Tag: reading

How to efficiently perform a literature review

Research is to see what everybody else has seen, and to think what nobody else has thought.
— Albert Szent-Gyorgyi (Hungarian Biochemist, 1937 Nobel Prize for Medicine, 1893-1986)

I got the idea to document the way I read papers from a discussion with Lode (he uses mostly the same approach as I do). I’m pretty certain this is obvious for many people, but I hope it may still be useful for others.

In this post I focus on processing lots of (related) papers in the least amount of time. I will not discuss how you find interesting papers, since this is fairly easy. Reading prestigious conference proceedings or journals in your field usually allows you to end up with a couple of seed papers that are representative for your specific area of interest. If you do research in ubiquitous computing, reading the proceedings of Ubicomp, Pervasive or Percom, and journals such as Personal and Ubiquitous Computing will get you along quite nicely. If you focus on the human-computer interaction aspects of ubiquitous computing, throw in the proceedings of CHI and UIST, together with the TOCHI and Human-Computer Interaction journals. The papers you find here will be stepping stones to related papers (and conferences) using the simple technique I will discuss in this post.

I estimate that of all papers I read, I only process 1 out of 5 in full detail. Most of the time when I find a paper that seems interesting, I start with skimming the paper briefly. I focus mostly on the abstract, the last part of the introduction (which should list the contributions), relevant pictures in the main matter, and the conclusion/discussion. I do several passes over the paper to validate my early understanding of what the authors did. I also go through the related work and references. This allows me to see if the authors refer to work that I don’t know but which could be interesting (which I mark for later processing). This will usually take little more than 5 minutes.

Now I have a pretty good idea whether the paper is interesting to me. If it’s not, I just go through the interesting references (if any) using the same process and stop there. If it is interesting, I go one step further, treating the paper as a seed paper that allows me to find other relevant work.

If the paper is not too recent, there will probably be (lots of) other articles that refer to this paper. Even if the paper is fairly new, it is still worth looking up papers that already refer to it. Looking up these articles allows me to discover relevant related work and to see how others critically describe this paper. A critical review could contradict of the results of the paper (e.g. through replication, such as Shumin Zhai’s work on target expansion), or might offer new insights (such as suggesting a new direction for research related to the original paper, as Yvonne Roger’s Ubicomp’06 paper did for Mark Weiser’s original Ubicomp paper). Both types of critical reviews are very useful for your own understanding of the paper.

I usually use Google Scholar to find citations (and downloadable versions of articles), since it indexes the major publisher databases (e.g. the ACM Digital Library, IEEE Xplore or SpringerLink):

After entering a title in Google Scholar, it presents you with a list of matching papers. Below each item, there is a link with the number of papers that cite it (indicated in orange in the figure below). In this case there are 118 citations:

After clicking on this link, Google Scholar shows all articles that cite the previous one, sorted by their relevance (in other words, the number of times these articles are themselves cited):

This approach to reading papers has one disadvantage: your reading list will quickly grow. You can end up with 30 more papers to read starting from just 1 interesting seed paper (which is what happened to me when I looked for papers that cited Intelligibility and Accountability: Human Considerations in Context-Aware Systems by Victoria Bellotti and Keith Edwards). In my opinion, this is actually an advantage as it allows you to quickly find many related (and hopefully interesting) papers. Furthermore, because you’re skimming papers, you never spend more than 5 minutes on papers that are not relevant or interesting.

After I have found a significant number of papers that I want to read, I of course will go through them in more detail. Papers that are very relevant for my work or give me the feeling they deserve a more thorough reading (e.g. because they provide many new insights), will be read from beginning to end. A few examples that I also discussed in my blog are: Range: Exploring Implicit Interaction through Electronic Whiteboard Design, Evaluating User Interface Systems Research and two chapters from Beyond the Desktop Metaphor: Designing Integrated Digital Work Environments.

A few related guides:
* Research Techniques by Alan Dix (especially the slides about gathering information)
* Reading AI from How to do Research At the MIT AI Lab

Thanks to Lode for having a look at an early draft of this post, and for providing the example of replication in HCI by Shumin Zhai.

Beyond the desktop metaphor: Lifestreams and Haystack

I spent part of my lazy Sunday on reading a few articles in Beyond the Desktop Metaphor: Designing Integrated Digital Work Environments, a book that Kris dropped on my desk a few weeks ago. It gives an overview of the state-of-the-art in integrated digital work environments and is edited by Victor Kaptelinin and Mary Czerwinski.

Beyond the Desktop Metaphor

I went through the chapters on Lifestreams by Eric Freeman and David Gelernter and Haystack by David R. Karger.

Lifestreams was an alternative to the desktop metaphor that was developed starting in 1994 and aimed to be a better way to organize your personal electronic information. One of the primary motivations for this work are the limitations of a static (hierarchical) filesystem. The problem with organizing our documents in the filesystem hierarchy is that information generally falls into fuzzy categories and that it is impossible for users to generate categories which remain unambiguous over time. Furthermore, users are forced to name their files, which often results in meaningless file names such as “draft1.doc” and “draft2.doc”. Names are an ineffective way of categorizing information, since their value decays over time. Traditionally, people do not name their documents as pointed out by Thomas Malone in his paper How do people organize their desks? Implications for the design of office information systems. He noticed that people often just create nameless stacks of related documents on their desk. Freeman and Gelernter discuss a few other problems with the desktop metaphor, such as no support for archiving, reminding and summarizing. The desktop metaphor does not make it easy to archive information, to put information somewhere we can later retrieve it but also remove it from our periphery. Users often place information on their desktop to remind them of tasks to do or leave an email in their inbox to remind them that they still need to reply to it. As the desktop has no semantic notion of reminding, users are just working around the system. Finally, summaries are needed in order to cope with all our electronic information. The authors state that summaries are often application-centric (e.g. an overview of your photo albums, an summary of your music, etc.), instead of system-wide.

