Computer Evidence Glossary

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T1: A high speed, high bandwidth leased line connection to the Internet. T1 connections deliver information at 1.544 megabits per second.

T3: A high speed, high bandwidth leased line connection to the Internet. T3 connections deliver information at 44.746 megabits per second.

Tape Drive: A hardware device used to store or backup ESI on a magnetic tape. Tape drives are usually used to back up large quantities of ESI due to their large capacity and cheap cost relative to other storage options.

Taxonomy: The science of categorization, or classification, of things based on a predetermined system. In reference to Web sites and portals, a site’s taxonomy is the way it organizes its ESI into categories and subcategories, sometimes displayed in a site map. Used in information retrieval to find documents that are related to a query by identifying other documents in the same category.

TCP/IP (Transmission Control Protocol/Internet Protocol): The first two networking protocols defined; enable the transfer of data upon which the basic workings of the features of the Internet operate. See Port.

Telnet (Telecommunications Network): A protocol for logging onto remote computers from anywhere on the Internet.

Telephony: Converting sounds into electronic signals for transmission.

Templates, Document: Sets of index fields for documents, providing framework for preparation.

Temporary (“Temp”) File: Files stored on a computer for temporary use only, often created by Internet browsers. These temp files store information about Web sites that a user has visited, and allow for more rapid display of the Web page when the user revisits the site. Forensic techniques can be used to track the history of a computer’s Internet usage through the examination of these files. Temp files are also created by common office applications, such as word process or spreadsheet applications.

Terabyte: 1,099,511,627,776 bytes ­10244 (a trillion bytes). See Byte.

Text Mining: The application of data mining (knowledge discovery in databases) to unstructured textual data. Text mining usually involves structuring the input text (often parsing, along with application of some derived linguistic features and removal of others, and ultimate insertion into a database), deriving patterns within the data, and evaluating and interpreting the output, providing such ranking results as relevance, novelty, and interestingness. Also referred to as “Text Data Mining.” See Data Mining.

TGA: Targa format. This is a “scanned format” – widely used for color­scanned materials (24­bit) as well as by various “paint” and desktop publishing packages.

Thin Client: A networked user computer that acts only as a terminal and stores no applications or user files. May have little or no hard drive space. See Client.

Thread: A series of communications, usually on a particular topic. Threads can be a series of bulletin board messages (for example, when someone posts a question and others reply with answers or additional queries on the same topic). A thread can also apply to emails or chats, where multiple conversation threads may exist simultaneously. See Email String.

Thumb Drive: See Key Drive.

Thumbnail: A miniature representation of a page or item for quick overviews to provide a general idea of the structure, content and appearance of a document. A thumbnail program may be a standalone or part of a desktop publishing or graphics program. Thumbnails provide a convenient way to browse through multiple images before retrieving the one needed. Programs often allow clicking on the thumbnail to retrieve it.

TIFF (Tagged Image File Format): A widely used and supported graphic file formats for storing bit­mapped images, with many different compression formats and resolutions. File name has .TIF extension. Can be black and white, gray­scaled, or color. Images are stored in tagged fields, and programs use the tags to accept or ignore fields, depending on the application. The format originated in the early 1980s.

TIFF Group III (compression): A one­dimensional compression format for storing black and white images that is utilized by many fax machines. See TIFF.

TIFF Group IV (compression): A two­dimensional compression format for storing black and white images. Typically compresses at a 20­to­1 ratio for standard business documents. See TIFF.

Time Zone Normalization: See Nomalization.

Toggle: A switch that is either on or off, and reverses to the opposite when selected.

Tone Arm: A device in a computer that reads to/from a hard drive.

Tool Kit Without An Interesting Name (TWAIN): A universal toolkit with standard hardware/software drivers for multi­media peripheral devices.

Toolbar: The row of graphical or text buttons that perform special functions quickly and easily.

Topology: The geometric arrangement of a computer system. Common topologies include a bus (network topology in which nodes are connected to a single cable with terminators at each end), star (local area network designed in the shape of a star, where all end points are connected to one central switching device, or hub), and ring (network topology in which nodes are connected in a closed loop; no terminators are required because there are no unconnected ends). Star networks are easier to manage than ring topology.

Track: Each of the series of concentric rings contained on a hard drive platter.

TREC (Text Retrieval Conference): An on­going series of workshops co­sponsored by NIST and the U. S. Department of Defense.

Trojan: A program that does something undocumented which the programmer intended, but that the user would not approve of if known to the user. Sometimes referred to as a “Trojan horse.” See Malware.

True Resolution: The “true” optical resolution of a scanner is the number of pixels per inch (without any software enhancements).

Twiki: A “WikiWiki” ­enables simple form­based web applications without programming, and granular access control (thought it can also operate in the classic ‘no authentication’ mode). Other enhancements include configuration variables, embedded searches, server­side includes, file attachmednts, and a plug­in API that has spawned over 150 plug­ins to link into databases, create charts, sort tables, write spreadsheets, make drawings, track Extreme Programming projects, and so on.

Typeface: There are over 10,000 typefaces available for computers. The general categories are: oldstyle (faces have slanted serifs, gradual thick to thin strokes and a slanted stress ­the “O” appears slanted), modern (faces have thin, horizontal serifs, radical thick to thin strokes and a vertical street ­the “O” does not appear to slant); slab serif (faces have thick, horizontal serifs, little or no thick­to­thin in the strokes and a vertical stress ­the “O” appears vertical); sans serif (faces have no serifs), script (from elaborate handwriting styles to casual, freeform, unconnected letter forms), decorative unusual fonts (designed to be very different and attention getting).

Glossary - Courtesy of The Sedona Conference^®