Yesterday, I presented publicly my thesis to the Faculty of Informatics and Communication at EPFL. I also delivered the final version of the thesis to the registrars office of the university. This final version has an extra page at the end with some minor corrections (thanks to Darren Gergle for the suggestions). The PDF of the thesis can be downloaded here (371 pages, 42.7 Mb), while the slide deck I used for the presentation of this work can be downloaded here (57 slides with notes, 5 Mb).

As a part of the presentation of the work, I prepared a little animation which shows a typical interaction an user might have with STAMPS. Here you can download this movie (divx, 700 Kb).

Title: “Annotations of Maps in Collaborative Work at a Distance”

(thesis director: Pierre Dillenbourg)

Abstract:

This thesis inquires how map annotations can be used to sustain remote collaboration. When we are face-to-face, we can point to things around us. However, at a distance, we need to recreate a context that can help disambiguate what we mean. A map can help recreate this context. However other technological solutions are required to allow deictic gestures over a shared map when collaborators are not co-located. This mechanism is here termed Explicit Referencing.

Two filed experiments were conducted to investigate the production of collaborative annotations of maps with mobile devices. Both studies led to very disappointing results. The reasons for this failure are attributed to the lack of a critical mass of users (social network), the lack of useful content, and limited social awareness. More importantly, the study identified a compelling effect of the way messages were organized in the tested application, which caused participants to refrain from engaging in content-driven explorations and synchronous discussions.

This last qualitative observation was refined in a controlled experiment where remote participants had to solve a problem collaboratively, using chat tools that differed in the way a user could relate an utterance to a shared map.

Results indicated that team performance is improved by the Explicit Referencing mechanisms. However, when this is implemented in a way that is detrimental to the linearity of the conversation, resulting in the visual dispersion or scattering of messages, its use has negative consequences for collaborative work at a distance. Additionally, a primary relation was found between the pair’s recurrence of eye movements and their task performance.

Finally, this thesis presents an algorithm that detects misunderstandings in collaborative work at a distance. It analyses the movements of collaborators’ eyes over the shared map, their utterances containing references to this workspace, and the availability of ‘remote’ deictic gestures. The algorithm associates the distance between the gazes of the emitter and gazes of the receiver of a message with the probability that the recipient did not understand the message.

I. Arminen. Social functions of location in mobile telephony. Personal Ubiquitous Computing, 10(5):319–323, 2006. [PDF]

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This paper describes a conversational analysis of mobile phone conversations. The author tried to understand why and how people communicate their location in phone calls. The study extends the study of Laurier and Weilenmann in that this study elaborate the way in which location features in mobile users’ communicative behavior.

The author finds five situations in which location is used in mobile conversations. The first is the interactional availability (registered in the author’s dataset 15% of the time), or the availability to discussing the content of the phone call; The second is when the communication of location has an importance in the ongoing activity (22% of the cases), like when a car driver has to ask direction to a remote speaker. Seemingly, location might assume importance during the call as part of the activity the parties are involved into (9%) and as a prompt for future activities (48%, the majority of situations registered). Finally, location can be communicated even if it does not have any relevance for the activity at hand. In this case the author say that it has a social relevance (6% of the cases).

One of the author’s main implication of this study lies in the fact that according to him, location is never considered in purely geographical terms. Location is made important by the activities in which the parties are involved. Particularly, joint activities make spatio-temporal patterns.

A. Weilemann. “i can’t talk now, i’m in a fitting room”: formulating availability and location in mobile phone conversations. Environment and Planning A, 35(9):1589–1605, 2003. [pdf]

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This paper describes an analysis of recorded phone conversations. The author tried to understand the interrelations of location, activity, and availability. Indeed the author showed how in mobile phone conversations people exchange spatial information to infer the availability of the other to talk. Place can be inferred from the activity and vice-versa as people might have a good understanding of their peers whereabouts.

In this paper I investigate the ways in which participants in mobile-phone conversations orient to each other’s location, activities, and availability. By looking at data from recorded mobile-phone conversations, I use a conversation analytic approach to make initial observations on the character of mobile-phone conversations. I found that the frequent question “what are you doing?” sometimes caused a location to be given as part of the answer which shows how location, activity, and availability are strongly related. The participants thus obtained information about location, when this was considered relevant, through asking about activity. Location seemed especially relevant if it provided information about a future meeting. In some of the conversations where it seemed there was something going on where the ‘called party’ was located, the ‘caller’ reacted by initiating the conversation with a strategy which gave the called party a chance to end the conversation.

