Comics and happy problem solving

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I am in Eindhoven doing CSCW, silly ideas and other things with the USI students here. On the book shelf here is Scott McCloud’s “Understanding Comics” I picked this up last year and couldn’t put it down until I had read it all. There is another book on the shelves this year “Reinventing Comics” and I daren’t pick it up until I’ve done all the work I want to today!

Understanding Comics is both an apologetic for comics as an art form and also an exploration into what makes a comic a comic and how comics manage to captivate and give a sense of narrative and action through what are basically static images. As well as being a good read about comics and about art there seem to be many lessons there for other forms of narrative and animation especially on the web.

As far as I can see (without starting to read it and not being able to stop), Reinventing Comics seems to be about the way online delivery trough the web is giving new opportunities for Comic art … but maybe when I finish everything today I will find out.

Less graphic and less fun, but no less fascinating, I have been dipping into chapters of “The Psychology of Problem Solving“, which was also sitting on the USI shelves. I was particularly enthralled by descriptions of experiments where subjects were asked to accomplish divergent thinking tasks whilst either pushing their palms upwards from under a table, or pushing down from on top. The former a positive, ‘come to me’ gesture elicited more diverse ideas than the latter, negative, ‘go away’ gesture, even though the only difference was the muscle groups in tension. I’ve seen other research that shows how our brains monitor our body state to ‘see how we feel’ (like smiling therapy), but this was one of the most subtle and conclusive.

During the week I have had the USI students work through a design brief starting with silly ideas then moving through  structured analysis to good ideas. Perhaps I should have had them pushing up on tables in the first part and down in the second?

PPIG2008 and the twenty first century coder

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Last week I was giving a keynote at the annual workshop PPIG2008 of the Psychology of Programming Interest Group.   Before I went I was politely pronouncing this pee-pee-eye-gee … however, when I got there I found the accepted pronunciation was pee-pig … hence the logo!

My own keynote at PPIG2008 was “as we may code: the art (and craft) of computer programming in the 21st century” and was an exploration of the changes in coding from 1968 when Knuth published the first of his books on “the art of computer programming“.  On the web site for the talk I’ve made a relatively unstructured list of some of the distinctions I’ve noticed between 20th and 21st Century coding (C20 vs. C21); and in my slides I have started to add some more structure.  In general we have a move from more mathematical, analytic, problem solving approach, to something more akin to a search task, finding the right bits to fit together with a greater need for information management and social skills. Both this characterisation and the list are, of course, a gross simplification, but seem to capture some of the change of spirit.  These changes suggest different cognitive issues to be explored and maybe different personality types involved – as one of the attendees, David Greathead, pointed out, rather like the judging vs. perceiving personality distinction in Myers-Briggs1.

One interesting comment on this was from Marian Petre, who has studied many professional programmers.  Her impression, and echoed by others, was that the heavy-hitters were the more experienced programmers who had adapted to newer styles of programming, whereas  the younger programmers found it harder to adapt the other way when they hit difficult problems.  Another attendee suggested that perhaps I was focused more on application coding and that system coding and system programmers were still operating in the C20 mode.

The social nature of modern coding came out in several papers about agile methods and pair programming.  As well as being an important phenomena in its own right, pair programming gives a level of think-aloud  ‘for free’, so maybe this will also cast light on individual coding.

Margaret-Anne Storey gave a fascinating keynote about the use of comments and annotations in code and again this picks up the social nature of code as she was studying open-source coding where comments are often for other people in the community, maybe explaining actions, or suggesting improvements.  She reviewed a lot of material in the area and I was especially interested in one result that showed that novice programmers with small pieces of code found method comments more useful than class comments.  Given my own frequent complaint that code is inadequately documented at the class or higher level, this appeared to disagree with my own impressions.  However, in discussion it seemed that this was probably accounted for by differences in context: novice vs. expert programmers, small vs large code, internal comments vs. external documentation.  One of the big problems I find is that the way different classes work together to produce effects is particularly poorly documented.  Margaret-Anne described one system her group had worked on2 that allowed you to write a tour of your code opening windows, highlighting sections, etc.

