HCI Theories

The HCI Theories presented below have been utilized to evaluate the LiNC Project. A brief description of the theories presented in class is available as well as a detailed description of "Collaborative Learning Theory" by clicking on the links below. Scenario Based Design | Interface Metaphor | Direct Manipulation | Collaborative Learning Theory | Top of Page

Scenario-Based Design

Scenario-based design is an attempt to analyze and design systems and software in the context of user actions. Typical and significant user actions are explicitly detailed and documented both as a springboard for initial design concerns as well as reiterated throughout the development process. These documented user actions are referred to as scenarios and often are told as very basic, highly descriptive stories which explicitly detail user interaction with a system. Scenarios have the following characteristic elements.

Scenarios include or presuppose a setting.
Agents (actors) are the users described within the scenario.
Each agent typically has goals or objectives that are addressed in the course of the scenario. The degree of success to which the agent can accomplish, change, or create goals is a major concern of the scenario.
The scenario's plot is a highly descriptive account of the sequences of actions and events undertaken by the agent. The actions describe how the agent accomplished or changed goals within the scenario.

Scenarios place emphasis upon the user and the user's interaction with the system. These concrete descriptions make the focus of attention the activities and experiences of the user, rather than the capabilities of the system. These scenarios of use can then be analyzed to determine the applicability of the proposed system towards obtaining user goals.

A claims analysis isolates individual causal relationships between the features of the system and the consequences as experienced by the user as described within the scenario. The claims analysis provides a detailed hypothesis, or set of hypotheses, about the scenario in question. These hypotheses are ground in theory--theory relevant to the designers and developers and provide the framework for a principled requirements analysis. This requirements analysis, based in theory, highlights specific consequences illuminated in the original scenario and can be used to enhance the development process either through redesign, enhancement, or elimination of system features that negate user goals.

We have chosen three theoretical perspectives from which to base our claims analysis of the LiNC project: Interface Metaphor, Direct Manipulation, and Collaborative Learning.

Scenario Based Design | Interface Metaphor | Direct Manipulation | Collaborative Learning Theory | Top of Page

Interface Metaphor

In an attempt to capitalize on the familiarity of preexisting actions, procedures, and concepts, designers can incorporate an interface metaphor to control the complexity of an interface. Educators often use the concept of a metaphor through the use of comparisons to illuminate or illustrate more complex representations. Unfortunately, not all metaphors map perfectly or evenly to the new artifacts to which they are applied. In addition, it is typical to have composite metaphors or complementary metaphors existent within a single interface which may or may not increase understanding on the part of the user (or student).

A structural analyses addresses the representation of mappings between a metaphor's source domain and its intended target domain. The description consists of primitives and relations among these primitives in both the source and target domains. Further definitions relating to metaphors may be defined within the context of a structural analysis.

Base specificity is defined as the extent to which the structure of the metaphor source is explicitly understood. It sets an upper limit on the potential usefulness of the source domain as a predictor of the target.
Clarity refers to the precision of the node correspondences across the mapping.
Richness is the density of elements connoted in the mapping.
Abstractness refers to the level at which relations comprising the mapping are defined.
Metaphors are systematic to the extent that mapped relations are mutually constrained by membership in some structure of relations.

A pragmatic analysis of an interface metaphor considers how metaphor mappings are constrained by actual use of the system. Metaphors are often incompleteness and contain composite comparisons or mismatches. Pragmatic metaphors emphasize that interface metaphors are intentionally employed to some end, such as the common educational practice of working from "known" to "unknown" or "part" to "whole." A pragmatic analysis may capitalize on the flaws inherent in the metaphor by focusing on the the context in which the metaphors occur in use. A pragmatic analysis of an interface metaphor relies on an analysis of what users actually do, not an abstract normative analysis of what they might do.

Carroll, J.M., Mack, R.L, and Kellogg, W.A. (1988). Interface metaphors and user interface design. Handbook of human-computer interaction. Helander, M. (ed.) Elsevier Science Publishers B.V. (North-Holland). 67-85.

Scenario Based Design | Interface Metaphor | Direct Manipulation | Collaborative Learning Theory | Top of Page

Direct Manipulation

The central ideas of Direct Manipulation relate to the replacement of complex commmands with direct graphic manipulation of a system's components to provide rapid, reversible, incremental actions. The concept of Direct Manipulation implies that instead of an abstract computational medium, all the "programming" is done graphically in an attempt to address the cognitive processes of the user. The desired operation can be performed simply by manipulating the appropiate icons on the display to provide advanced functionality, possibly by connecting icons together. Connecting the icons is the equivalent of writing a program or calling on a set of statistical subroutines, but with the advantage of being able to directly manipulate and interact with the data and the connections. There are no hidden operations, syntax or commmand names to learn. The system requires expertise in the task domain but only minimal knowledge of the computer or of computing.

