My current research area is in information visualization and human-computer interaction. I hope data visualization can enable us to better understand our complex and interesting world.

I have also worked in chemistry and medicineas summer research students when I was at the University of British Columbia and the University of Ottawa. These summer research studentships were wonderful opportunities to explore different problem domains, and to develop useful problem solving skills.

Here is a list of my publications and my services.

These are systematic reviews to snapshot current practices in visualizations.

1. Empirical Studies in Information Visualization: Seven Scenarios (2012)

   We take a new, scenario based look at evaluation in information visualization. Our seven scenarios are derived through an extensive literature review of over 800 visualization publications. These scenarios are described through their goals, the types of questions they embody and illustrated through example studies.

   Lam. H., E. Bertini, P. Isenberg, C. Plaisant, and S. Carpendale. Empirical Studies in Information Visualization: Seven Scenarios. IEEE Transaction on Visualization and Computer Graphics (TVCG), 18(9): 1520-1536. [PDF]

2. A Framework of Interaction Costs in Information Visualization (2008)
   

   From 484 papers, we collected 61 interaction-related usability problems reported in 32 user studies and placed them into our framework of seven costs based on Norman's Seven Stages of Action.

   Lam, H. A Framework of Interaction Costs in Information Visualization. IEEE Transaction on Visualization and Computer Graphics (TVCG), 14(6): 1149-1156. [PDF]

3. Guidelines to Increase Utility of Empirical Studies (2008)

   Our experience in evaluating multiple-VIR interfaces prompted us to think more deeply into challenges in evaluating information visualization. Thispaper stemmed from our experience in conducting the summary sythesis of 19 multiple-VIR interfaces.

   Lam, H. and T. Munzner. (2008). Increasing the Utility of Quantitative Empirical Studies for Meta-analysis. In Proceedings of the 2008 CHI Workshop on BEyond time and errors: novel evaLuation methods for Information Visualization, pp. 21-27. [PDF]

I have built tools for a variety of use cases and audiences, including data analyses for domain experts to general explorations for the curious.

1. Session Viewer: Visual Exploratory Analysis of Web Session Logs (2006 - 2007)
   

   Web session logs are time-stamped sequences of user actions in a web search, for example, submitting a query, or, clicking on a result returned by the search engine. We built a tool called Session Viewer to investigate how visual exploratory data analysis can help analyze this large and complex data. We evaluated how analysts interact with Session Viewer in a contextual inquiry.

   Lam, H., D. Russell, D. Tang, and T. Munzner. (2007). Session Viewer: Visual Exploratory Analysis of Web Session Logs. In Proceedings of the IEEE Symposium on Visual Analytics Science and Technology (VAST), pp. 147-154.

   [Version 2: PDF (3.8M); MOV (25MB)]
   [Version 3: PhD thesis Chapter 7] [Evaluation: PhD thesis Chapter 8]

2. Line Graph Explorer (2006)
   

   I worked with Dr. Robert Kincaid to develop a scalable visualization for hundreds to thousands of line-graphs (xy-plots) as an internship project at Agilent Laboratories in California.

   Kincaid, R. and H. Lam. Line Graph Explorer: Scalable Display of Line Graphs Using Focus+Context. In Proceedings of Advanced Visual Interface (AVI 2006), pp. 404-411. [PDF; AVI (31MB)]

3. MusicLand: Exploratory Browsing in Music Space (2005)
   

   MusicLand is our first attempt to look at search behaviour where the target is not precisely defined. We call such behaviour exploratory (to discover a local neighbourhood of interest) and browsing (to surf interesting neigbhourhoods in detail). The data used are annotated music files.

   Lam, H and T. Munzner (2005). MusicLand: Exploratory Browsing in Music Space. Poster presented at InfoVis 2005, Minneapolis, MN, USA, Oct 23-25, 2005.
   

   [Poster summary (PDF)]
   [Poster (PPT)]
   [Video AVI (DivX, 53MB)]
   [Video AVI (Cinepak zipped, 80MB)]

4. Summary Thumbnails: Readable Overviews for Small Screen Web Browsers (2004)
   

   This is my internship project at Microsoft Research at Redmond, Washington, USA, working with Dr. Patrick Baudisch and Dr. Mary Czerwinski. The idea is to render web pages as thumbnails on PDA-sized screen to preserve the layout of the page, and automatically display selective readable text to allow for browsing.

   Lam, H and P. Baudisch. Summary Thumbnails: Readable Overviews for Small Screen Web Browsers. In Proceedings of the ACM SIGCHI Conference on Human Factors in Computing Systems (CHI 2005), pp. 681-690.
   
   [PDF (2.0MB); MOV (28MB); WMV (30MB)]

5. Medical Laboratory Result Reporting System (2002-2004)
   

   This is my M.A.Sc. thesis work. Current paper reports are difficult to access, share and read. Electronic delivery to mobile devices can mitigate the access and sharing problems, but the constraints of the devices remain difficult design challenges.

   In this project, we employed a number of visualization techniques including object display, pre-attentive vision, hierarchical + elision display, perceptual layering and detail-on-demand to effectively display laboratory results on PDA-sized screens.

