Average Co-Inventor Count = 1.60
ph-index = 2
The patent ph-index is calculated by counting the number of publications for which an author has been cited by other authors at least that same number of times.
Company Filing History:
1. Educational Testing Service (2 from 222 patents)
2 patents:
1. 5011413 - Machine-interpretable figural response testing
2. 4978305 - Free response test grading method