July 8, 2016
Episode 3 in a series “Things that are the way they are because of constraints that no longer apply” (or: why we don’t change processes we have invested in that don’t make sense any more)
The standard railway gauge (that is, the distance between train rails) for over half of the world’s railways (including the USA and UK) is 4′ 8.5″, or 1.435m. While a few other railway gauges are in common use, including, to my surprise, in Ireland, where the gauge is 5′ 3″, or 1.6m. If you’re like me, you’ve wondered where these strange numbers came from.
Your first guess might be that, similar to the QWERTY keyboard, it comes from the inventor of the first train, or the first successful commercial railway, and that there was simply no good reason to change it once the investment had been made in thbat first venture, in the interests of interoperability. There is some truth to this, as railways were first used in coal mines to extract coal by horse-drawn carriages, and in the English coal mines of the North East, the “standard” gauge of 4′ 8″ was used. When George Stephenson started his seminal work on the development of the first commercial railway and the invention of the Stephenson Rocket steam locomotive, his experience from the English coal mines led him to adopt this gauge of 4′ 8″. To allow for some wiggle room so that the train and carriages could more easily go around bends, he increased the gauge to 4′ 8.5″.
But why was the standard gauge for horse-drawn carriages 4′ 8″? The first horse-drawn trams used the same gauge, and all of their tools were calibrated for that width. That’s because most wagons, built with the same tools, had that gauge at the time. But where did it come from in the first place? One popular theory, which I like even if Snopes says it’s probably false, is that the gauge was the standard width of horse-drawn carriages all the way back to Roman times. The 4′ 8.5″ gauge roughly matches the width required to comfortably accommodate a horse pulling a carriage, and has persisted well beyond the end of that constraint.
July 7, 2016
Episode 2 in a series “Things that are the way they are because of constraints that no longer apply” (or: why we don’t change processes we have invested in that don’t make sense any more)
American or English computer users are familiar with the QWERTY keyboard layout – which takes its name from the layout of letters on the first row of the traditional us and en_gb keyboard layouts. There are other common layouts in other countries, mostly tweaks to this format like AZERTY (in France) or QWERTZ (in Germany). There are also non-QWERTY related keyboard layouts like Dvorak, designed to allow increased typing speed, but which have never really gained widespread adoption. But where does the QWERTY layout come from?
The layout was first introduced with the Remington no. 1 typewriter (AKA the Scholes and Glidden typewriter) in 1874. The typewriter had a set of typebars which would strike the page with a single character, and these were arranged around a circular “basket”. The page was then moved laterally by one letter-width, ready for the next keystrike. The first attempt laid out the keys in alphabetical order, in two rows, like a piano keyboard. Unfortunately, this mechanical system had some issues – if two typebars situated close together were struck in rapid succession, they would occasionally jam the mechanism. To avoid this issue, common bigrams were distributed around the circle, to minimise the risk of jams.
The keyboard layout was directly related to the layout of typebars around the basket, since the keyboard was purely mechanical – pushing a key activated a lever system to swing out the correct typebar. As a result, the keyboard layout the company settled on, after much trial and error, had the familiar QWERTY layout we use today. At this point, too much is invested in everything from touch-type lessons and sunk costs of the population who have already learned to type for any other keyboard format to become viable, even though the original constraint which led to this format obviously no longer applies.
Edit: A commenter pointed me to an article on The Atlantic called “The Lies You’ve Been Told About the QWERTY Keyboard” which suggests an alternate theory. The layout changed to better serve the earliest users of the new typewriter, morse code transcribing telegraph operators. A fascinating lesson in listening to your early users, for sure, but also perhaps a warning on imposing early-user requirements on later adopters?
June 5, 2016
Episode 1 in a series “Things that are the way they are because of constraints that no longer apply” (or: why we don’t change processes we have invested in that don’t make sense any more)
I posted a brief description of the Five Monkey experiment a few days ago, as an introduction to a series someone suggested to me as I was telling stories of how certain things came about> One of the stories was about school Summer vacation. Many educators these days feel for the most part that school holidays are too long, and that kids lose knowledge due to atrophy during the Summer months – the phenomenon even has a name. And yet attempts to restructure the school year are strongly resisted, because of the amount of investment we have as a society in the school rhythms. But, why do US schools have 10-12 weeks of Summer vacation at all?
The story I had heard is that the Summer holiday is as long as it is, because at the origins of the modern education system, in a more agrarian society, kids were needed on the farm during the harvest and could not attend school.I do like to be accurate when talking about history, and so I went reading, and it turns out that this explanation is mostly a myth – at least in the US. And, as a farmer’s kid, that mostly makes sense to me. The harvest is mostly from August through to the beginning of October, so starting school in September, one of the busiest farming months, does not make a ton of sense.