   [AVI (3.25KB, requires TechSmith Codec); PDF (Thesis)]

   Lam, H., A.E. Kirkpatrick, J. Dill, and M.S. Atkins (2006). Effective Display of Medical Laboratory Report Results on Small Screens: Evaluation of Linear and Hierarchical Displays.  International Journal of Human Computer Interaction 21(1): 73-89. [PDF]

6. CZTalk: an Online Discussion Interface (2000-2001)
   

   This is my B.A.Sc. thesis work. The idea is to display discussion messages in a Focus+Context, 2 1/2-D network instead of in a hierarchical tree to allow more flexible, and closer representation on how people think and learn.

   [AVI (1.38MB, requires TechSmith Codec)]

   Lam, H., B. Fisher, and J. Dill (2005). A Pilot Study of CZTalk: A Graphical Tool for Collaborative Knowledge Work. In Proceeedings of the 38th Hawaii International Conference on System Sciences, Track 4, Volume 4, 104.3. [PDF]

We studied the use of overview (context) and detail (focus) in visualizations that display data at multiple levels of detail. We employed a wide range of methods: visual study, user study, and systematic review.

1. Image Transformation and Visual Memory (2006)
   

   This is part of a series of studies where we evaluated the perceptual costs of image transformations including scaling, rotation, rectangular fisheye, and polar fisheye. We also looked at the role of grids in alleviating these costs.  In this work, we looked at the effects of transformations on visual memory.  We found that visual memory was invariant to scaling up to 0.2x reduction, clockwise rotation up to 45 degrees, and fisheye transformations up to d=1.  We also verified the beneficial effects of grids where their presence extended the threshold of performance degradation, and/or improved performance in all transformations except for the fisheye polar case.

   Lam, H., R.A. Rensink, and T. Munzner. Effects of 2D Geometric Transformations on Visual Memory. In Proceedings of the 3rd Symposium on Applied Perception in Graphics and Visualization (APGV'06), pp. 119-126. [PDF]

   Lam, H, T. Munzner, and R.A. Rensink (2006). The Invariance of Visual Long-term Memory to Geometric Transformation.  Journal of Vision 6 (6), 983a. [Abstract]

2. Overview use in Multiple Visual Information Resolution Interfaces (2007)
   

   Using the visual encoding for line graphs in Line Graph Explorer, we looked at the perceptual requirements of visual targets on overview such that participant would (or could) select areas of interest for more detailed examination in the detail view. We found that in order to be effective, visual targets on the overview had to be simple and of narrow visual span. Otherwise, at least 20% of our participants chose to use the detail view alone.

   Lam, H., T. Munzner, and R. Kincaid (2007). Overview Use in Multiple Visual Information Resolution Interfaces. IEEE Transactions on Visualization and Computer Graphics (TVCG) 13(6): 1278-1283. (Presented at Infovis'07) [PDF]

3. A Guide to Multi-Level Visualization Interface Design (2010)
   

   We derived design guidelines to guide multiple visual information resolution (VIR) interface construction. We reviewed 22 existing multiple-VIR interface studies and cast our findings into a four-point decision tree:

   1. When are multiple VIRs useful?
   2. How to create the low-VIR display?
   3. Should the VIRs be displayed simultaneously?
   4. Should the VIRs be embedded, or separated?

   Lam, H. and T. Munzner (2010). A Guide to Visual Multi-Level Interface Design From Synthesis of Empirical Study Evidence. Synthesis Lectures on Visualization Series, Lecture 1, Morgan Claypool, November 2010. ISBN: 9781608455928 paperback, ISBN: 9781608455935 ebook. (117 page monograph).

1. Medical Research at BC Cancer Agency

   The Advanced Therapeutic Laboratory (1994)

   I investigated multidrug resistance in cancer chemotherapy when I was at medical school. Resistance in drugs has been a difficult problem for many treatments, especially in chemotherapy.

   Terry Fox Laboratory (1992)

   I studied factors that control stem-cell proliferation and differentiation. In the path of maturation, cells are believed to be induced to differentiate instead of proliferate by various chemical signals in the body. More details can be found at Dr. Gerald Krystal's website.

2. Chemistry Research at UBC

   Physical Chemistry (1993)

   In my first undergraduate thesis (Excess partial molar enthalpies of 1,2-propanediol and water in 1,2-propanediol-water mixtures), I studied the physical properties of different mixing schemes of a oil-like (hydrophobic) liquid with water (hydrophilic).

   Analytical Chemistry (1990)

   This is a summer NSERC scholarship in my first year at UBC. In the project, I developed an analytical method to detect Lead concentration of drinking water. The main concern there was portability so that the instrument could be used in the fields. Also, the amount of sample required in traditional analytical methods was typically large, which may be another concern for some situations. Both concerns could be addressed by a technique called Flow Injection Analysis. Results from the project was adapted as a laboratory experiment in a 3^rd year chemistry course at UBC, which I took 2 years later.

