Exercise 14

1) What is a spider? What does it do?
A spider is an automated software program used to locate and collect data from web pages for inclusion in a search engine's database, and to follow links to find new pages on the world wide web.
In the context of search engines it is an automated searching mechanism that downloads content or pages within a site for later indexing by a search engine which then indexes the text and media within websites. This indexed text and media is then cataloged and the information used to pinpoint searches based on keywords contained within the search.

2) Differentiate the various types of software agents.
- Autonomous agents Autonomous agents are software agents that claim to be autonomous, being self-contained and capable of making independent decisions, and taking actions to satisfy internal goals based upon their perceived environment.
- Distributed agents Since agents are well suited to include their required resources in their description, they can be designed to be very loosely coupled and it becomes easy to have them executed as independent threads and on distributed processors. Thus they become distributed agents and the considerations of distributed computing apply. Agent code is particularly easy to implement in a distributed fashion and should scale well
- Multi-agent systems When several agents (inter)act they may form a multi-agent system a.k.a. multiple-agent system. Characteristically such agents will not have all data or all methods available to achieve an objective (this can be referred to as "limited viewpoint") and thus will have to collaborate with other agents. Also, there may be little or no global control and thus such systems are sometimes referred to as swarm systems. As with distributed agents, data is decentralized and execution is asynchronous
- Mobile agents Agent code that moves itself, including its execution state, on to another machine, to continue execution there. This is also referred to as mobile code. Agents can be used to gather system information, taking back-up of files by copying them in client-server paradigm, monitoring network throughput or to check resources availability and moderating the resource utilization of system by checking the services running on system
- Fuzzy agents In computer science a fuzzy agent is a software agent that implements fuzzy logic. This software entity interacts with its environment through an adaptive rule-base and can therefore be considered as a type of intelligent agent.

3) Identify various activities in e-commerce where software agents are currently in use.
A common agent in use on Amazon.com is a shopping bot that provides feedback on your shopping habits when compared to other shoppers, to give you an idea of similar buying patterns.

References:
Wikipedia.(n.d.) Software agent. Retrieved 28 Oct 2009 from
http://en.wikipedia.org/wiki/Software_agent#Examples