Donald Norman's Model of Interaction, often referred to as the "Seven Stages of Action" or the "Seven Stages of a User's Cognitive Activity," provides a detailed framework for understanding the cognitive and physical steps a user takes when interacting with a system. It serves as a diagnostic tool for designers, helping to pinpoint where potential difficulties or "gulfs" in the interaction might occur. The model emphasizes the iterative nature of user action and evaluation.

This phase details the user's progression from an abstract goal to concrete physical actions on the interface.

1. Forming the Goal: This is the highest level of abstraction. The user establishes a desired state or outcome they wish to achieve (e.g., "I want to reserve a train ticket to Delhi," "I need to find a specific document"). This stage is purely internal to the user.
2. Forming the Intention: The user translates the abstract goal into a more concrete plan that they believe the system can facilitate. This involves choosing a specific method or strategy within the system's perceived capabilities (e.g., "To reserve a ticket, I'll use the 'Book Tickets' feature on the website"). This is where the user starts to map their goal onto the system's perceived functionalities.
3. Specifying the Action Sequence: The user breaks down their intention into a sequence of specific physical or digital actions required by the interface. This involves deciding which controls to manipulate and in what order (e.g., "Click on 'Trains', then enter 'Delhi' in the destination field, then click 'Search'"). This step requires knowledge of the system's interface elements and their functions.
4. Executing the Action: The user physically performs the determined actions on the interface. This involves motor movements like clicking a mouse, typing on a keyboard, or tapping a touchscreen (e.g., actually typing "Delhi" and clicking the search button).

This is the critical chasm between the user's intentions and the actual actions or operations allowed by the system. If the system's interface does not clearly present the available options, if its functionalities are hidden, or if the means of interaction are unclear or poorly mapped, the user will struggle to form the correct intention or to specify and execute the required actions. The user asks: "What do I do?" or "How do I do it?" A large gulf here indicates poor discoverability, ambiguous affordances, or non-intuitive mapping.

This phase describes how the user interprets the system's response to their actions and assesses whether their goal has been achieved.

1. Perceiving the System State: The user observes the changes in the system after their action. This involves attending to visual, auditory, or haptic feedback provided by the interface (e.g., "The screen changed; there's a list of train options now," "I heard a confirmation sound"). This is about sensing what the system is presenting.
2. Interpreting the System State: The user processes the perceived information and assigns meaning to it. They try to understand what the system's feedback signifies in the context of their task (e.g., "This list of trains means my search was successful and these are the available options"). This step involves connecting the feedback to their previous actions and the system's conceptual model.
3. Comparing the System State to the Original Goal: The user evaluates whether the current state of the system aligns with their initial goal. They assess if their objective is being met or if further actions are needed (e.g., "Yes, this is a list of trains to Delhi, so I'm on track to book my ticket"). This involves comparing the outcome to their mental model and expectations.

This is the significant gap between the system's physical representation of its state and the user's ability to interpret that state in terms of their goals and intentions. If the system's feedback is unclear, ambiguous, inconsistent, or if the resulting state is difficult to understand in relation to their initial objective, the user will struggle to determine what has happened or what to do next. The user asks: "What happened?" or "Is this what I wanted?" A large gulf here indicates poor feedback mechanisms, a confusing conceptual model, or inadequate signifiers.

Norman's model provides a powerful analytical lens for design:

● Bridging the Gulf of Execution requires designing an interface that makes it easy for users to transform their intentions into actions. This means ensuring high discoverability of functions, clear affordances, explicit signifiers, and intuitive mapping between controls and their effects. The user should effortlessly know what they can do and how to do it.

● Bridging the Gulf of Evaluation requires designing an interface that makes it easy for users to perceive and interpret the system's state in relation to their goals. This necessitates providing clear, immediate, and unambiguous feedback, supporting a consistent conceptual model, and using effective signifiers to communicate system changes. The user should easily understand what happened and where they stand relative to their objective.