A Comparison of Different Methods for Measuring Individual Change in Kindergarten Children

Measuring progress in students is an important consideration when making decisions in education, clinical practice, and research. However, change due to learning over time at the group level cannot be applied to interpret individual change. Therefore, the current study compared four methods for measuring individual change: reliable change index controlling for practice effects (RCI), standardized individual difference (SID), estimated standardized regression-based (SRB) change, and a normalization approach. Participants included 157 children (4 years initially and 5 years at follow-up) who completed measures of language, reading, and mathematics and were tested 1 year apart. We measured individual differences in children as they developed academic-relevant competencies. The RCI and SID indices yielded the same results. While group-based statistics did not find a change overall, the RCI/SID and SRB methods identified 7.64% and 8.28% of students as having changed, respectively. Further, in a subgroup of 54 low scorers, the RCI/SID and SRB methods indicated that 14.81% and 16.67% of students changed, respectively, whereas the normalization method identified a higher rate at 24.07%. The RCI, SID, and SRB methods showed similar results, whereas the normalization method differed from the others. Finally, a practical tool (Excel-based Growth Calculator) is provided to assist practitioners in evaluating individual change. Overall, these methods provide starting points for measuring change in individuals.