Why teach with technology? A healthy skepticism is appropriate when it comes to new educational tools.   The general perception of technology by people outside the educational field may be glowing and hopeful, but teachers are often more cautious: "In sum, technology offers the teacher a vague promise of increased effectiveness at the price of having to know and do more" -- Kenneth E. Eble, The Craft of Teaching (122). 

convenience and availability capacity of support infrastructures tradition (slide projectors are common in Art History departments, less so in others) expense students' level of skill and comfort (although they can learn) instructor's level of skill and comfort (although they can learn, too) required preparation time technical requirements (darkened room?  Internet connection?) capacity to handle certain types of information, such as images, sound, or long passages of text influence on classroom dynamics (does it encourage students to talk to each other?)