The capacity of a communication channel refers to the amount of information it can transmit in a given period of time. It must be able to distinguish die number of states (or the variety) it is to transmit and it must be able to do so in the time allotted. In a discrete channel such as a telegraph wire, die capacity is spoken of in terms of the "logarithm of the numbers of symbols of certain time duration... die number of such symbols handled.. the amount of information transmitted per second, using bits per second as a unit." The needed amount of channel capacity can be figured accurately for Morse code or teletype. It is more difficult to figure the needed channel capacity for an information system for management but it must be able at a minimum to handle the variety in the capacities of die reporting units. Managers are likely to need answers to questions such a s ' how can I find out what I need to know to make this decision by Wednesday?' or how much information about the new product can be handled in a press release?', or ’can we convey our plans sufficiently in a five page prospectus to secure the interest of investors so that they will undertake a full investigation?'. In these cases channel capacity refers to the limits of different formats of communication and the limits of the human beings involved to absorb oral, written and other kinds of messages. # SOURCE: Shannon,C E.,&Weaver,W.(1964).The mathematical theory of communication. Urbana: University of Illinois Press. # EXAMPLES • the number of agenda items that can be handled adequately in an hour long meeting • the amount of new information an individual can take in before the threshold of information overload is reached • the 'sound bite' in political campaigns• the number of available channels for radio and television • the neurological limits of human perception # NON-EXAMPLES • questions relating to the content of messages • whether or not the message is correctly addressed • explaining the theory of relativity on a single page or to a small child # PROBABLE ERROR • Choosing the wrong mode of communication for a message, • Choosing inappropriate transmitting conditions, • Notrealizingthatagivenformator time and presentation delimits the complexity of the message, • Not allowing for distortion of the communication due to noise. # SEE Requisite Variety; Redundancy; Information