Category Archives: Usability

CFP: Workshop on Usable Security, due Nov. 6

NDSS logo

I am helping out on the Program Committee for the  USEC’14 workshop.  The workshop will take place as part of the Network and Distributed System Security (NDSS) Symposium in February 2014 in San Diego. Consider submitting your work.

The workshop on Usable Security invites submissions on all aspects of human factors and usability in the context of security. USEC’14 aims to bring together researchers already engaged in this interdisciplinary effort with other computer science researchers in areas such as visualization, artificial intelligence and theoretical computer science as well as researchers from other domains such as economics or psychology.


Nov. 16, CapCHI event, David Barrera on usability and security of Android

photo by laihiu

David Barrera will be speaking on Usability and Security  of Android, Google’s Open Source Smartphone System

Date: Tuesday November 16, 2010
Time: 6:00pm
Place: TheCodeFactory, 246 Queen St., Ottawa

The adoption of Android-based smartphones is growing at a rapid pace (nearly 200,000 activations per day) which has placed Google among the top smartphone system vendors worldwide. Despite Android’s open source nature, there are a number of security and usability issues that have yet to be addressed. This talk will cover issues related to security prompts and notices on the device, permission granting, smudge attacks and application security. We will discuss how these issues affect other platforms as well, including Apple iOS, Blackberry, and Symbian.

David Barrera is a 1st year Ph.D. student in Computer Science at Carleton University under the direction of Paul Van Oorschot. His research interests include smartphone and mobile OS security, data visualization, network security and IPv6.

International Conference on Trust and Trustworthy Computing

TRUST2011 is scheduled for June and the Call for Papers is out. I am on the program committee for the socio-economic strand and papers are due February 15, 2011.

TRUST 2011 is an international conference on the technical and soci-economic aspects of trustworthy infrastructures. It provides an excellent interdisciplinary forum for researchers, practitioners, and decision makers to explore new ideas and discuss experiences in building, designing, using and understanding trustworthy computing systems.

Symposium on Usable Privacy and Security (SOUPS 2011)

SOUPS logoThe Call for Papers for SOUPS 2011 is now out. It is my pleasure to be on the program committee again.

The symposium will bring together an interdisciplinary group of researchers and practitioners in human computer interaction, security, and privacy. The program will feature technical papers, a poster session, panels and invited talks, discussion sessions, and in-depth sessions (workshops and tutorials). This year SOUPS will be held in Pittsburgh, PA.

Papers are due March 11, 2011.

Symposium on Usable Privacy and Security (SOUPS 2009)

soups2009SOUPS 2009 is underway in lovely Southern California. Google is hosting the conference this year.

SOUPS is the major conference in the field defined by the intersection of usability and security. The conference includes two tutorials, which took place yesterday, 15 technical research papers, a panel, break-out discussion sessions, and a keynote address.

Check out the conference program at the web site:

SOUPS – Symposium On Usable Privacy and Security

The science of waiting lines

I hate waiting in lines. If I go to a restaurant that has anything more than 5 people waiting, I leave. The thought of queuing up outside a store for one of those big holiday sales is completely foreign to me. I often arrange my daily schedule to avoid waiting in lines: I drive in off-peak hours, eat when others are working, and avoid crowded shopping centers in favor of small locations.

The one thing more frustrating that waiting in a line is waiting in a bad line. You know, those lines that are poorly designed, without clear guidance about where to wait, or what you are waiting for. Or lines where it is clear that there are not enough services at the end (cashiers, clerks, or kiosks) to handle the number of people waiting.

What makes this so frustrating is that waiting lines don’t have to be so terrible. There is a science of waiting lines, and if organizations follow the science they can make their lines more efficient and more pleasant. Waiting times are a necessary evil. Having some form of a queue is often the best way to ensure that a system or service works as efficiently as it can. Queues make sure that each resource, be it a cashier or a customs official, never goes idle waiting for the next customer. Queues that are too long can drive customers away, but queues of the right length can increase efficiency and save money.

Donald Norman, a popular usability guru, has recently outlined some valuable design principles for making good waiting lines. Many of these are common sense, but when they are not followed the effects are usually obvious, and unpleasant.

One of the most important principles is that human emotions dominate the experience of waiting in lines, and that emotions are affected by context. Setting a pleasant context for a wait in a line can make all the difference. A location that is warm, bright, cheerful, and welcoming will be far better tolerated. This Disney theme parks, which are synonymous with long lines, are very good at setting a good context for a waiting line, often having costumed characters entertain people while they wait.

My son, who has more patience than me, recently got into one of those multi-hour waiting lines for a Boxing Day sale at an electronics store. The store did many things to make the wait as pleasant as possible: they gave out coffee and snacks, they gave people a number so they could take a break and return to the line, and they held raffles for free merchandise. This is also a good example of a related design principle: keep people occupied. Peoples’ perceptions of time and space are influenced by their surroundings. Many service environments, such as waiting rooms, now have TV’s and advertising displays to keep people occupied.

Emotions spread from person to person. So, in managing a good waiting line, it is important to watch for and address any negative emotions. This means paying attention to the most upset customers so that their negative emotions do not spread to the other people waiting in the line.

