This course focuses on how to design and build secure systems with a human-centric focus. We will look at basic principles of human-computer interaction, and apply these insights to the design of secure systems with the goal of developing security measures that respect human performance and their goals within a system.
Design Methodologies
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En provenance du cours de University of Maryland, College Park
Usable Security
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À partir de la leçon
Week 2
Design: design methodology, prototyping, cybersecurity case study
Rencontrer les enseignants
Jennifer GolbeckDirector
Human-Computer Interaction Lab
[SOUND].
In this video, we're going to talk about different design methodologies.
In the interview that we saw previously,
some of these methodologies were mentioned and in fact, there's a number of ways that
people go about designing technology, including security systems.
This lecture will allow you to see some of those different methodologies.
We'll even look at some of them in work, and
you'll be able to see how to take some of those and
integrate them into a process when you're designing technology on your own.
First let's talk about the design process.
The goal ultimately is to see where these ideas come from.
This is what the design process gives us.
So you may come up with ideas just sitting by yourself in the room,
you may talk with users, you may talk with other designers.
Different design processes help us develop ideas in different ways.
There is a lot of different design processes.
In this video, we're going to look at a view of these including iterative design,
system centered design, user centered design, participatory design,
which we talked about a little bit in the interview, and designer centered design.
And let's talk first about iterative design because this in
fact fits into a lot of the other design methodologies we'll talk about.
If we start at the top, we come up with a list of requirements for
the system that we're going to build.
So if you were building an authentication system, for
example, you would come up with a list of requirements.
That could that users are able to login.
There are certain kind of checks that you have to do to make sure that their login,
say their password, is secure enough and so on.
Once you have that set of requirements, you then go and make a design.
And there's a lot of different ways that you can do that, and
we'll look at some of those in upcoming slides.
Once you make the design, then you go on to development.
You actually build the system, or
a prototype of the system, and then you test it.
The point of iterative design though is that in all of these stages,
we're going back and forth and cycling around.
So, once you define your requirements, it may be that you get to design and
then realize that some of your requirements weren't well spelled out.
So before you move on to the development phase, you may go back and
refine your requirements and then go on to design again.
Once you get to development, again, you may decide you need to change your
design or your requirements so, you can go back to one of those earlier phases.
Then once you move on to testing, you again may refine your requirements, but
you also may go back and change any of the other steps in this process.
So we're iterating around through a design, but we're doing it in
a way that we allow ourselves to adjust any of the requirements, design, or
implementation along the way.
Let's talk about System Centered Designed.
This is something that doesn't involve a lot of users or
resources, but it's one, it's a design methodology that happens a lot.
Essentially, we ask questions like, what can be built easily on this platform?
What can I create from the available tools?
And what can I do as a programmer that I find interesting to work on?
So, some of these are important questions.
For example, if you're building an authentication system for
a mobile device, it could be a huge amount of additional work if you want to
implement a totally novel authentication system,
when the platform already supports a few different ways of doing things.
So it's important to ask that because it may not be worth, dozens or
even hundreds of hours of additional work, to implement a totally new authentication
system, when you can rely on things that are supported already within the system.
At the same time, some designers use this as an easy way out of coming up
with anything new because they look at just what's available and
aren't willing to do extra work on top of it.
User Centered Design is a very popular way of doing design within human computer
interaction, and it focuses on the users and their importance to the system.
These designs are based on users abilities and
their needs, the context in which they're working, the work that they're doing and
the tasks that they have to accomplish.
The golden rule of interface design is really to know the user.
So when we talked about that previous example of doctors trying to
circumvent the security system on their
portable machines by putting styrofoam cups over the proximity detectors,
that's an example of where user centered design wasn't followed.
That security system did not take into account the user's abilities and
needs, the context, the work they were trying to do in the tasks, and
as a result, it was a poor system for them to work with.
User centered design tries to take all of these user needs into account, and
the design is based around that.
Participatory Design is really a type of user centered design,
where users are actually brought into the design process.
It addresses the problem that, sometime our intuitions as designers are wrong.
If we do interviews or
talk to people, they're not necessarily precise, and designers might not
know the user well enough to answer all the issues that come up during the design.
So, even if I talk to users and
come up with a list of tasks, they may tell me things that are useful, but when I
actually get into doing the design, I may have more questions that I can't answer.
