What Criteria Makes Technology Educationally Useful?

These days, technology is most often educationally useful... and if not, there is probably a means to make it so!

However, I grapple with how useful certain technologies are for students in my arena of experience: the Early Childhood Classroom. 

I concluded that digital media authoring is not educationally appropriate for 4 year olds, and I jumped into a ficticious scenario for students a few years older than I am used to teaching.  I estimated that by the First Grade, students working in groups could benefit from researching a curriculum page about Dental Health and creating a simple Prezi to share with the class.

Please view the type of digital presentation I expect from my [fictitious] First Graders: 

Teacher-Created Digital Story Example

Are my expectations for First Graders to work together and author a digital presentation realistic?

Would this be educationally useful--and further--beneficial for students in the First gGrade?

Any other tips / feedback?

Thank you!