- Pictogram: a drawing that resembles the physical object that it represents, eg. a happy face or a human
- Ideogram: a conceptual picture of an abstract idea, like the symbol of peace
- Rebus theory: sound + sound = new meaning
- Proto language: instead of letters using icons
- bits and dashes to compose letters
- send through electric impulses
- uses the binary combinations like the flag system
- the most used letters were the easier to type
- Symbol rate (n): how many symbols transferred per second eg. a bitrate. Also known as Baud.
- Difference (s): how many differences per symbol, eg. a bit would be two differences per symbol.
- the symbol rate would dictate the depth of the decision tree
- Message space: the width of the base of the decision tree or . In other words, how many different symbols or letters can be sent in a specific amount of time.
Measure amount of information transmitted in a unit of time by