The solution that Participatory Design offers, is that there is actually a pool
of end users that participate in the process of creating the design.
And, what I'd like us to do now, is actually to hear Dr.
Druin, Clegg, and Guha from our previous interview,
talking about Participatory Design since this is the core of their work.
>> So, so
participatory design, [INAUDIBLE] is when you involve the people, the target group,
that would be in users for your technology in the actual design of the technology.
There are various levels of engagement that you, that, that those groups can
take on so there's some people who sort of who, who might do like interviews and
observations and think of that as participatory design.
We tend to think of participatory design here,
actually bringing in those end users to give you, to generate design ideas that
you're actually going to, to take in and, you know, take with you.
But, so if you might also engage those, you might engage those participants and
doing some of that initial work in doing things and interviews and observations and
sells of other people.
but, but also you have, we have techniques where we're, we're,
we're actually working with the end users to generate those, those designs-
>> Mm-hm. >> in the prototypes.
>> And I think that also in our participatory design process,
in our co-design process, we work with our target user group is children.
So we work with children as design partners throughout the design process.
And that means that for
us, we view the children as, as integral to the design process as we are.
And we're an interdisciplinary team on top of that.
So, you know, my background is in education, Tammy's is in computer science,
Allison's got design and education and computer science.
So while we bring different disciplines to the table,
the children bring the perspective of, I am an eight year old now in 2014.
And I don't have that.
So my background in child development is as important as her,
her perspective on being eight in 2014.
And really going on this journey of design together with everyone as
an integral part is, is what I consider co-design.
Double >> I would say that the test is,
are you elaborating with your users?
Okay.
Is, so Tammy's a teacher.
And I could ask questions of Tammy, okay, like what she does as a teacher.
But Tammy needs to, I need to give an idea to Tammy and Tammy needs to say,
you know what, I like that idea but what if you changed it and you made
sure that five kids were in the classroom at the doing that at the same time.
And then I said, well, I don't know if that would work with five, but
you know what, three could work.
And then, and so, so, you know, in terms of, in terms of security, it's,
it's absolutely, you know, who who needs to be secure, who owns the security,
who, you know, and how can you have that elaborative conversation so
that you're not sure who's idea ultimately it was.
And that to me is the test of co-design.
>> And so it's not just about like, you know,
interviewing them about, so what do you do everyday and what are your practices or
that kind of thing, but it's more about interviewing them about what,
what should this thing that I'm designing look like?
Right? And
then get >> Yeah.
>> Yeah. >> And it's not just interviews, because.
>> Or, yeah.
>> Yeah, we do, used lots of different design techniques, and
we used a lot of artifact creation to actually bridge that conversation because,
you know, we can talk till the cows can roam between the three of us but,
you know, a lot of times people feel a little bit uncomfortable like,
sort of sharing ideas and going back and forth.
And so, then we add different techniques and, and many other people do
around the world in, in elaborating in creating that elaboration process.
>> Brainstorming is also a tool that's used in a number of design processes and
can be a design process by itself.
The graphic that we see here is part of the IDO design process.
You'll see a link in this weeks material to a Ted Talk that really gets into
detail about the interesting brainstorming design process they have there.
But again, we have an iterative process where we try to understand what
people need.
We observe them.
We visualize and predict what's going to happen.
We evaluate and refine our design.
And we implement it, and then go back through that cycle again.
So this is another iterative design process.
We have users and people giving us feedback.
We're testing and evaluating, but
we're trying to come up with a lot of ideas in the brainstorming process.
And so I'd like us now to look at a couple videos that give examples of good and
bad brainstorming design provided by Stanford.
>> You can borrow your neighbor's wrappers.
>> Pick out a paper towel.
>> Yeah, yeah.
Man I think a good idea would to put it be, to put the gum on the window but
I don't know if people think that's a good one or.
>> And when you want to save your gum, you just put it in,
keeps it at the correct temperature and
then you take it out when you're ready to eat it again.
>> I love it. >> That is awesome.
>> That is amazing.
>> I know. I just realized we
should go do it right now.
>> Yeah, let's go.
Let's go.
>> Humidifiers, every student has a little humidifier at their desk that they put
their gum in and it preserves it.
>> Do you like that?
