Virtual reality can be used to enhance education, especially in the remote context. Cross-reality interfaces can be useful for users who wish to access shared virtual spaces from different devices. Emotion recognition can then be used to supplement the lost non-verbal cues and allow teachers to address students in need. We introduce several types of cross-reality interface to allow teachers to present material while unencumbered by standard VR headsets. A virtual mirror streams the teacher's 3D video imagery to connected students, and visual aids assist in pointing to virtual objects of varying depths. A desktop interface with additional sensors redirects the teacher's input to animate their avatar in a more human-like manner than traditional desktop cross-reality interfaces. To further emotion recognition, we design a set of active emotion elicitation tasks fundamentally different from traditional passive stimuli and validate their ability to elicit distinct emotional responses. We then design and examine user interfaces for rating emotion in a time-continuous manner to enable finer-grained training datasets. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]