Direct Manipulation, as described by Shneiderman refers to systems having the following properties:

1. Continuous representation of the object of interest;

2. Physical actions of labeled button presses instead of complex syntax;

3. Rapid incremental reversible operations whose impact on the object of interest is immediately visible.

Direct Manipulation interface can be remarkably powerful. Shneiderman further suggests that systems utilizing direct manipulation have the following virtues:

1. Novices can learn basic functionality quickly, usually through a demonstration by a more experienced user;

2. Experts can work extremely rapidly to carry out a wide range of tasks, even defineing new functions and features;

3. Knowledgeable intermittent users can retain operational concepts;

4. Error messages are rarely needed;

5. Users can see immediately if their actions are futhering their goals.

Shneiderman, B. (1983). Direct manipulation: A step beyond programming languages. IEEE Computer, August, 57-69

Hutchins, E.L., Hollan, J.D., & Norman, D.A.. (1985). Direct manipulation interfaces. Human-Computer Interaction, 1, 311-338.

Scenario Based Design | Interface Metaphor | Direct Manipulation | Collaborative Learning Theory | Top of Page

Collaborative Learning Theory

Collaboration in a networked environment. Both individual and group work should be supported in a collaborative learning environment. In addition, a collaborative environment can support the division of the work required, helping each member to select the most appropriate tasks. The hardware and software must include tools for individuals to complete their own part, as well as tools for the group members to communicate with each other and to complete group goals. If designed effectively, these tools will provide privacy for individual work and provide transparency for public work.

A networked collaborative environment will support both synchronous and asynchronous communication. Synchronous communication can be used in discussions and situations that require real-time discourse. Asynchronous communication can be used in message transfers without a time requirement restriction.

Both communication styles also serve to offer support for conflict resolution and group consensus.

A networked learning environment offers unique capabilities to support various methods of expression of group members, either through text, sound, and images. Such an environment may readily support individual diversity and allow learners to capitalize on their own unique strengths.

Due to the reliance upon interaction and discourse within the on-line environment, the system should recreate the immediacy of feedback and response found in face-to-face communication. The response time of the system is restricted by both hardware and software. The interface design will either support or detract from the level of collaboration available within the system. A consistent interface is important for accurate information exchange. Each member must understand others' work in order to cooperate.

Collaborative Learning. Learning is an active, constructive process in which students integrate new material with prior knowledge to create new ideas and new meaning. Learning depends on rich contexts that ask students to collaborate with peers to identify and solve problems by engaging in higher order reasoning and problem-solving skills. Learners are diverse and have different backgrounds and experiences. Learning is a social act in which students talk to learn, and this social interaction often improves the participants understanding of the topic under consideration.

Collaborative Learning is based on the idea that learning is a naturally social act in which the participants talk among themselves; it is through talk that learning occurs. Talk relies on an immediate link with listeners and the rapid exchanges of conversation allow many things to go on at once, such as exploration, clarification, shared interpretation, insight into differences of opinion, as well as explanation by gesture and the expression of doubt. Vygotsky suggested that social change is essential to human development. As learners use language to communicate with others, their speech expresses their growing awareness and understanding of the topic being discussed and encourages cognitive development.

The Role of the Instructor. There is less direct teaching in a collaborative learning class than there is in the traditional classroom. The teacher is not seen as the fountainhead, or purveyor of knowledge that judiciously disseminates blocks of instruction. In a collaborative setting, the eacher becomes task setter, a classroom manager, and a synthesizer. Teaching in such a setting often requires helping students to decide how to attack the tasks. Teaching becomes a process of creating conditions in which collaborative learning can occur. A problem for teachers in collaborative learning is to group students so that they can teach themselves and their peers.

The Role of the Student . Students must ascertain seven shifts from their tradtional role to become successful collaborative learners.

From listener, observer, and note taker to active problem solver, contributor, and discussant.
From low or moderate expectations of preparation for class to high ones
From a private presence in the classroom with few or no risks to a public one with many risks
From attendance dictated by personal choice to attendance dictated by community expectation
From competition with peers to collaborative work with them
From responsibilities and self-direction associated with learning interdependently

Carroll, J.M., Rosson, M.B., Chin, G., & Koenemann, J. (1997) Requirements development: stages of opportunity for collaborative needs discovery. Manuscript submitted for publication.

Eales, R.T., & Byrd, L.M. (1997). Virtually deschooling society. Authentic collaborative learning via the Internet.

Gerlach, J.M. (1994). Is this collaboration? In K. Bosworth and S. Hamilton (Eds.), Collaborative Learning: Underlying Processes and Effective Techniques. (pp. 5-13). San Francisco: Jossey-Bass Publishers.

Scenario Based Design | Interface Metaphor | Direct Manipulation | Collaborative Learning Theory | Top of Page