The output of task analysis is some breakdown of the tasks people perform and, depending on the techniques chosen, the things that are employed and the plans and sequences of actions used to perform the tasks. The way this information is utilized depends very much on the use to which it is put. | Models of the System Lecture 25 By Prof. Dr. Sajjad Mohsin Today’s Outline Today we will learn about, Formal Models, definitions notations and classes. Issues of notations Naïve Psychology Intoduction Standard formalisms Software engineering notations used to specify the required behaviour of specific interactive systems Interaction models Special purpose mathematical models of interactive systems, used to describe usability properties at a generic level Status/event analysis An example of an engineering level method drawing on both formal modelling and naive psychology types of system model dialogue – main modes full state definition abstract interaction model specific system generic issues Relationship with dialogue Dialogue modelling is linked to semantics. System semantics affects the dialogue structure But the basis is different Rather than dictate what actions are legal, these formalisms tell what each action does to the system Irony Computers are inherently mathematical machines. Humans are not. Formal techniques are well accepted for cognitive models of the user and the dialogue (what the user should do). Formal techniques are not yet well accepted for dictating what the system should do for the user! standard formalisms general computing notations to specify a particular system General computational formalisms Standard software engineering formalisms can be used to specify an interactive system. Referred to as formal methods Model based describe system states and operations . Z, VDM The two major model-oriented specification notations in use today are Z and VDM. The Vienna Development Method (VDM) is one of the longest-established formal methods for the development of computer-based systems. Originating in work done at IBM's Vienna Laboratory in the 1970s, it has grown to include a group of techniques and tools based on a formal specification language - the VDM Specification Language (VDM-SL). The Z notation is a formal . | Models of the System Lecture 25 By Prof. Dr. Sajjad Mohsin Today’s Outline Today we will learn about, Formal Models, definitions notations and classes. Issues of notations Naïve Psychology Intoduction Standard formalisms Software engineering notations used to specify the required behaviour of specific interactive systems Interaction models Special purpose mathematical models of interactive systems, used to describe usability properties at a generic level Status/event analysis An example of an engineering level method drawing on both formal modelling and naive psychology types of system model dialogue – main modes full state definition abstract interaction model specific system generic issues Relationship with dialogue Dialogue modelling is linked to semantics. System semantics affects the dialogue structure But the basis is different Rather than dictate what actions are legal, these formalisms tell what each action does to the system Irony Computers are inherently .
