Navigational Blocks Analysis

I used the two frameworks introduced in papers "Reality Based Interaction" and "TAC Paradigm" to analyze the "Navigational Blocks" TUI.

TAC Paradigm Analysis

The Navigational Blocks TUI is structured mainly based on the Token and Constraint (TAC) paradigm with elements of the Constructive Assemblies category. It consists of four wooden blocks, which play as both token and constraint, an active space-the permanent constraint platform, and the computer screen that displays the feedback to the query created by the two previous tools. The six sides of each wooden block is coupled with a topic and five related subtopics to represent the variables and information in the digital database.

The user, either by simply specifying a variable with a single block or by attaching two blocks and creating an "and" relationship between two variables, sends a query to be retrieved from the computer. In both cases, the TUI functions as a tangible query interface where the user manipulates the block(s) to control the feedback.

However, the two instances also show a difference. In the first case, the block performs as a token and the active space functions as the only constraint. In response to the block's variable, the display screen retrieves feedback. In the second case, computational building takes place. By presenting two blocks or two variables on the active space, the blocks become each others' constraint. This relationship is recognized through a haptic response: the blocks attach magnetically and build together if the query exists. If the two variables don't construct a valid query, they repel each other. Depending on user manipulation, the TUI can function as a tangible query interface with the structure of a typical TAC paradigm or a Constructive Assembly.

RBI Analysis

The Navigational Blocks TUI clearly embodies the concept of a Reality-Based Interaction (RBI) by eradicating the use of virtual icons and menus and creating a tangible search engine to navigate through digital information. The virtual world can be manipulated with physical tools and more direct user approach through this device. In attempting to bring together the virtual world and the physical world, certain themes of reality are emphasized and others are repressed.

The manipulation of the Navigational Blocks TUI emphasizes different kinds of human skills, especially that of environmental awareness. The user needs to be familiar with the function of a block object from picking it up to rotating and positioning it to the active space. Also, the development of the "self" is required, as the Block variable facing the user, not touching the active space, is to be read by the TUI.

The Blocks also ask for a learned understanding of naive physics and multiple behaviors. Once a Block has been placed on the active space, it can be coupled with another Block's variable depending on their relationship. For example, the "women" variable can be coupled with "early 18th century" variable to create a new variable representing the "women of early 18th century." This relationship is recognized based on the physics of magnetic attraction or repulsion between the Blocks. Once the relationship is established, the Blocks can mimic the function of a computer mouse and be slid back and forth to access the requested feedback.

This magnetic relationship is designed for novice users where reality is emphasized over efficiency and users need to discover the preexisting relationship through a trial-and-error process. However, some complex involvement is helpful to eliminate unnecessary trials. The users are asked to read and differentiate the "topic" from the"subtopics" presented in each block and make educated guesses to set up different queries. This function limits accessibility to people who can read and also recognize patterns.

The expressive power and versatility is subdued for the sake of simplicity as the display screen is limited to one query and one feedback at a time.This system also lacks continuous interaction as screen information is static until the user performs another action.

The Navigational Blocks TUI balances themes of reality and advanced functionality to create a search tool that is simple enough to approach but also complex enough to experiment with.