I found it interesting that the authors do not see their architecture as another metaphor, but as a unified idea or system. They refer to Nelson’s concept of virtuality as opposed to metaphorics. Nelson (who also coined the term hypertext) argues that adherence to a metaphor prevents the emergence of things that are genuinely new. Trying to adhere to a metaphor may lead to strange results when new functions are added, for example having the drag a CD icon to the trash to eject it on Mac OS X.

A lifestream is a time-ordered stream of documents that functions as a diary of a user’s electronic life. Every document he or she creates is stored in the lifestream. Moving forward from the tail to the present, the stream contains more recent documents. Moving beyond the present into the future, the stream contains documents that the user will need (e.g. reminders, calendar items, etc.). The system has a few primitive operations that together support transparent storage, organization through directories on demand, archiving, reminding and summaries: new, copy, find and summarize. New and copy are used to create or copy documents in the lifestream or between lifestreams. Documents do not have to be named. The find operation allows users to search their documents. It creates a substream with the results of the query. These substreams are not static, but are updated on the fly whenever new documents that are relevant to their query appear. Users can allow substreams to persist, in order to quickly find information they need regulary (e.g. “emails from Joe”). Finally, summarize compresses a substream into an overview document. The method of summarizing varies according to the content of the substream (e.g. a music playlist, a prioritized to-do list, etc.). The figure below shows the Lifestreams user interface:

Lifestreams

It’s interesting to see that many of the ideas first explored in Lifestreams are currently supported by several applications. Archiving was one of Gmail‘s defining characteristics (“never lose a message again!”) when it was first released. Apple’s iApps such as iTunes offer summarization, dynamic substreams (“smart playlists”) and time-based visualizations. Desktop search tools such as Google Desktop, Apple Spotlight and Beagle offer a way to quickly find items on your computer. Some of them also offer saved searches (which is again similar to “dynamic substreams”). The authors also discuss this evolution. However, they feel that desktop search, while definitely a step in the right direction, is not sufficient. It only works if you know what to look for. People really need good browse engines instead of search engines. This statement is also made in the next chapter on Haystack where it is called orienteering.

Haystack can be seen as a generalization of Lifestreams. Haystack is a way to visualize and organize a user’s information, but does not restrict the visualization and categorization to be time-based. The authors try to find a solution for the fact that current applications force users to manage information in the way that the application designer envisioned it. This might not be the most natural way for the users, so Haystack gives the users more control over what kinds of information they store and how to visualize and manage it. In traditional email applications for example we can only categorize by the labels that are predefined (e.g. sender, subject. etc.), but not by our own features such as “needs to be handled by such-and-such a date”. The information may even be in the application, but no appropriate interface is offered to use it. Furthermore, every application manages its own data independently while we might want to relate data from different applications together (e.g. emails, articles, blog posts, pictures, songs, people, etc.). A user might also want to add a new data type. Consider the location field in a calendar event: this is just a string, while the user might want a richer presentation (Google Calendar can do this by linking to Google Maps by the way). Existing applications are very bad at extending existing types, since they offer no way of displaying the type, no operations for acting on it and no way of connecting them to other information objects in the application.

Haystack has a generic user interface architecture that supports impressive personalization. Users can for instance create a new “Send to Joe” operation by filling in part of the “Send to” operation, and saving it. Objects can be dragged upon each other to connect them: dragging an object onto a collection adds it to the collection, while dragging an object onto a dialog box arguments binds that argument to the dragged item.

Haystack

Custom workspaces can be constructed by drag and drop. The figure below shows a workspace specialized for writing a particular research paper, presenting amongst others relevant references, coauthors and outstanding to-do’s.

Haystack workspace

The system uses Semantic Web technology (more specifically RDF and URIs) to represent information objects, their attributes and relationships to other information objects. However, they do not enforce schema such as RDFS or OWL) in order to allow users to organize information the way they want. It is after all difficult to create an ontology that serves everyone’s needs. Consider for example the composer attribute of a symphony concept. A reasonable constraint is to restrict composers to be people. But this will prevent a user that is interested in computer music from entering a particular computer program as the composer. The authors state that schemata may be of great advisory value, but they argue against enforcing them. Apparently this is also known as a semi-structured data model.

I think this is the most impressive Semantic Web application I have seen, although I am also looking forward to test Twine and Powerset. I have barely touched upon everything that Haystack can do in this blog post so if you are not yet convinced, have a look at a paper that is pretty similar to the book chapter. The level of customization supported by Haystack reminded me of the Meta-UI concept (which I see as a user interface to manipulate an interactive system or its user interface) as discussed by Coutaz at Tamodia’06.

Although Lifestreams and Haystack would certainly improve the way we manage our data, I feel they both ignore an important type of information: information in the physical world. After all, a substantial amount of the information we process is non-digital. Last year, I had a project proposal for the course Actuele Trends in HCI (translated: “Current trends in HCI“) on improving the way we work with digital and physical information. Given that the students had little time for this project, the result was pretty nice.