It is a common tool to use alphanumeric displays on CRT for documentation, search, and communication. So, it is very important to design ergonomic displays for enhancing user performance. This paper concerns with a method of quantifing the four VDT design parameters such as total density, local density, grouping and layout complexity. A case study to demonstrate the pocedure of quantifing parameters and a comparative analysis between the ready made and the newly designed displays are provided in this paper. Concludingly, ergonomic displays which were designed in accordance with the scientific procedure were much more better than the ready made exampled displays in both of processing time and error rate.