6.3.1.1 Information need
Information need is one major criterion that divides searching and browsing as retrieval methods. For a specific and know information need, searching appears the suitable choice as it would help the user obtain the “needle” from the “haystack” efficiently. In comparison, browsing can be used to perform retrieval tasks foe users with broad and unspecified information needs. People can use different browsing tactics (e.g., scanning and navigation) to find out if there in any information relevant to the information need in the IR system.