Telegraphy the sense of a system that can transmit arbitrary messages over arbitrary distances. Lines of signalling relay stations can send messages to any required distance, but all these systems are limited to one extent or another in the range of messages that they can send. A system like flag semaphore, with an alphabetic code, can certainly send any given message, but the system is designed for short-range communication between two persons. An engine order telegraph, used to send instructions from the bridge of a ship to the engine room, fails to meet both criteria; it has a limited distance and
Alphabetic principle is also seen as a critical heuristic for learning to spell. Two contrasting philosophies exist with regard to emergent readers learning to associate letters to speech sounds in English. Proponents of phonics argue that this relationship needs to be taught explicitly and to be learned to automaticity, in order to facilitate the rapid word recognition upon which comprehension depends. Others, including advocates of whole-language who hold that reading should be taught holistically, assert that children can naturally intuit the relationship between letters and sounds. Alphabetic principle According to the alphabetic principle, letters and combinations of letters are the symbols used