F. R. Bentley and C. J. Metcalf. Location and activity sharing in everyday mobile communication. In CHI ’08: CHI ’08 extended abstracts on Human factors in computing systems, pages 2453–2462, New York, NY, USA, 2008. ACM. [PDF]

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This paper presents an interesting study of location-disclosure in mobile phone conversations. They were interested in what kind of location and activity information is provided and how context might influence this information disclosure. The authors were particularly interested in the purposed of disclosing location and activity information. The authors felt that there was a need for understanding additional details of location-sharing in mundane situations and detailing the requests-for and responses-to location disclosures.

The authors used a pretty interesting technique, enrolling 7 participants who recorded their phone calls and then analyzed the resulting 176 recordings looking for patterns and similarities. First they parsed each message using annotation techniques refined in the conversation analysis domain (see Hutchby and Wooffitt, 1992, or Psathas, 1995). They also used qualitative techniques to look for affinity diagrams modeled on grounded theory.

They found several significant correlations, like the association of the disclosure of current location at the opening of a conversation. Past location was often disclosed in the middle of a sentence, while future location was more often disclosed at the end of a conversation. The authors distinguished 8 different situations in which location/activity is disclosed: 1) social awareness in order to feel more connected with other people; 2) managing availability; 3) planning to meet and micro-coordination to reach proximity; 4-7) disclosures to help others to check whether a person need anything from a particular location and to show caring; 5-6) disclosure as a mechanism to continue or to end the conversation; finally 8) as a process awareness in work.

An interesting finding is that according to the authors, is that people in the same social network often can infer each others’ whereabouts with a great precision. However they are often unsure of the exact transitioning times between activities or locations. Often these correct inferences are constructed from a small amounts of seemingly ambiguous data given past knowledge about that person’s interactions with the world. The authors call this a ambient noise, which is ofen thought by other researchers as something that needs to be filtered out. However, this study points out the importance of this information for enabling the function of grounding in the group, which serves coordination and therefore communication and collaboration.

This is the abstract of the talk I gave yesterday in Nottingham. I was invited by Geoff Underwood and Tom Foulsham to participate in their seminars held in the psychology faculty of the university. The slides of the talk can be downloaded here.

When we are face-to-face, we can point to things around us. However, at a distance, we need to recreate a context that can help disambiguate what we mean. A map can help recreate this context. However other technological solutions are required to allow deictic gestures over a shared map when collaborators are not co-located. This mechanism is here termed Explicit Referencing.

In this talk I will present a controlled experiment where remote participants had to solve a problem collaboratively, using chat tools that differed in the way a user could relate an utterance to a shared map. Results indicated that team performance is improved by the Explicit Referencing mechanisms. However, when this is implemented in a way that is detrimental to the linearity of the conversation, resulting in the visual dispersion or scattering of messages, its use has negative consequences for collaborative work at a distance. Additionally, an analysis of the eye movements of the participants over the map helped to ascertain the interplay of deixis and gaze in collaboration. A primary relation was found between the pairŐs recurrence of eye movements and their task performance.

Finally, I will present an algorithm that detects misunderstandings in collaborative work at a distance. It analyses the movements of collaboratorsŐ eyes over the shared map, their utterances containing references to this workspace, and the availability of ÔremoteŐ deictic gestures. The algorithm associates the distance between the gazes of the emitter and gazes of the receiver of a message with the probability that the recipient did not understand the message.

Lately, I have been thinking about this concept of location-based reminders (LBR). The idea is quite simple. a classical reminder is usually defined for a certain time, while a LBR is defined for a certain place. Setting a LBR opens a whole range of new possibilities as we can combine space and time in different manners to accommodate different behaviors (e.g., being reminded to buy milk while close to the grocery store but only on friday and sunday morning). I remember several projects done in the past that should have achieved exactly this point, like DeDe. However, they all failed because people are uncertain about their spatio-temporal patterns when communicating with other friends.

More specifically, the value of LBR is related to the fact of being reminded while being on the place. However the caveat is that either we are certain about our path in the city, in which case the value of the LBR is reduced, either we are uncertain about the path, the value of the LBR stays high but we can find ourself at home without milk.

Defining a spatio-temporal pattern is not a trivial task. Learning meaningful location is the first step but it is certainly not the added value of the application.

