The C Standard

is an excellent book (isbn 0-470-84573-2). As usual I'm going to quote from a few pages:
Except when it is the operand of the sizeof operator, the unary & operator, the ++ operator, the -- operator, or the left operand of the . operator or an assignment operator an value that does not have an array type is converted to the value stored in the designated object (and is no longer an lvalue). ( Lvalues, arrays, and function designators)
object: region of data storage in the execution environment, the contents of which can represent values. (3.14 Terms, definitions, and symbols)
Between the previous and next sequence points an object shall have its stored value modified at most once by the evaluation of an expression. (6.5 Expressions)
At certain specified sequence points, al side effects of previous evaluations shall be complete and no side effects of subsequent evaluations shall have taken place. ( Program execution)
If a "shall" or "shall not" requirement that appears outside of a constraint is violated, the behaviour is undefined. (4. Conformance)
A conforming program is one that is acceptable to a conforming implementation. (4. Conformance)
implementation: particular set of software, running in a particular translation environment under particular control options, that performs translation of programs for, and supports execution of functions in, a particular execution environment. (3.12 Terms, definitions, and symbols)
A full expression is an expression that is not part of another expression or declarator… The end of a full expression is a sequence point. (6.8 Statements and blocks)

The Pragmatic Programmer

is an excellent book by Andrew Hunt and Dave Thomas (isbn 0-201-61622-X). As usual I'm going to quote from a few pages:
A very simple but particularly effective technique for finding the cause of a problem is simply to explain it to someone else.
Fred doesn't know why the code is failing because he didn't know why it worked in the first place.
Chips are designed to be tested.
Design to Test.
Abstractions live longer than details.
Some things are better done than described.
Don't give in to the false authority of a method.
Test Early. Test Often. Test Automatically.
Organize around functionality, not job functions.
When woodworkers begin a project, they cut the longest pieces first, then cut the smaller pieces out of the remaining wood.
The Law of Demeter for functions states that any method of an object should call only methods belonging to: itself, any parameters that were passed in to the method, any objects it creates, and directly held component objects.


I've been thinking about courage. Scott Peck writes:

The absence of fear is not courage; the absence of fear is some kind of brain damage. Courage is the capacity to go ahead in spite of fear, or in spite of pain.

Courage is one of the 4 values of eXtreme Programming. I was struck by how every mention of courage in Kent's book, and also during a short googling session, has a technical rather than a social slant to it:

  • Communication supports courage because it opens the possibility for more high-risk, high-reward experiments...
  • Simplicity supports courage because you can afford to be much more courageous with a simple system...
  • Concrete feedback supports courage because you feel much safer trying radical surgery on the code if you can push a button and see tests turn green at the end (or not, in which case you can throw the code away).

It's sometimes said that Scrum is very good at surfacing problems, making problems visible, and that if we don't deal with these problems it's not Scrum that's failed it's us. Moments of social tension are exactly like that. Tension surfaces, is felt, but isn't held and openly dealt with, and so slowly sinks out of view.

Problems in software are always a mixture of the technical and the social. I think many developers find it relatively easy to be technically courageous but not so easy to be socially courageous. Being technically courageous but not socially courageous is solving the symptoms but not the root-causes. In every case, if you fail to deal with the underlying causes you create a bad self-fulfilling dynamic.

Courage relates to trust. Holding the issue and not letting it sink away feels risky. But if you never take any risks you're not likely to create any trust. Acting when you feel a little scared is what courage is.

Courage relates to congruence. Congruence is about alignment. If you feel X, it's ok to say that you feel X, to sound like you feel X, and to look like you feel X.

Moments of fear can be precious moments. They can become moments of courage.

My Kanban 1s Game

Update! I've now created a Kanban Board Game around this idea.

