Catching usability issues with automated tests
- Hi Alain,
A belated response to your belated response :)
On 29 Aug 2006, at 19:25, Desilets, Alain wrote:
> That's REALLY interesting. Can you tell me more about how you think
> usability issues can be embodied in automated tests? That has always
> seemed a bit of an achille's heel of agile w.r.t. to agility, i.e. the
> fact that there is no way to automatically measure usability.
An excellent question. Some approaches I've used:
1) Use heuristics
2) Split the usability requirements up into things you can test and
things you cannot
3) Automate the detection of changes that need a human review.
4) Make sure that you're UI concepts are embedded in the code - then
you're normal automated tests should catch them
One example of 1--3 snipped from something I wrote here ages ago
> I'm often involved with testing web sites for accessibility. Now
> producing an accessible site involves human judgement. There is no
> automated way to say whether a particular piece of alternative text
> "makes sense", or that a piece of prose on a link title gives
> enough information to the user in a particular context.
> But I /can/ write automated tests that check
> * all pages pass the WAI WCAG validation suite without fatal errors
> * all images have ALT attributes
> * all ALT attributes come from the url/image/alt-text mapping
> dictionary that I've checked
> * link text comes from the url/url mapping table that I previously
> * that the MD5 hash of every page has an entry in the "a human
> reviewed this" table
> * etc.
> The automated tests that build up over time catch the majority of
> accessibility issues, which allow me to give much more focussed
> attention to the bits that do require a vague approximation of
> actual intelligence.
An example of (4) would be a workflow I designed that always had one
"happy path" from each stage - the route that most users would follow.
This was highlighted in the visual appearance of each page of the
workflow. The "happy path" button was a different colour and size,
and always appeared before any buttons on the page on the right hand
Now - we already had a system for implementing basic HTML workflows
(a little state transition network glued to some basic templating).
The developers could have just implemented workflows with a "happy
path" using this, styling the default-route buttons appropriately.
The problem with doing this is that none of the design concepts of
the "happy path" route end up in the code. Later on somebody could
implement pages with multiple "happy path" buttons, or ones that are
in the wrong position, or pages with no default route.
So instead we subclass the state transition code and add the
HappyPath concept. We make sure that it's impossible to instantiate
an instance of a workflow that has pages with multiple happy paths,
or no happy path at all.
We subclass the template code so that happy path buttons are
automatically styled appropriately and are only permitted in certain
areas of the page layout. We even make the CSS for the "happy path"
button linked to an id rather than a class so it's impossible to have
more than one on a page.
And of course, since we developed using TDD, we have automated tests
that will break if somebody comes along later and tries to change the
code to break those design decisions.
This is why it's so vital to help the development team understand the
underlying decisions behind the design of the user experience. If the
developers don't see or understand them then they never get embedded
in the code. If they don't get embedded in the code they won't get
automated tests. If they don't get automated tests they'll get broken
later in the project.
Make vague sense?
Does anybody else have more examples - alternate techniques?
- I just logged in to the PMI site as a member. It had been a while, so I wasn’t sure of my username and password (it’s been a few months since the last time I used it). Of course, one of first thing you would expect is to know whether the system did recognize you or not. Guess what, nowhere on the page that came up is there any mention of my name. As far as I can tell, I don’t even know if I’m really logged in (ok, I see log out somewhere so I’ll assume I’m logged in). My reflex was to look on the page everywhere ( I had to scroll because the first page is long). Because it puzzled me a bit, my next reaction was to look at the left menu and see if I could get my account details. No luck, no menu entry is clearly labelled that way.
- Ah ah, just found the problem. There is a Membership information home button which I thought wrongly was the Menu title (it was not underlined, is of a different color and background than all other menu items, and because it doesn’t look clickable I actually dismissed it as a header and didn’t even read the text anyway). However, it made no sense I could not see my account info, so I investigated further the UI (and then realized what that header actually was). When I clicked on it, it finally got me my account information. I figure that this is normally the first page you get when you log in. For some reason, they decided to put a two pager publicity there instead (“PMI's 250,000 Member Race”).
- Anyway, it now makes me feel a little bit stupid that I lost so much time figuring this out as a user. A simple Hi Pascal on the login page would have just avoided the whole freaking thing, and that menu item that doesn’t look clickable too… Oh well, maybe it’s just me, I’m probably bellow their required target user intelligence level…
- Isn’t that pretty basic usability stuff? And we are talking a fairly prestigious site here (I heard the PMI is targeting 250,000 members worldwide)…
Anyway, the point I want to make is that even basic stuff like that is very common in the field. This leads to software that is harder to use than it should (ever heard of the digital divide?, I think stuff like that contributes heavily to it) and even frustrates and angers people at times. Frankly, I doubt they even had one real user test that part of the site before they put it out there…
Pascal Roy, ing./P.Eng., PMP
Elapse Technologies Inc.