But there is a grain of truth to it – in the US in the 1800s, there were typically two different school rhythms, depending on whether you lived in town or in the country. In town, schools were open all year round, but many children did not go all of the time. In the country, schools were mainly in session during two periods – Winter and Summer. Spring, when crops are plated, and Autumn, when they are harvested, were the busy months, and schools were closed. The advent of compulsory schooling brought the need to standardise the school year, and so vacations were introduced in the cities, and restructured in the country, to what we see today. This was essentially a compromise, and the long Summer vacation was driven, as you might expect, by the growing middle class’s desire to take Summer holidays with their children, not the farming family’s desire to exploit child labour. It was also the hardest period of the year for children in cities, with no air conditioning to keep school classrooms cool during the hottest months of the year.
So, while there is a grain of truth (holidays were scheduled around the harvest initially), the main driver for long Summer holidays is the same as today – parents want holidays too. The absence of air conditioning in schools would have been a distant second.
This article is US centric, but I have also seen this subject debated in France, where the tourism industry has strongly opposed changes to the school year structure, and in Ireland, where we had 8-9 weeks vacation in primary school. So – not off to a very good start, then!
June 3, 2016
The (probably apocryphal) five monkeys experiment goes like this:
Five monkeys are placed in a cage. There is a lever, which, if pulled, delivers food. The monkeys soon learn how it works, and regularly pull the level.
One day, when the lever is pulled, food is still delivered to the puller, but all the monkeys in the cage get an ice-cold shower for a period of time. The monkeys quickly learn the correlation between the lever and the cold shower, and stop any monkey from getting to the lever.
After a while, one of the monkeys is removed, and replaced by a new monkey. Out of curiosity, the new monkey tried to pull the lever, and was beaten into submission by the other monkeys. Progressively, more of the original five monkeys are removed, and replaced with new monkeys, and they all learn the social rule – if you try to pull the lever, the group will stop you.
Eventually, all of the original monkeys are gone. At this point, you can turn off the shower, secure in the knowledge that none of the monkeys will pull the lever, without ever knowing what will happen if they do.
A funny anecdote, right? A lesson for anyone who ever thinks “because that’s the way it has always been”.
And yet, there are a significant number of things in modern society that are the way they are because at one point in time, there was some constraint that applied, which no longer applies in the world of air travel and computers. I got thinking about this because of the electoral college and the constitutional delays between the November election and the January inauguration of a new president – a system that exists to get around the logistical constraints of having to travelling distances on horseback. But that is far from the only example.
I hope to write a series, covering each of the examples I have found, and hopefully uncovering others along the way, and the electoral college will be one of them. First up, though, will be the Summer school vacation.
March 4, 2016
The US presidential primaries
For those following the US presidential primaries from a distance, and wondering what is happening, here’s a brief dummies’ guide to the US presidential primaries and general election. It’s too early to say that Trump has won the Republican primary yet, even though (given his results and the media narrative) he is a strong favourite. To learn more than you will ever need to know about US presidential primaries, read on.
Primaries elect delegates
The presidential candidates are elected by the major parties at their party conventions, held during the Summer before the election. The primary elections are one way that the parties decide who gets to vote in the convention, and who they vote for.
Both parties have the concept of pledged and unpledged delegates – if you are pledged, then your vote in the 1st ballot of the nomination election has been decided in the primary. If you are unpledged, then you are free to change vote at any time. The Democrats have about 15% of their delegates unpledged, these are called superdelegates. The Republican party has about 170 unpledged delegates, representing about 7% of the total delegate count. Each state decides how to award pledged delegates, with a variety of processes which I will describe later.
If no candidate has a majority of delegated on the 1st ballot, then the fun starts – delegates are free to change their affiliation for 2nd and further ballots. This scenario, which used to happen often but now happens rarely, is called a contested or brokered convention. The last brokered convention was in 1952 for the Democrats, and 1948 for the Republicans. We have come close on a number of occasions, most recently 2008 for the Democrats, and 1976 for the Republicans.
Read the rest…
February 23, 2016
Comments Off on Targeted selection for job interviews
A post by Amanda McPherson about her best interviewing tip over on LinkedIn got me thinking about an interview technique I was taught while on the GNOME board many years ago:
Focus on behavior. In jobs related to product management, business development, sales, marketing or communications, you have people who are verbally skilled. Ask them anything and you will likely get a good verbal response, but that doesn’t mean it’s true. Focusing on behavior — how they follow up, how and when they respond to your emails and questions, how they treat you vs others on the team for instance — yields more accurate data of how they will be on a daily basis.
She quotes the story of a Charles Schwab executive who would take candidates to breakfast interviews, and ask the restaurant to mix up the order deliberately – just to see how they would react to the stressful event.
The technique, which was taught to the GNOME board by Jonathan Blandford, goes one step further. The principle of targeted selection is that the best predictor of future behaviour is past behaviour. So if you are hiring someone to manage a team, ask about a time they were a manager in the past. If you need someone who can learn quickly in a new and fast moving domain, ask them about a time they were in a similar situation. Then dig deep for details – what did they do, how did they interact with others, how effective was the outcome of the situation?