Here's the latest slide-deck for my kanban 1s game. Based on feedback from several recent sessions I've changed two features:
  • Backlog It now costs 1 unit of work to create a backlog item. Also a worker on any table can create a backlog item at any time.
  • Bugs There's now a much simpler way of simulating bugs - simply lose all the current work on the story-card.
Jon Jagger's Kanban 1s Game

extreme Programming explained

is an excellent book by Kent Beck (isbn 0-201-61641-6). As usual I'm going to quote from a few pages:
Without courage, XP just simply doesn't work.
Communication supports courage because it opens the possibility for more high-risk, high-reward experiments… Simplicity supports courage because you can afford to be much more courageous with a simple system… Concrete feedback supports courage because you feel much safer trying radical surgery on the code if you can push a button and see tests turn green at the end (or not, in which case you can throw the code away).
Pair programming works for XP because it encourages communication… In my experience, pair programming is more productive than dividing the work between two programmers and then integrating the results.
If people program solo they are more likely to make mistakes, more likely to overdesign, and more likely to blow off the other practises, particularly under pressure.
There are times when problems simply can't be solved by the emergent brilliance of the team, encouraged by a loving and watchful manager. At times like this, the XP manager must be comfortable stepping in, making decisions - even unpopular ones - and seeing the consequences through to the end.
XP is a communal software development discipline.
The best environment is one of mutual trust.
Under stress, people revert to earlier behaviour, no matter how badly that behaviour has worked in the past.
Today's design should be done today and tomorrow's design should be done tomorrow.
Nerds aren't generally good at talking.
When you say one thing and do another, bad things happen. This book [Gerald Weinberg, Quality Software Management: Volume 4(sic), Congruent Action] talks about how to be congruent yourself, how to recognise incongruence in others, and what to do about it.

The Trusted Advisor

is an excellent book by David Maister, Charles Green, and Robert Galford (isbn 978-0-7432-0776-8). As usual I'm going to quote from a few pages:
Trust frees us from the need to spend time on inconsequential projects or tedious procedural issues.
You must be willing to give in order to get.
Creating trust entails taking some personal risks. It is the essence of trust. If you're not a little scared on occasion, then you're not taking a risk. And if you're not taking a risk, you're not likely to create trust.
Trust is personal… "institutional trust" is an oxymoron.
It is not enough for a professional to be right: An advisor's job is to be helpful.
…they are, above all, looking for someone who will provide reassurance, calm their fears, and inspire confidence.
Excellence in advice giving requires not only the right attitude, but also a careful attention to language.
"I was amazed at how many fools I ran into until I noticed the common denominator in all those interactions: me."
Trust = (Credibility + Reliability + Intimacy) / Self Orientation
Reliability in this largely rational sense is the repeated experience of links between promises and action… Reliability in this emotional sense is the repeated experience of expectations fulfilled.
The most common failure in building trust is the lack of intimacy… Greater intimacy means that fewer subjects are barred from discussion.
The purpose of listening in building trust is to earn the right to engage in a mutual exploration of ideas.
Effective trusted advisors are very good listeners.

DaVinci Decoded

is an excellent book by Michael Gelb (isbn 0-385-33861-9). As usual I'm going to quote from a few pages:
Ritual is the husk of true faith [Lao Tzu]
Poor is the man who desires many things. Neither promise yourself things nor do things if you see that when deprived of them they will cause you material suffering. [Leonardo]
He prided himself on being a uomo sense letter (man without academic training) and a disciepolo della sperienza (disciple of experience).
I shall continue. I never tire of being useful. Obstacles do not bend me. Every obstacle is destroyed through rigour. [Leonardo]
You can have neither greater nor lesser dominion than you have over yourself. [Leonardo]
The average person "looks without seeing, listens without hearing, touches without feeling, eats without tasting, moves without physical awareness, inhales without awareness of odour or fragrance, and talks without thinking." [Leonardo]
Mindfulness is complete attention in the now, rather than worrying about the past or investing in expectations about the future.
The Jewish tradition, for example, teaches that "the key to everything is the way you start."
Fill the space with objects and images that inspire you to remember your connection to something greater than your own ego.
In his anatomical studies, as in everything else he did, Leonardo was always striving for the most all-encompassing type of understanding as well as the most detailed.
Leonardo himself was known to be even-tempered and optimistic, even when life was hard. He was also meticulous in his daily habits of eating, exercising, and resting.
Modern research confirms ambidexterity promotes balance and brain development. Not surprisingly, Leonardo was ambidextrous.

