NIFDI Technical Report 2016-2 provides full details on the calculations used in the EIC. The first two sections discuss terminology and describe the structure of the EIC. The following five sections give examples of the use of the EIC. Examples use each of the possible types of input data and different types of groups (e.g. classrooms, schools, and districts). A final section discusses ways in which the EIC could potentially help students and schools and provides cautions regarding its use. An extensive appendix explains the underlying research designs and gives the equations used in the statistical analyses. The techniques are identical to those covered in introductory college level statistics courses. While they are not complex, they are fully sufficient for answering the questions that are generally of most concern to educational consumers. Read the Tech Report