From: agile-usability@... m [mailto: agile-usability@... m ] On Behalf Of Phlip
Sent: 6 septembre 2006 11:15
To: agile-usability@... m
Subject: Re: [agile-usability] Catching usability issues with automated tests
Adrian Howard wrote:
> Some examples:legibility
> * Clean XHTML/CSS validation as a sign that the app will present well
> on all browsers
> * Using the presence of ALT tags as a sign of accessibility.
> * Using a computed "colour contrast" value as a sign of
> * Using the Kincaid formula or similar as a sign of readability* Use pure XHTML, so all that's accessable to the testage
* Run the site's pages thru Tidy and ask if it's accessible
Those tests sound weak, but some GUIs must internationalize and
localize correctly. Users of some rare language are probably familiar
and tired of the same dumb bugs in their GUIs. So switch to each
language and run all those tests again.
Next, do it even if your GUI is not HTML. MS's RESX files are of
course parsable as XML. I wrote
http://www.c2. com/cgi/wiki? MsWindowsResourc eLint
to scan the localized RC files looking for bugs. The program has an
extensible framework so you can add in any kind of test you can think
(At SYSTRAN, I spent a week writing the predecessor of that program. I
didn't notice they didn't nano-manage me during that week because they
were preparing to fire me. So when they did, my last act was to send
to all their executives a complete, automated report describing every
usability issue in every supported locale of every product, with
instructions how to run it again as part of their test server. The
total error count was >4k, in a company that's supposed to do
localization as a core competency!)
> 1) The system take a snapshot of the HTML/CSS of each page in a webThat is a technique under the umbrella I call "Broadband Feedback".
> app whenever somebody commits a change
> 2) Have a flag you can set on each page once you have reviewed them
> 4) Automatically notify you when a reviewed page changes, and have a
> failing test until you mark it as reviewed again
However, marking the test as failing is unfair to programmers, who
just want to check in an innocent change that doesn't break anything.
Move the "reviewed" flag from the bug collumn to some other collumn!
To achieve Broadband Feedback, automate the steps. The reviewer should
simply turn on a web interface that displays each changed GUI, and
reviews the change in the website - not necessarily in the target
program. That's why I wrote this:
http://www.zeroplay er.com/cgi- bin/wiki? TestFlea
(Click on a green bar.)
Imagine if you were the Sanskrit linguist for a project. Wherever you
are (even up a mountain in Nepal), you the project's web site. You get
a page like that; maybe it contains only unreviewed items, or maybe
unreviewed items have a grey spot next to them.
You inspect each GUI, verifying it uses correct Sanskrit, then you
switch the record to Reviewed.
For more complex usability needs, a test batch could also upload
animations of the program in use.
> No we cannot make a computer say whether an arbitrary thing isThe adoption of Agile techniques in the game industry, today, is at
> usable. However we can make a computer spot many of the instances
> where a usability design decision that we have made is actually being
> implemented correctly.
about the same place as Agile adoption was in business 6 years ago.
One common FAQ (unanswered even on many game projects) is this:
if the highest business value feature is Fun, how can you
write an acceptance test for that?
The answer is the same as for any other untestable property (security,
robustness, availability, usability, fault tolerance, etc.). Fun is a
non-functional requirement that generates many functional
requirements, each of which can be tested.
In games, that requires designers to occupy the Onsite Customer role,
and author their scenarios as scripts that test a game automatically.
A scenario should run a hero thru a level and ensure they kill every
Next, games are very dynamic and emergent. A change to a Maya file
here can cause a bug, or a lapse of Fun, in game levels over there.
One way to preserve Fun without locking down every file is to use Gold
Master Copy tests on aspects of a game's internal details.
For example, two runs thru the same scenario should generate the same
log file. A programmer could change the code in an innocent way,
changing the log file without afflicting Fun. But these tests should
run as often as possible, so the programmer will revert their change,
then make a _different_ innocent change which might work.
These kinds of tests can't even easily pinpoint bugs, so run them as
often as possible, so the cause must be the most recent edit. Treat
these tests as seismograph readings, of earthquakes deep beneath the
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