Wisdom of the idiots

is an excellent book by Idries Shah (isbn 0-86304-046-2). As usual I'm going to quote from a few pages:
Different modes of behaviour on the part of the wise are to be regarded as due to differences in individuality, not of quality.
Only stupid people and pedants imagine that their duty is to instruct everyone, when the motive of the people is generally not to seek instruction, but to attract attention.
Words alone do not communicate: there must be something prepared, of which the words are a hint.
When you have found yourself you can have knowledge. Until then you can only have opinions. Opinions are based on habit and what you conceive to be convenient to you. The study of the Way requires self-encounter along the way.
…people spend most of their time either jumping to conclusions or else taking no notice at all of facts.
Perception without wisdom is worse than nothing at all.
How much of my life is being wasted while I wait for someone to tell me what to do or something to happen which will change my condition and frame of mind?
'Alas', said the Sufi, 'there was only one thing wrong with your attempt to apply Sufi methods. You were not a Sufi.'
The assumption that anyone of worth can explain himself fully and lucidly in the time allotted him by those who want to learn what he knows - is either a joke or a stupidity.
It is learnt by means of practice. If you cannot practice it, you cannot learn it. If you cannot learn it, you do not really want to learn it inwardly at all.
A crooked plan will benefit only the crooked, a wise one only the wise.

Wooden on Leadership

is an excellent book by John Wooden and Steve Jamison (isbn 978-0-07-145339-4). As usual I'm going to quote from a few pages:
Effort is the ultimate measure of your success.
I believe leadership itself is largely learned.
In the end, the choice you make makes you.
Genius is nothing but a greater aptitude for patience. [Benjamin Franklin]
Sometimes during practice he would have the guards switch positions with the forwards - have us do the other guy's job. He wanted everybody to understand the requirements of the players in the other position… I was so impressed by the control of his practice. [Gail Goodrich]
There are no big things, only an accumulation of many little things.
What happened is a good lesson in how we can limit ourselves and our organisations without even knowing it - how we can say "no" when we should be asking "how?"
Success breeds satisfaction; satisfaction breeds failure.
Lots of repetition. You can't believe the repetition. [Gary Cunningham]
Things turn out best for those who make the best of how things turn out.
I rarely assigned one player to a basket. Basketball is a team sport, and I felt it was unwise to allow players to practice by themselves. Always I wanted them to be interacting with their teammates.
How you practice is how you "play"… It's only natural for those under your leadership - perhaps even you - to focus on the end result rather than learning and doing what it takes to get there. I attempted to solve this particular problem at UCLA by occasionally removing the siren song; specifically, I made them practice and play basketball without the ball.
A good leader always seeks improvement - always.

