Tuesday, July 29, 2008

Implicit Web

The Implicit Web is a concept coined in 2007 to denote web sites which specialize in the synthesis of personal information gleaned from the Internet into a single, coherent picture of user behavior. Implicit data may include clickstream information, media consumption habits, location tracking or any data generated without "explicit" input from a user. Presumed advantages of implicit data include accuracy, ease of input and comprehensiveness.

The term Implicit Web was popularized by the technology investors Josh Kopelman, Fred Wilson, and Brad Feld.

Monday, July 21, 2008

Data hierarchy

Data Hierarchy refers to the systematic organization of data, often in a hierarchical form. Data organization involves fields, records, files and so on.

A data field holds a single fact. Consider a date field, e.g. "September 19, 2004". This can be treated as a single date field (eg birthdate), or 3 fields, namely, month, day of month and year.

A record is a collection of related fields. An Employee record may contain a name field(s), address fields, birthdate field and so on.

A file is a collection of related records. If there are 100 employees, then each employee would have a record (e.g. called Employee Personal Details record) and the collection of 100 such records would constitute a file (in this case, called Employee Personal Details file).

Files are integrated into a database. This is done using a Database Management System. If there are other facets of employee data that we wish to capture, then other files such as Employee Training History file and Employee Work History file could be created as well.

Monday, July 14, 2008

Relational model

The relational model for database management is a database model based on first-order predicate logic, first formulated and proposed in 1969 by Edgar Codd.

Its core idea is to describe a database as a collection of predicates over a finite set of predicate variables, describing constraints on the possible values and combinations of values. The content of the database at any given time is a finite model (logic) of the database, i.e. a set of relations, one per predicate variable, such that all predicates are satisfied. A request for information from the database (a database query) is also a predicate.

The purpose of the relational model is to provide a declarative method for specifying data and queries: we directly state what information the database contains and what information we want from it, and let the database management system software take care of describing data structures for storing the data and retrieval procedures for getting queries answered.

Tuesday, July 08, 2008

Information ecology

In the context of an evolving information society, the term information ecology was coined by various persons in the 1980s and 1990s. It marks a connection between ecological ideas with the dynamics and properties of the increasingly dense, complex and important digital informational environment and has been gaining progressively wider acceptance in a growing number of disciplines. "Information ecology" often is used as metaphor, viewing the informational space as an ecosystem.

Wednesday, July 02, 2008

Malware

Malware is software designed to infiltrate or damage a computer system without the owner's informed consent. The term is a portmanteau of the words malicious and software. The expression is a general term used by computer professionals to mean a variety of forms of hostile, intrusive, or annoying software or program code.

Many normal computer users are however still unfamiliar with the term, and most never use it. Instead, "computer virus" is incorrectly used in common parlance and even in the media to describe all kinds of malware, though not all malware are viruses.

Software is considered malware based on the perceived intent of the creator rather than any particular features. Malware includes computer viruses, worms, trojan horses, most rootkits, spyware, dishonest adware, and other malicious and unwanted software. In law, malware is sometimes known as a computer contaminant, for instance in the legal codes of California, West Virginia, and several other American states.