Black and Wiliam (1998a) also noted that for assessment to function formatively, the feedback information had to be used, and thus the differential treatments that are incorporated in response to the feedback are at the heart of effective learning.
A hypervisor is a unique type of software that allows a computer to run more than one operating system (OS). Through a process known as virtualization, the software tricks each OS into thinking it has exclusive access to a particular set of hardware.
Type II Hypervisor. This model (shown below) is also known as a hosted hypervisor. The software is not installed onto the bare-metal, but instead is loaded on top of an already live operating system. For example, a server running Windows Server 2008R2 can have VMware Workstation 8 installed on top of that OS.