I sadly missed some of the presentations as I had to go to other meetings (the danger of a conference at your home site!), but I did get to some and  was particularly fascinated by the more theoretical/philosophical session including one paper addressing the psychological origins of the notions of objects and another focused on (the dangers of) abstraction.

The latter, presented by Luke Church, critiqued  Jeanette Wing‘s 2006 CACM paper on Computational Thinking.  This is evidently a ‘big thing’ with loads of funding and hype … but one that I had entirely missed :-/ Basically the idea is to translate the ways that one thinks about computation to problems other than computers – nerds rule OK. The tenet’s of computational thinking seem to overlap a lot with management thinking and also reminded me of the way my own HCI community and also parts of the Design (with capital D) community in different ways are trying to say they we/they are the universal discipline  … well if we don’t say it about our own discipline who will …the physicists have been getting away with it for years 😉

Luke (and his co-authors) argument is that abstraction can be dangerous (although of course it is also powerful).  It would be interesting perhaps rather than Wing’s paper to look at this argument alongside  Jeff Kramer’s 2007 CACM article “Is abstraction the key to computing?“, which I recall liking because it says computer scientists ought to know more mathematics 🙂 🙂

I also sadly missed some of Adrian Mackenzie‘s closing keynote … although this time not due to competing meetings but because I had been up since 4:30am reading a PhD thesis and after lunch on a Friday had begin to flag!  However, this was no reflection an Adrian’s talk and the bits I heard were fascinating looking at the way bio-tech is using the language of software engineering.  This sparked a debate relating back to the overuse of abstraction, especially in the case of the genome where interactions between parts are strong and so the software component analogy weak.  It also reminded me of yet another relatively recent paper3 on the way computation can be seen in many phenomena and should not be construed solely as a science of computers.

As well as the academic content it was great to be with the PPIG crowd they are a small but very welcoming and accepting community – I don’t recall anything but constructive and friendly debate … and next year they have PPIG09 in Limerick – PPIG and Guiness what could be better!

  1. David has done some really interesting work on the relationship between personality types and different kinds of programming tasks.  I’ve seen him present before about debugging and unfortunately had to miss his talk at PPIG on comprehension.  Given his work has has shown clearly that there are strong correlations between certain personality attributes and coding, it would be good to see more qualitative work investigating the nature of the differences.   I’d like to know whether strategies change between personality types: for example, between systematic debugging and more insight-based scan and see it bug finding. [back]
  2. but I can’t find on their website :-([back]
  3. Perhaps 2006/2007 in either CACM or Computer Journal, if anyone knows the one I mean please remind me![back]

Firefox 3 seems to have fixed memory problems

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I had been reluctantly considering giving up using Firefox as it crawled to a halt so often on so many sites. To be fair I think it is because I keep lots of tabs open and Firefox did not seem to deal will with pages with many refreshing elements … many air and train ticketing sites were particular problems. However, Firefox 3 has been running continuously for some time now and looking at ‘top’ in terminal window has about 1/3 the real memory footprint compared with Firefox 2 … now it is comparable with Word, Dreamweaver, etc. … I had been sticking with Firefox largely because the Firefox Snip!t bookmarklet works better than the Safari one, so now I can continue to do so without the machine crawling to a halt – well done team Mozilla 🙂

eprints: relaxed and scalable interfaces

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A story, a bit of a moan … and then I hope some constructive ideas .

It is time for the University annual report, which includes a list of all publications across the University. In previous years this was an easy job. I keep an up-to-date web page with all my publications for each year, so I simply gave our secretaries a link to the web publication list, they cut and paste it into Word, tidied the format a little … and job done. However, this year things are different … a short while ago the department installed an EPrints server. This year the department is making its submission to the University by downloading from the EPrints server, which means we have to upload to it :-/

The citation adding page runs to several screen fulls including breaking author names down into surname forename … the thought of that was somewhat daunting.

Fortunately you can import into EPrints from BibTeX and EndNote bibliographies … unfortunately mine is in plain HTML 🙁

Now the 10 million AKT project that Southampton was a lead partner in developed a free text bibliography server … but, unfortunately, not included in EPrints 🙁

So a few regular expression substitutions and a lot of hand edits later and I convert my 2007 pub list into BibTeX (actually couple of hours in total including ‘bug fixing’ syntax errors in the BibTeX).

