This is the publisher's PDF version of: Promann, M., and Zhang, T. (2015) Applying Hierarchical Task Analysis Method to Discovery Layer Evaluation. Information Technology and Libraries, 34(1), p. 77 – 105. http://dx/ This article was first published by Information Technology and Libraries under a Creative Commons Attribution (CC-BY) license. It can be viewed online at: http://dx/


While usability tests have been helpful in evaluating the success or failure of implementing discovery layers in the library context, the focus of usability tests has remained on the search interface rather than the discovery process for users. The informal site-­‐ and context specific usability tests have offered little to test the rigor of the discovery layers against the user goals, motivations and workflow they have been designed to support. This study proposes hierarchical task analysis (HTA) as an important complementary evaluation method to usability testing of discovery layers. Relevant literature is reviewed for the discovery layers and the HTA method. As no previous application of HTA to the evaluation of discovery layers was found, this paper presents the application of HTA as an expert based and workflow centered (e.g., retrieving a relevant book or a journal article) method to evaluating discovery layers. Purdue University’s Primo by Ex Libris was used to map eleven use cases as HTA charts. Nielsen’s Goal Composition theory was used as an analytical framework to evaluate the goal charts from two perspectives: a) users’ physical interactions (i.e., clicks), and b) user’s cognitive steps (i.e., decision points for what to do next). A brief comparison of HTA and usability test findings is offered as a way of conclusion.


Task Analysis, Usability, Discovery Layer

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