Measuring and managing performance in organizations

is an excellent book by Robert Austin (isbn 978-0-932633-36-1). As usual I'm going to quote from a few pages:
When outcomes are revealed so slowly, learning is difficult.
The difficulty of verifying quality is heightened when production activity is largely mental, hence not directly observable, as in many professional settings such as software development.
Empirical work on human motivation (Frey, 1993; Deci and Ryan, 1985, McGraw, 1978) has shown that external motivators often crowd out internal motivation.
Alfie Kohn (1993) observes that measurement connotes comparability which, in turn, fosters competition and even unfriendly feeling between workers, thereby undermining any sense of common purpose.
You manage things, and you lead people. You control things, and you release people. [Ed Tilford]
There is reason to question whether the two intended uses of measurement [motivation and information] can be decoupled in real settings.
W. Edwards Deming, often considered the father of both the Japanese and the American quality movements, has declared performance measurement "the most powerful inhibitor to quality and productivity in the Western world".
Dysfunction's defining characteristic is that the actions leading to it fulfil the letter but not the spirit of stated intentions.
Measured performance trends upward; true performance declines sharply. In this way, the measurement system becomes dysfunctional.
…conclude that no measurement system can be designed to preclude dysfunctional behaviours.
…motivational measurement is, by definition, intended to cause reactions in the people being measured, while informational measurement should be careful not to change the actions of the people being measured.
Russell Ackoff draws a careful distinction between organisms and organisations (concisely paraphrased here by Mason and Swanson): … organisms are comprised of organs that only serve the purpose of the system, whereas organisations are comprised of purposeful subsystems with their own goals.
The quality of a product or service is usually much harder and costlier to measure than its quantity.
If there is a single message that comes from this book, it is that trust, honesty, and good intention are more efficient in many social contexts than verification, guile, and self-interest.
The inclination to interpret control narrowly is due to what might be called a standardisation reflex.
Engineering control does not ordinarily assume self-interested behaviour on the part of components of the control system.
Almost all experts strongly agreed that the primary reason to measure in software development was informational rather than motivational.

do more deliberate practice

This is one of my entries in 97 Things Every Programmer Should Know

Deliberate practice is not simply performing a task. If you ask yourself "Why am I performing this task?" and your answer is "To complete the task," then you're not doing deliberate practice.

You do deliberate practice to improve your ability to perform a task. It's about skill and technique. Deliberate practice means repetition. It means performing the task with the aim of increasing your mastery of one or more aspects of the task. It means repeating the repetition. Slowly, over and over again. Until you achieve your desired level of mastery. You do deliberate practice to master the task not to complete the task.

The principal aim of paid development is to finish a product whereas the principal aim of deliberate practice is to improve your performance. They are not the same. Ask yourself, how much of your time do you spend developing someone else's product? How much developing yourself?

How much deliberate practice does it take to acquire expertise?
  • Peter Norvig writes that "It may be that 10,000 hours [...] is the magic number."
  • In Leading Lean Software Development Mary Poppendieck notes that "It takes elite performers a minimum of 10,000 hours of deliberate focused practice to become experts."
The expertise arrives gradually over time — not all at once in the 10,000th hour! Nevertheless, 10,000 hours is a lot: about 20 hours per week for 10 years. Given this level of commitment you might be worrying that you're just not expert material. You are. Greatness is largely a matter of conscious choice. Your choice. Research over the last two decades has shown the main factor in acquiring expertise is time spent doing deliberate practice. Innate ability is not the main factor.
  • Mary: "There is broad consensus among researchers of expert performance that inborn talent does not account for much more than a threshold; you have to have a minimum amount of natural ability to get started in a sport or profession. After that, the people who excel are the ones who work the hardest."
There is little point deliberately practicing something you are already an expert at. Deliberate practice means practicing something you are not good at.
  • Peter: "The key [to developing expertise] is deliberative practice: not just doing it again and again, but challenging yourself with a task that is just beyond your current ability, trying it, analyzing your performance while and after doing it, and correcting any mistakes."
  • Mary: "Deliberate practice does not mean doing what you are good at; it means challenging yourself, doing what you are not good at. So it's not necessarily fun."
Deliberate practice is about learning. About learning that changes you; learning that changes your behavior. Good luck.

