Locating SEM Information

To access the Standard Error of Measurement (SEM), refer to the technical manual of the test. Locate the appropriate SEM values categorized by age, specifically during the initial testing session.

OR Calculate SEM from Mean and SD

Enter the values below to calculate SEM:

Mean: Standard Deviation: Sample Size (N): Calculate SEM

Calculation of RCI

The Reliable Change Index (RCI) is calculated using the following formula:

    RCI = (XPost - XPre) / SEM
  

Where:

• X_Post is the post-assessment score.
• X_Pre is the pre-assessment score.
• SEM is the Standard Error of Measurement.

The result of this calculation gives an indication of whether the observed change between the pre-assessment and post-assessment scores is statistically significant. Generally, if the RCI value exceeds a certain threshold (often ±1.96 or ±1.645 for a desired level of significance), it suggests a reliable and meaningful change in the individual's scores over time.