Then upload the clean .bib file … beautiful – I get a list of all the uploaded items … but they are my ‘user workspace’ and not properly deposited. This I have to do one-by-one and not allowed to do so until I have filled in various additional fields, scattered liberally over several forms including one form for adding subjects that requires several clicks to open up a lovely tree browser that in the end has only 2 leaves.

Now after grouching the lessons.

There seems to be a few key problems:

(1) First the standard usability issues: the inclusion pages are oriented around the data in the system not the user, there are no shortcuts for previously entered authors, etc.

(2) The system will not allow data to be entered if it is not complete. Of course the institution wants full data (e.g. whether it is refereed, etc.), but making it difficult to enter data makes it likely that user will not bother. That is the alternative to perfect data may be no data!

(3) The interface to enter and edit is fine for a small number of entries, but becomes a pain when processing a complete publication list. Contrarily, the page for setting the subject categories is designed for handling large trees of categories but does not gracefully handle a small number.

Both (2) and (3) are also common problems, but not so well considred in usability iterature.

A useful inofmration systems heuristic that I often advocate is

“don’t enforce consistency, but highlight inconsistency”

In this case why not allow me to deposit incomplete records and then leave me a ‘to do list’ page … yes and maybe even badger me periodically with automatic emails to check it.

Anther maxim that applies to (2) is:

“Make it easy for the user to do what you want”

If you want people to upload references make it as easy as possible to do so. Now I’m sure the designers intend this to be the case, but it is easy sometimes to focus on usability of individual screens and interactions rather than the wider context.

In fact, this was the second time that I was faced with problem (3) today. Fiona had accidentally double clicked a large number of archived files when she was trying to drag them to Trash. She had to kill the application as it blindly started to open dozens of files (why not ask?). However, it was clearly coded resiliently and kept backup copies of the files it had started to open, so, when she tried to re-open it, InDesign started to ask her whether she wanted to recover the files … but did so one-by-one and wouldn’t let her do anything else until she had laboriously answered every dialogue box.

In this case the solution is fairly obvious, if there are many (or even ore than one) files to be recovered why not list them and aks about them all, perhaps with check boxes so you can recover some but not others. In general tabular or list-style views tend to work better with large numbers of items, allowing you to perform edits to many items in a single transaction.

Similarly in EPrints, after the import there were just a few fields required for each entry, some form of tabular view would have allowed me to scan down the link and select ‘refereed/not refereed’ for each entry.

With the subject categories, it was in a sense the opposite problem, but a symptom of the way we, as designers, often have some idea in out heads about how large a particular set is likely to be and then design around that idea. However, if you can notice this tendency one can often produce variant interaction styles depending on the size of the set. For example, in web-based systems to browse hierarchies I have often (but not always!) added code that effectively says, “if the number of entries at this level is not to great, then show this level as headings with the next level as well.”


fully expanded EPrints subjects menu

The EPrints server clearly expects that the subject tree will be far bigger, as it would be on a University-wide installation. Although even if the list is very large the number of items used by an individual would be small.

So as general design advice, if there is some form of collection:

  • are there any absolute lower or upper bounds on the size?
  • check, within these absolute bounds, what the interface would be like with 1, 3, 10, 100, 1000 in the collection
  • if the potential collection is large, is the likely size needed for a particular usre, situation, smaller?

To be fair I am an unusual user with my pretty complete HTML publication lists, if I had no systematic way of keeping my own publications then I would appreciate EPrints more. However, there will be many with word processor lists, so maybe I’m not so unusual. I assume other people just knuckle down and get on with it. So the real problem is that I am impatient user!

Which brings us to the last and most valuable piece of advice. When it comes to ussr testing cussed users are worth their weight in gold. Users that are too nice are useless,; they cope, they manage and would hate to hurt your feelings by telling you your system is not perfect. So find the nasty users, the impatient users, the ones who complain at the slightest things … they are true treasure.

escape from distraction

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Last week I was away in Cornwall and lost (but later found) my phone, so was both without a phone and with no internet connection … and it was amazingly liberating. My life is driven by the never ending stream of incoming mails and while in principle I could ignore them, in fact I find myself constantly breaking off what I do and seeing what has come in.