This blog entry is "syndicated" in Croatia on

Toyota kata

is an excellent book by Mike Rother (isbn 978-0-07-163523-3). As usual I'm going to quote from a few pages:
As the field of psychology shows us, with practice, behaviour patterns are changeable, learnable, and reproducible.
The improvement kata does not come to life in an organisation simply because it is a good idea.
In many cases the normal operating condition of an organisation - its nature - is not improving.
A process will tend to erode no matter what… A process is either slipping back or being improved, and the best and perhaps only way to prevent slipping back is to keep trying to move forward, even if only in small steps.
Ideally we would utilise the human intellect of everyone in the organisation to move it beyond forces of natural selection and make it consciously adaptive… At Toyota, improvement and adaptation are systematic and the method is a fundamental component of every task performed, not an add-on or a special initiative.
At Toyota, improving and managing are one and the same.
Systems theory tells us that we cannot optimise a system by trying to maximise its individual parts.
If the prevailing philosophy is to "make production", then the first process with four operators seems preferable. This process can work around problems and still make the target output, which is why you find this kind of arrangement on so many shop floors. On the other hand, at Toyota this sort of flexibility is considered negative, since problems go unresolved and the process gets into a nonimproving, firefighting cycle… A 1x1 is not just part of the ideal state condition, it is also a means for helping to get there.
The "Forrester effect"… any unevenness in assembly is increasingly amplified as the demand is transmitted to upstream processes.
Just introducing a kanban system by itself will improve very little; the system only mirrors and sheds light on the current situation.
Engineers, for example, often try to define target conditions in terms of solutions… You have to learn to hold yourself back and first define where you want to go before you get started on moving there.
It matters more that you take a step than what the first step is.
What we are actually doing with a plan is making a prediction.
We learn from failures because they reveal boundaries in our system's current capability and horizons in our minds.
Thinking that an abnormality or problem is neither positive or negative shifts the focus from the individual to the process.
Consider for example, the dieting quote, "I got fat slowly, then suddenly."
It is not possible to objectively assess one's own performance and see what skills you need to work on.
Observe, don't interview.
Everyone at Toyota has a mentor.
An organisation's intentionally cultivated behaviour patterns are a fragile thing.
You cannot reorganise your way to continuous improvement and adaptiveness… It surprises many people, in fact, to find that Toyota is largely organised in a traditional, functional-department style…Repeated practice - conditioning - creates neural pathways and, over time, an organisation's culture.
What is your improvement kata?

97 things every programmer should know

is an excellent book edited by Kevlin Henney (isbn 978-0-596-80948-5). As usual I'm going to quote from a few pages:
Pay off technical debt as soon as possible. It would be imprudent to do otherwise. Seb Rose
Users don't think like programmers. Giles Colborne
Comment what the code cannot say, not simply what it does not say. Kevlin Henney
Deliberate practice is not simply performing a task. If you ask yourself "Why am I performing this task?" and your answer is "To complete the task," then you're not doing deliberate practice. Jon Jagger
the Golden Rule of API Design: It's not enough to write tests for an API you develop; you have to write unit tests for code that uses your API. Michael Feathers
Professional programming is usually not like running hard for a few kilometres, where the goal can be seen at the end of a paved road. Most software projects are more like a long orienteering marathon. In the dark. With only a sketchy map as guidance. Olve Maudal
What are you working on right now? Is it all needed? Pete Goodliffe
By making sure that the build is always clean, I will not have to decide that a warning is irrelevant every time I encounter it. Ignoring things is mental work, and I need to get rid of all the unnecessary mental work I can. Johannes Brodwall
An estimate is an approximate calculation or judgement of the value, number, quantity, or extent of something… A target is a statement of a desirable business objective… A commitment is a promise to deliver specified functionality at a certain level of quality by a certain date or event… Giovanni Asproni
If your project is apparently on track, and one week later it's six months late, you have problems - the biggest of which is probably not that it's six months late, but the invisibility force fields powerful enough to hide six months of lateness! Lack of visible progress is synonymous with lack of progress. Jon Jagger
Sometimes the best thing you can do to solve a problem is to put the mouse down and step away from the keyboard. Burt Hufnagel
The Singleton Pattern… What's not to like about this classic design pattern? Quite a lot, it turns out. Sam Saariste