Measurement of spiritual intelligence relies on self-reporting. David King and Teresa L. DeCicco have developed a self-report measure, the Spiritual Intelligence Self-Report Inventory (SISRI-24) with psychometric and statistical support across two large university samples.[15] Cindy Wigglesworth has developed the SQ21, a self-assessment inventory that has tested positively for criterion validity and construct validity in statistically significant samples.[17] Wigglesworth's SQ model and assessment instrument have been successfully used in corporate settings.[18]