• Lam, H., E. Bertini, P. Isenberg, C. Plaisant, and S. Carpendale (2012). Empirical Studies in Information Visualization: Seven Scenarios. IEEE Transaction on Visualization and Computer Graphics (TVCG), 18(9): 1520-1536.
• Lam, H.(2008). A Framework of Interaction Costs in Information Visualization. IEEE Transactions on Visualization and Computer Graphics (TVCG), 14(6): 1149-1156.
• Lam, H.and T. Munzner (2008). Increasing the Utility of Quantitative Empirical Studies for Meta-analysis. In Proceedings of the 2008 CHI Workshop on BEyond time and errors: novel evaLuation methods for Information Visualization, pp. 21-27.
• Lam, H., D. Russell, D. Tang, and T. Munzner (2007). Session Viewer: Visual Exploratory Analysis of Web Session Logs. In the Proceedings of the IEEE Symposium on Visual Analytics Science and Technology (VAST'07), pp. 147-154.
• Lam, H.,T. Munzner, and R. Kincaid (2007). Overview Use in Multiple Visual Information Resolution Interfaces. IEEE Transactions on Visualization and Computer Graphics (TVCG) 13(6): 1278-1283. (Presented at Infovis'07)
• Kincaid, R., H. Lam. (2006). Line Graph Explorer: Scalable Display of Line Graphs Using Focus+Context. In Proceedings of the Workshop on Advanced Visual Interfaces (AVI'06), pp. 404-411.
• Lam, H., R.A. Rensink, and T. Munzner (2006). Effects of 2D Geometric Transformations on Visual Memory. In Proceedings of the 3rd Symposium on Applied Perception in Graphics and Visualization (APGV'06), pp. 119-126.
• Lam, H., T. Munzner, and R.A. Rensink (2006). The Invariance of Visual Long-term Memory to Geometric Transformation. Journal of Vision 6(6), 983a.
• Lam, H., A.E. Kirkpatrick, J. Dill, and M.S. Atkins (2006). Effective Display of Medical Laboratory Report Results on Small Screens: Evaluation of Linear and Hierarchical Displays. International Journal of Human Computer Interaction 21(1): 73-89.
• Lam, H. and P. Baudisch (2005). Summary Thumbnails: Readable Overviews for Small Screen Web Browsers. In Proceedings of the ACM SIGCHI Conference on Human Factors in Computing Systems (CHI 2005), pp. 681-690.
• Lam, H., B. Fisher, and J. Dill (2005). A Pilot Study of CZTalk: A Graphical Tool for Collaborative Knowledge Work. In Proceedings of the 38th Hawaii International Conference on System Sciences, 104.3.

• Lam, H. and T. Munzner (2010) A Guide to Visual Multi-Level Interface Design From Synthesis of Empirical Study Evidence. Synthesis Lectures on Visualization Series, Lecture 1, Morgan Claypool, November 2010. ISBN: 9781608455928 paperback, ISBN: 9781608455935 ebook. (117 page monograph).

• Dork. M, H. Lam, O. Benjelloun (2013). Accentuating visualization parameters to guide exploration. CHI Extended Abstracts 2013: 1755-1760.
• N. Gupta, A. Y. Halevy, B. Harb, H. Lam, H. Lee, J. Madhavan, F. Wu, C. Yu. (2013) Recent progress towards an ecosystem of structured data on the Web. In Proceedings of the IEEE 29th International Conference on Data Engineering (ICDE), p.5-8.
• J. Madhavan, S. Balakrishnan, K. Brisbin, H. Gonzalez, N. Gupta, A. Y. Halevy, K. Jacqmin-Adams, H. Lam, A. Langen, H. Lee, R. McChesney, R. Shapley, W Shen (2012). Big Data Storytelling Through Interactive Maps. IEEE Data Eng. Bull. 35(2): 46-54.
• Lam, H. and T. Munzner (2005). MusicLand: Exploratory Browsing in Music Space. Poster presented at InfoVis 2005, Minneapolis, USA.
• Lam, H. (1996) Clinical Study on Risk Factors of Inflammatory Breast Cancer. Presented at the Ottawa Civic Hospital, Ottawa, Canada.
• Lam, H. (1992) Factors Affecting Human Stem Cell Differentiation and Proliferation. Poster presented at the Health Sciences Student Research Forum, Vancouver, Canada

• Ph.D. (2008): Visual Exploratory Analysis of Large Data Sets: Evaluation and Application. University of British Columbia, Canada.
• M.A.Sc. (2004): Displaying Medical Llaboratory Reports on Small Screens. Simon Fraser University, Canada.
• B.A.Sc. (2001): From CZWeb to CZTalk: A Graphical Tool for Online Discussion. Simon Fraser University, Canada.
• B.Sc. (1993): Excess Partial Molar Enthalpies of 1,2-Propanediol and Water in 1,2-Propanediol-Water Mixtures. University of British Columbia, Canada.

• BELIV: BEyond time and errors: novel evaLuation methods for Information Visualization, 2010 - present

• InfoVis: IEEE Symposium on Information Visualization, 2009 - 2011, 2013
• PacificVis: IEEE Pacific Visualization Symposium, 2010

• NSF: Visualization panel reviewer, 2009