[Geominder, a simple LBR app] 

Reading one of the comics I like the best, Nathan Never, I learned an interesting German word: “alterszorn”. It means the ‘rage of age’, and refers to the habit of some older people to go over the polemical edge. The word was used by John le Carré, a British spy-novelist. Contrary to those that with older age become conservatives, calm, and in favor of the status quo, John le Carré took the inverse path because book after book he took a critical attitude towards people in charge, e.g., politicians, and their ability to manipulate, and falsify. This becomes more visible in one of his last books: Absolute friends.

I hope I will get alterszorn when I will more mature …

The other day, I had a nice chat with Paolo on the science behind these products that shields electro-magnetic (EM) waves. He recalled the formula that is used to calculate the skin depth of a conducting material in order to understand whether a certain EM signal can penetrate it or not.

An electromagnetic wave entering a conducting surface is damped and reduces in amplitude by a factor 1/e in a distance ∂ given by: 

where ω is the angular frequency of the radiation and σ the electrical conductivity of the metal. This distance is referred to as the skin depth of the conductor. The effect is caused by electromagnetic induction in the metal which opposes the currents set up by the wave E-field, and holds for oscillations below about 1012 Hz.

[more]

Sunday night I enjoyed an edition of Report, an Italian TV show, which presented a translated edition of Paul Kenyon’s “WiFi: a warning signal”, a BBC show. Kenyon’s thesis was straight forward: we know little about the biological effects of electromagnetic fields (RF). Studies reported controversial findings on the issue. In this situation we should adopt a precautionary approach against radio technologies. I fully agree with this thesis, full stop.

In this post I am not going into the debate of the scientific evidences in favor or against the bio-effects of RF. I simply accept that we do not know enough and the we should be cautious. My point is that radio signals are all around us and it is almost impossible to protect ourself from this electrosmog, or is it? As I studied environmental protection in my high-school degree, I believe we should follow some simple guidelines to reduce exposure to radio waves. To be more precise, we should reduce the dose of electromagnetic energy that we receive each day.

Some simple things that we can do at no cost:

– Turn off unused electric/electronic appliances (standby mode is not good);

– Place cordless phones and its base station far from bedrooms (especially DECT phones);

– Turn off the WiFi router when unused and during night time;

– Do not keep the mobile phone in the pocket when we are indoor (we can place it at a arm’s reach when we are home or in the office);

– …

Ok, fine, I can turn off the WiFi antenna, but what about the neighbor’s antenna, which is always on? And what about the GSM mast tower sitting 100 meters from my bedroom’s window? Well, in this case things are slightly more complicated. But still there are shielding solutions that we can put in place. In particular there are metallic nets and sheets that we can put on the walls that reduce substantially the signal strength of the microwaves reaching our appartment. The caveat is that these layers needs to be grounded with proper wiring otherwise they accumulate static energy and they loose their beneficial effect.

Also, there exist a carbonic paint for the walls that has a shielding effect. It is called Yschield, produced by a German company.

In summary, while we wait for a definite answer on the biological effects of these radio-waves, we better be cautious and reduce the amount of RF energy that our body takes each day. Just in case 🙂

Back in Florence, at CHI2008, I attended an interesting presentation of Tovi Grossman (DGP, University of Toronto), on volumetric displays. A volumetric display is a graphical device that forms a visual representation of an object in three physical dimensions, as opposed to the planar image of traditional screens that simulate depth through a number of different visual effects. The model he presented, in fact, used a fast-turning mirrors over which an image was projected thus giving a full sense of depth.

Tovi’s PhD thesis inquired how to interact with volumetric displays. Tovi and colleagues designed techniques for selection and interaction with 3D models represented through these displays. Their approach consisted in tracking the hands of the users and the users body using infrared markers and simple video analysis techniques. Volumetric displays are limited because they do not allow deictic gestures on the surface of the model.

The paper that he presented at CHI08 suggest different techniques that can help to overcome this limitation. For instance he suggest the possibility of using a spherical highlighter: a semi-transparent sphere that can be used to highlight a certain part of the model. Different colors can be used by different users. The access control to the view and feature of the drawing raises also interesting questions on how to grant equal participation to two or more users. Their idea, to this end, was that of splitting the drawing in two each sub-model could then be controlled by a single user. Of course, the natural extension of this system is the support of remote collaboration. However, Tovi’s thesis work did not cover this topic. We can think of many other issues that would raise when collaborators are not co-located. Interesting research questions might include how to best recreate the remote collaborator’s point of view on the model (a 3D minimap à la Greenberg & Gutwin?), and how to best offer explicit referencing support over a 3D surface.