Diverse Contributions to Implicit Human-Computer Interaction

Thesis cover image

A thesis submitted by Luis A. Leiva in fulfillment for the degree of Doctor of Philosophy in Computer Science from the Universitat Politècnica de València, supervised by Roberto Vivó and Enrique Vidal. This thesis received international mention, cum laude mention, and an extraordinary doctorate award.


While interacting with computer applications, we submit an important amount of information unconsciously. By studying these implicit interactions we can better understand what characteristics of user interfaces add benefit (or not), thus deriving design implications for future systems.

The main advantage of processing implicit input data from the user is that every interaction with the system can contribute to enhance its utility. Additionally, such an input removes the cost of having to interrupt the user to submit explicit information that can be little related to the purpose of using the system. On the contrary, sometimes implicit interactions do not provide clear and concrete data. As such, how this source of information is managed deserves a special attention.

This research is two-fold: 1) to apply new perspectives both to the design and the development of tools that can take advantage from user's implicit interactions, and 2) provide researchers with a series of evaluation methodologies of interactive systems that are ruled by such implicit input methods. Five scenarios are discussed to illustrate the feasibility and suitability of this thesis framework. Empirical results with real users show that tapping implicit interactions is a useful asset to enhance computer systems in a variety of ways.


The thesis is available as a single PDF file: either as a one-sided version (137 pages, 4.4 MB) or as a two-sided version for printing (148 pages, 4.4 MB). Chapters can be downloaded separately:

  1. Introduction (13 pages, 218 KB)
  2. Interactive Usability Evaluation (18 pages, 754 KB)
  3. Behavioral Clustering (24 pages, 513 KB)
  4. Human Multitasking (15 pages, 486 KB)
  5. Adaptive User Interfaces (16 pages, 607 KB)
  6. Interactive Pattern Recognition (24 pages, 399 KB)
  7. General Conclusions (3 pages, 58 KB)


  1. Appendix: Research Dissemination (4 pages, 77 KB)
  2. Frontmatter (12 pages, 953 KB)
  3. Backmatter (7 pages, 67 KB)
  4. Defense slides (3 MB)
  5. LaTeX template (56 KB) with the thesis skeleton and a makefile

BibTeX entry

  author    = {Luis A. Leiva},
  title     = {Diverse Contributions to Implicit Human-Computer Interaction},
  school    = {Universitat Politècnica de València},
  year      = {2012},
  note      = {Supervised by Roberto Vivó and Enrique Vidal},
  howpublished = {Available at \url{https://luis.leiva.name/phd/}},


Page last modified on June 19th 2016 (10:54:24).