Compare methods

	Ellis Information-Seeking Behavior Model	Berrypicking Evaluation
Field	Library Information Science	Library Information Science
Family	Process / pipeline	Process / pipeline
Year of origin	1989	1989
Originator	David Ellis	Marcia J. Bates
Type	Behavioural-features model of information-seeking activities	Model and evaluative lens for evolving, non-linear online search
Seminal source	Ellis, D. (1989). A behavioural approach to information retrieval system design. Journal of Documentation, 45(3), 171-212.	Bates, M. J. (1989). The design of browsing and berrypicking techniques for the online search interface. Online Review, 13(5), 407-424.
Aliases	Ellis Model, Ellis Behavioural Features Model, Information-Seeking Features Framework, Starting-Chaining-Browsing Model	Berrypicking Model, Evolving Search Model, Bates Berrypicking, Berry-Picking Search
Related	3	3
Summary	David Ellis's model, set out in his 1989 article 'A behavioural approach to information retrieval system design,' characterizes information seeking through a set of generic behavioural features rather than a fixed sequence of stages. From grounded-theory studies of how academic researchers actually look for information, Ellis identified features such as starting, chaining, browsing, differentiating, monitoring and extracting. The crucial claim is that these are recurring activities whose detailed pattern and interrelation vary from person to person and task to task, so information seeking is better described as a flexible repertoire of behaviours than as a single ordered process. Because each feature maps onto a concrete capability, the model was explicitly framed to inform the design of information retrieval systems that support real seeking behaviour.	Marcia Bates's berrypicking model, introduced in her 1989 Online Review article 'The design of browsing and berrypicking techniques for the online search interface,' rejects the classic picture of information retrieval as a single query matched against a database to return one optimal set. Real searches, Bates argued, are evolving: the query shifts as the searcher learns, and useful information is gathered bit-at-a-time, like picking scattered berries, from many different sources using many different techniques. Used as an evaluative lens, the berrypicking model judges search systems and interfaces not by how well they answer one fixed query but by how well they support a continually changing need — letting searchers move fluidly among footnote chasing, citation searching, journal runs, area scans and subject searches as their understanding develops.