Another design principle is to eliminate confusion by making it clear and unambiguous where the line starts, where it ends, and how it works. Perhaps the worst waiting experience is finding out you have been waiting in the wrong line. Some of the best lines I have seen at airports are where one employee at the head of lines provides reassurance that people are entering the correct queue.

Providing feedback on how the line is progressing is also important. Nira Munichor and Anat Rafaeli from Isreal recently conducted a study of telephone waiting lines. They had participants either listen to music while they waited for a telephone service, or the people heard music and one of two spoken messages. The first message apologized for the wait and asked people to remain on the line. The second message provided information about where the person was in the line (e.g., “You are currently third in line”). Call abandonment rates (the frequency by which callers hang up) were 50% lower with the informative position information than with the music or apology conditions, and the customer experience was described as much better. It is possible to design good waiting lines, even for the telephone.

Waiting lines also need to be appropriate: long waits for trivial reasons or trivial goals won’t make any sense. Waits also have to seem fair. If there are a lot of people waiting and yet only a few service locations open, such as at a bank, then this appears to be unfair.

A lot can also be done to improve the waiting line experience by changing the way the line works. Certain kinds of layouts can make lines more efficient, faster, and therefor more pleasant. You may have seen cashier stations at cafeterias, for example, that have two sides for serving customers on the left and the right. This is because the process of cashing out a customer can be inefficient, with time spent while the customer puts items on the counter, finds money, packs up the items again, etc. While a customer is busy doing those things on one side, the cashier can serve another customer on the other side. For situations like this, this kind of arrangement makes the lines work much better.

Another example of changing the way a line works can be seen in drive-through restaurant windows. These restaurants often have one place for giving a food order, another place for paying for the food, and a third place for picking up the food. And, these windows are often far apart. This physical distance means that, as long as there are a few customers, there are built-in delays in the process. This is important because preparing the food takes time, but by designing the line in this way customers are seldom left waiting for their food to be prepared — by the time they have visited all the windows the food is ready.

Another design decision is having multiple servers with multiple lines, as is usually done in super markets, or multiple servers and one line, as is usually done in banks. One line can appear to move faster and appear more fair, and a single waiting line automatically adapts if one of the servers is slow or encounters an unusual circumstance (one of those people with dozens of coupons).

Of course, sometimes the best design is to avoid the line in the first place. Reservations are a method of avoiding waiting lines. I recently traveled to Europe and visited a number of museums and art galleries. I did a lot of research to make as many reservations as I could, even if it cost more, to avoid the lines. Even though every guide book I read explained how to do this, I was amazed at the thousands of people who ignored the advice and waited in line after line. If you get to Rome and want the visit the Vatican museum, make a reservation for one of their wonderful guided tours and don’t wait in the infamous lines (and don’t miss the Borghese Gallery, where you have to have a reservation).


Donald Norman, D. (2008.) The Psychology of waiting lines.

Munichor, N. & Rafaeli, A. (2007). Numbers or apologies? Customer reactions to telephone waiting time fillers. Journal of Applied Psychology, 92 (2), 511–518.

My favorite comedian, John Pinette, also hates waiting in lines:

Engineering versus design at Google

An interesting article from Wired on engineering versus design at Google. Douglas Bowman, Google’s visual design lead, is leaving because he says there is too much emphasis on engineering and not enough on design. While I am a big fan of having empirical evidence when making decisions, I can understand where it could be frustrating to have to run studies to decide on the width of a line or a shade of blue.

Google’s Data Culture Drives Designer Crazy — and Out

… he got fed up with constant pushback from a bureaucracy that seeks empirical justifications for choices made within what is essentially is an art form — and often about relatively insignificant details.

Model privacy notice for US financial industry based on user research

Recently, the FTC and eight federal regulators of the financial industry in the US have proposed adoption of a model privacy notice form. This form would be used by financial institutions to inform customers about the institution’s privacy practices, and provide opt-out opportunities for the sharing of personal information.

This model privacy notice was developed using iterative, user-centred research and development. A report by the Kleimann Communication Group describes the research that went into the prototype. The goal of the project was to develop a paper-based privacy notice that was comprehensive, comprehensible, standardized to allow comparisons, and compliant with existing regulations.

The research and development process was conducted over 16 months and included 2 focus groups of 10 people each, preference testing with 7 participants, pre-testing with 4 participants, and diagnostic usability testing with 35 participants in 5 US cities. The model notices were revised during each of these steps. Page 1 of the final 3 page form is shown below.


The prototype privacy notice contains 4 main sections: (1) a “key frame” that answers generic Why, What, and How questions concerning the sharing of personal information; (2) a disclosure table that states the practices of the specific financial institution using the form (e.g., information is shared with affiliates for marketing purposes), and whether the customer can control those practices (i.e., opt-out options); (3) a secondary frame that provides definitions (e.g., “affiliates”) and answers to frequent questions (e.g., Why can’t I limit sharing?); (4) and an opt-out form where customers indicate their privacy choices.

The final prototype notice appears to be a usable and flexible tool for gaining understanding and consent. Follow-up evaluation is being planned once the notices have been used with the general public.

The development methodology and the resulting model forms might be applied to other areas where notice and consent are required. For example, participant consent forms used during research on human subjects are often overly long and complicated, often with the intent of appeasing an ethics review board rather than informing the participants. Perhaps this approach used for privacy notices could be used to improve and standardize these consent forms.