>> You know, keep the gum at the correct consistency for re-chewing.
>> I think we're done with humidifiers.
[CROSSTALK].
>> Let's start simple.
>> And then what you really do is you blow it up and it goes up in.
>> I loved your first idea, who had the first idea?
>> You?
>> Did you have the first idea?
>> No, you did.
>> What was it?
I. >> It was something about bracelets.
>> I got an idea, so what if we had this container, but
not just any container, it's small enough to fit in your pocket and.
Partner up with a company like, I don't know, that makes a solution,
make it cheaper, but
>> Two, and they told me how to brace form effectively okay, so
Jackie, would you mind writing?
Be sure to capture all of the ideas, alright.
>> All of them?
>> Every idea's important,
even the wild ones cause that's how you get the really innovative solutions.
One thing, defer all judgement on other people's ideas and your own.
Okay? >> Mm-hm.
>> Right, so this is bad we're going to figure out how can we preserve gum, okay.
Lets gets some really wild ones.
Let's see how many we can get.
>> Okay, gum, ready, go.
Okay. >> You have a notebook with
gum wrappers in it.
>> Notebook with gum wrappers, awesome.
>> Lets build off of that, lets build off of ideas.
>> I love that.
>> So the wrappers, they could add flavor to it so
every time you put your gum in it.
>> Yeah. >> It's a new type of flavor.
>> With like powder.
>> And on top of that they can be warm so they can preserve the consistency.
>> Warm nice, I love that.
Flavor.
>> I love how you drew that.
That's really important to be visual because it helps you get other ideas.
>> Build off the what if the notebook came with different flavor powder flavors that
you could choose and empty it into the wrapper.
[CROSSTALK]. >> Oh yeah, I love that.
>> Flavor your own gum.
>> And you could, you could like trade.
Yeah. >> Yeah.
And you could download flavors from the internet.
>> I love that, we can even have like a multiplayer game.
Multiplayer game with trading.
>> My necklace?
>> An extra >> I almost interrupted you.
I don't ever want to don't ever want to cut anybody off, right?
We want to stay focused on our topic.
That's a great one.
I know, I have one.
>> Okay. >> There can be a student, and
this student, his,
his or her whole responsibility is to hold a blow dryer on the gum.
And then no matter [CROSSTALK].
>> Yeah, headline, that's one of the things I said, like if you have an idea,
spit it out, just give me a headline for
that, because it sounds like a really good idea.
>> Student holds blow dryer on gum.
>> Perfect, that's exactly what we want to do.
[NOISE].
>> Wow.
[NOISE].
>> Look how many ideas we have.
Let's try to count, let's try to count these.
How many do you think we got?
Yeah, we've been brainstorming for like, three minutes, and
already we've got 57 ideas.
>> Awesome.
>> Wow.
>> School rocks.
>> Alright, go team.
And to conclude, we finally have designer centered design, and Steve Jobs really
embodied this when he says, it isn't the consumer's job to know what they want.
And if we look at these phones, for example, this is a series of
phone by Nokia, all the left phones, and then the iPhone on the right.
The Nokia phones really show a progression of how mobile phones evolved, and
you see them approaching something with bigger screens and smaller buttons.
But the iPhone, when it came out,
really was a totally transformative design in cell phones.
And that's not something you necessarily could have come with if you
had a group of average cell phone users together.
It was a transformative design that threw out all of the things we knew about and
added something else.
Designers are trained to be good at coming up with these kinds of ideas.
And, a lot of times if you talk to average users, they may get stuck in ideas of
what they've seen before, in either other contexts, or the tools that they're used
to working with, and may not be able to come up with these radically new designs.
Designers are better at this and
so leaving some of the control in the designer's hands, so
they can look at consumers and know what will help them do their job better.
Even if the users don't know that themselves, can lead to great innovation.
So in conclusion, users can give a lot of valuable insight for design.
They can tell us about tasks, the context that they're working in, and their needs.
In addition, we want design methodology to support designers in
coming up with new ideas.
And, in almost all of these design methodologies,
we see that it's important to iterate to build better systems.
Try some ideas, prototype them, design them, test them and then go back and
refine at every stage of the process in order to come up with something good.
We're going to look at some case studies of examples of design and
development of systems in cyber security to really see how this plays out
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