Week 2: Reading Notes

FOA

1.1

FOA— Finding Out About is the empirical grounding for theories referred to Information Retrieval. There’re three steps:
1. Asking a question;

Similar with QUERY— users’ information need
2. Constructing an answer;

Retrieval from the Corpus documents response to the QUERY

       3. Assessing the answer.

Relevance feedback of how relevant the answer provided, that is, how match between descriptive features mentioned by users in their queries and documents sharing those same features.

IES

1.1

What is Information Retrieval?
1. Web Search— To implement and evaluate relevance ranking algorithms under a variety of contexts and requirements on the Web search engine.

       2. Other Search Applications— A desktop search engine provides search and browsing facilities for files stored on a local hard disk and possibly on disks connected over a local network. 

Need more creation times and greater awareness of file formats.

3. Other IR Applications— Storage, manipulation and retrieval of human-language data. More about categorization and filtering.

1.2

Information Retrieval System

1. Basic Architecture

Information Need (Users)-> Translate it into Query to Search Engine-> (Search Engine) manipulates inverted index for a document collection -> (Search Engine) returns ranked lists of results (perform relevance ranking)

2. Update Documents

Update is viewed as a deletion of the old page and an addition of the new page.

3. Perform Evaluation

PRP (Probability Ranking Principle): If an IR system’s response to each query is a ranking of the documents in the collection in order of decreasing probability of relevance, then the overall effectiveness of the system to its users will be maximized.

MIR

1.1 History of Information Retrieval, adoption of Information Retrieval in the Library Science area and currently it’s at the center of the stage with other technologies.

1.2 IR Problem: to retrieve all the documents that are relevant to a user query while retrieving as few non-relevant documents as possible

1.3 High level software architecture of an IR system. Additional module: Crawling

Indexing, retrieval and ranking of documents process

1.4 History of Web and how the web changed search.