This reminded me of a Times article Haliyana pointed out to be a couple of weeks ago “Stoooopid …. why the Google generation isn’t as smart as it thinks“. We make a virtue of the never ending stream of interruptions that assail us; “multi-tasking” we call it, but in fact they not only mean we are less focused, but are possibly loosing the ability to concentrate at all.

While reading the article itself I found myself fighting not to want to follow the numerous links to other stories that littered the Times online page … and I would like to tell you more about it, but I never managed to read to the end before succumbing to the next interruption.

Basic Numeracy

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When the delayed SATS results eventually arrive, I’m sure there will be the regular navel gazing at the state of basic numeracy and literacy in UK schools. But what about those who were in primary schools 30 years ago?

This morning on BBC News Channel an interviewer was talking to an economist from the City. They were discussing the reduction in bank lending (a fall of 3% during June, with 32% year-on-year drop ) and its implications for the housing market and the economy in general. The interviewer asked if it was accelerating and the economist agreed, mentioning how the year-on-year drop had gone from 10% in one quarter to 20% in the next and now over 30%.

Of course these figures are all based on a year-on-year average that includes the period before the credit crunch began last autumn and in fact are consistent with a steady linear fall of around 3% per month for the 9 months since the Northern Rock collapse. That is an alarming rate of fall, but not evidence of an accelerating fall.

This apparent lack of basic numeracy reminds me of a discussion some years ago with senior financial executives who dismissed any attempt to quantify projected company income as ‘just numbers’. Having lost money in the Northern Rock collapse I wonder whether the executives in Northern Rock and other banks had a similar attitude!

I know it is easy for me as a trained mathematician to hold up my hands in horror, but still these are people who are playing not only with their own livelihoods, but also the lives of their investors, ordinary people and even the state of the entire economy.

We do have a peculiar attitude in the UK where it is acceptable for highly educated people (including many computer scientists) to just ‘not do math’, and furthermore say so with a level of pride, whereas to say the same about reading would be unconscionable. Other European countries seem far more numerate, so this seems to be a cultural phenomena not an intellectual problem.

I have heard that one of the best predictors of educational success is if a child is willing to put off a treat for another day. Mathematics does require doing work at one stage to see benefit maybe many years later, but this to some extent runs counter to the increasingly common expectation of students to want to know fully and completely how something is useful to them now.

Maybe the answer is for schools to have lessons in leaving sweeties until tomorrow … and perhaps remedial lessons for City economists who matured during the Thatcher years.

Thusly, he wrote

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Was with Kiel, one of my PhD students the other day, reading a draft chapter of his PhD thesis. He used the word ‘thusly’ and at first I thought this was a Kiel-ism (sorry Kiel, you do have a few). However, he assured me it was common usage … and not just for him. I suspected it was a regional idiom and indeed a bit of web searching finds many archaic uses of thusly, but several more recent Lancashire uses.

I suspect the word arose because ‘thus’ often precedes a verb and so has acquired an adverb ‘-ly’ ending … a form of lexical over-generalisation. … and if you have not already stopped reading because you can’t understand why anyone would be even interested in this level of language … as I did the web search found a lovely discussion site called INTERACTION (and no, this one is not the synonymous BCS HCI Group) where one person mildly mocked another for using ‘thusly’ in the 21st Century … obviously not a Lancashire lad.

This has also made me reflect on my own frequent use of ‘thus’ to mean ‘therefore’ as opposed to ‘in this way’ … argh am I really a grammar nerd :-/

why software need never hang

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Over 20 years ago I wrote “The Myth of the Infinitely Fast Machine“, about the way software developers effectively assume that everything on the machine side of human interaction happens instantly. Often interaction is programmed in a turn-taking style:

  1. wait for user action
  2. process the event
  3. display changes
  4. back to step 1

This assumption of instant (or at least infinitely fast) response at step 2 often ignores network delays, disk IO or heavy computation. This tends to work fine on a high-spec development or test machine, with a fast network and clean install of all system software … but when the software hits a real machine, a few years old, untidy system, slow network … things fall to pieces.

