning Tool for
Students with Intellectual Disability. IMPELS was evaluated against 3 number sense tools
and subjected to standard validity and reliability assessments. Results obtained indicated
that IMPELS correlated strongly with the tools, ranging from 0.70 to 0.91 and 0.45 to 0.70
for Pearson and Spearman’s Rho correlation coefficients respectively. Cronbach’s alpha
and Spilt-Half Reliability (KR-20) was 0.96. IMPELS is useful for the collection of
baseline data to inform the development of individual education plans (IEPs) and for
monitoring the progress of learning of individual students.