Each of these activities can be analysed, using the perspective of information-processing theory, in terms of component processes. For

example, finding a number in a telephone directory can be thought of as a visual search activity in which the successive entries in the directory are compared against some internal record of the subscriber’s name. A closer specification of the task would include the preliminary narrowing down of the search activity to the relevant alphabetic section, then locating the subscriber’s name, and finally reading off the required number and perhaps memorizing it. The terminology of a more detailed analysis might refer to the ‘encoding’ of the names on a given page in terms of ‘elementary features’ , their ‘comparison’ with some ‘ internal representation’ of the ‘target’ name, the ‘decision’ as to whether or not a ‘match’ was achieved, and the ‘selection’ of the relevant ‘response’ . A similar analysis could be provided for the processes underlying the use of the subscriber’s number for whatever purpose was in mind. All of this is to use the terminology and conceptual framework of ‘ information processing’ . It is in particular to assume a model of information processing, in which successive ‘stages’ of processing are organized in a particular way.