So 20 years later (as I described in my post last week) I am sitting watching the spinning rainbow ball as Word struggles to save a document (over an hour now, I think I will need to kill it). To be fair I think the root ’cause’ of the problem … or at least one problem … may be the printer as the Cannon printer driver has never worked properly on an Intel Mac (maybe new driver when I upgrade to Leopard?) and perhaps some change in the rest of the system (maybe the Office install) has tipped it over into not working at all.

As far as I can tell Word then decides to ask the printer things in order to set the margins properly when saving the document, and then gets stuck. I found a post on a Microsoft forum about a different print related problem and the ‘helpful’ tech support from MS simply said “not our fault, re-install everything”.

So to recap:

  • user asks Word to save – probably the most critical operation in the system, or the system auto-saves, again to ensure safety against crashes, so really critical
  • Word decides it needs information from the printer (although it has been displaying the page to the users using some existing information on page properties).
  • Word asks for info from the printer driver of the currently selected printer
  • if the printer doesn’t respond Word hangs and blocks all user interaction

However, the printer driver may be third party, may be connecting to a shared printer hanging off a different network, or in the case of a laptop on a network currently disconnected from the computer … and any resulting delay is not the fault of the developers of Word??!

The annoying thing is that such ‘hanging’ delays need never happen.

Basically there are four main causes for delays:

  1. ordinary computation takes a long time due to it being too complex for the available hardware
  2. unbounded internal computation -for example iterative algorithms
  3. waiting for external resources (disk, network, etc.)
  4. bugs that lead to the system going crazy (effectively case 2 by accident!)

Type 1 will surface during testing and may require re-design of the interaction, but is simply ‘slow’ rather than ‘hanging’. Typically it leads to things gradually getting slower as the document or data gets larger or more complicated. This requires standard profiling and optimisation.

Type 4 is hard to deal with – bugs do happen. However, the majority of the problems I’m experiencing in Word at the moment are not a failure of this kind as Word does, most of the time, eventually complete without crashing.

Types 2 and 3, especially the latter, should be detected and then dealt with in the design of the user interface.

Some real-time programming languages have ways of automatically working out how long code will take to run in order to be able to assert “this will respond within a 10 ms interrupt cycle”. However, this is hard, even for relatively simple embedded systems; so not practical for complex operating systems or user interfaces.

However, a simpler version of the above is possible. Certain system functions invoke external resources such as the disk, or the network. If any function or method in your own application invokes one of these system functions, then it could potentially hang – and should be documented to say so or return some sort of ‘promise’: “I’ve started to do X, please check back later to see if it is ready”. Of course the methods that call these themselves need to be documented as potentially hanging … and so forth.

If the response to any form of user interaction ends up calling a potentially hanging function, then it is in danger of having a delay of type 3 above. However, so long as this is known, it can be dealt with at the user interface level by spawning a thread to do the work so that some form of progress indicator or at least “Cancel” button can be active – it should never ‘hang’.

This marking of functions as potentially ‘hanging’ could be done by programmers themselves, but equally can be automated as a form of static analysis, simply starting with a known set of hanging system functions and recursively ‘colouring’ functions that call them. This kind of automated checking should be standard practice in any large software project.

The type 2 hanging is a little more complicated. The ADA programming language has a ‘safe’ subset that only allows loops where the bounds are fixed at compile time. This is probably too restrictive for complex software, but certainly any loop with unknown limits could be flagged. If as part of a code walk through or similar practice it is decided that the loop is ‘safe’ it can be annotated as such, otherwise, just like the case of system calls, the system can propagate the fact that certain functions may have unbounded computation and then the UI adjusted accordingly.

For small bespoke software development I can be forgiving, but for large vendors like Microsoft, Apple or Adobe, there is no excuse for this form of culpable failure.

… but I have a bad feeling that in 20 years time I may be writing again …

[[ News flash – 1.5 hours later Word has finished saving the document! … 14 pages obviously hard work. … but then it has hung again 🙁 ]]