As an example: if you want to know how someone reacts under pressure, ask about a time that they were working on a project that ran late. Ask them to describe the moment when they realised that they were not going to make the release date on time, on quality, as planned. Then ask how they reacted – did they reduce scope, fight for a schedule extension, add people, get everyone working weekends? Was there a post mortem after the project shipped? Who took the lead on that? How were the lessons applied in the next project? You can use a line of questioning like this to identify the people who will power through obstacles, regardless of the cost; people who are more consensual, but may lack decisiveness; people who seek help versus taking on too much burden. This type of insight is gold-dust when you are evaluating a candidate.
Some other ideas for questions:
- If you want someone who can ramp up quickly in a new area, ask about the last technology they discovered and became expert on. Then ask about the early days – was their instinct to read blogs, books, tutorials? To follow practical labs? To pay for training? Did they seek out people to ask questions and share knowledge? How did they evaluate where they were in the learning process? Have they stayed active and learning, or did they stop once they had enough knowledge to do the job? There is no right answer, but the approach they took will give you an idea of how they would attack a similar challenge in the future.
- If inter-personal relationships are key to success in the job, dig into a time they had a significant disagreement (with a boss, with a subordinate, with a colleague, with someone in a community project) – something meaningful and important to them. How did they go about arguing their case? Was winning more important than getting a good solution? How important was the relationship to them?
- If organisational skills are key: ask for an example of a time when they had to clean up after someone else. How did they go about draining the swamp? What do they say about the former organiser? How did they balance organising the existing system with allowing people to interact with the system and continue doing their jobs?
It isn’t just prospective employers who can use this technique to have better interviews. For candidates, this method can be awesome to allow you to prepare and take ownership of an interview. Look at the job requirements and required experience. When were you in a situation when you got to show the skills required? What were your actions, and what were the results?You can tell a story about your experience that hits all of the job requirements, even if your interviewer is not asking questions about it.
Go one step further: interview your interviewer! Think about the situations in the past where you have been successful and unsuccessful, and come up with your requirements – take that knowledge into the interview, and ask questions to check whether the position is a good match for you. Interviews are a two-way street, and you are interviewing the company as much as they are interviewing you. Ask interviewers when they were confronted with certain situations, and dig into their experiences as employees of the company. Is this a company that expects you to work weekends to meet unrealistic deadlines? Are you thrown a life buoy and expected to sink or swim? Is there a strict hierarchical structure, or are everyone’s perspectives heard and respected? Is there mobility within the company, or do people hit a developmental ceiling?
The great thing about this line of questioning is that it is not accessing the hypothetical side of the brain – you are not getting the idealised “I would…” answer where infinite time and resources, and everyone’s buy-in can be assumed. You are accessing memory banks, and the more details you get, the closer you get to the truth of how the person reacts. Especially great for providing insights are trade-offs, where there is no right answer – when two people want different things and you are there to adjudicate or be the intermediary, when you have to choose between two top priorities, when you only have enough time to do one of the three things that are important. In situations like that, you can really get insight into the approach and mentality of candidates, and also help candidates judge the culture and priorities of a company.
November 24, 2015
Comments Off on SDN/NFV DevRoom at FOSDEM: Deadline approaching!
We extended the deadline for the SDN/NFV DevRoom at FOSDEM to Wednesday, November 25th recently – and we now have the makings of a great line-up!
To date, I have received proposals about open source VNFs, dataplane acceleration and accelerated virtual switching, an overview of routing on the internet that looks fascinating, open switch design and operating systems, traffic generation and testing, and network overlays.
I am still interested in having a few more NFV focussed presentations, and one or two additional SDN controller projects – and any other topics you might think would tickle our fancy! Just over 24 hours until the deadline.
April 30, 2015
Comments Off on 5 Humanitarian FOSS projects
Over on opensource.com, I just posted an article on 5 humanitarian FOSS projects to watch, another instalment in the humanitarian FOSS series the site is running. The article covers worthy projects Literacy Bridge, Sahana, HOT, HRDAG and FrontlineSMS.
A few months ago, we profiled open source projects working to make the world a better place. In this new installment, we present some more humanitarian open source projects to inspire you.
April 17, 2014
Comments Off on Writing more
I realised recently that most of my writing has been of the 140 character format recently…. I plan to rectify this, starting today.
February 11, 2014
There are times in a long career when you have to turn your back on what’s gone before. In work, this is easy. People stop giving you a paycheck, you stop turning up to work. And yet, some of my best friends are people I worked with 10 years ago.
In open source, it’s harder. You build relationships, you grow emotional attachments to projects you work on.
When life moves you on from a project, you stay subscribed to mailing lists, you add mail filters to move them to a folder you read less and less frequently.
When you hit a threshold where you no longer consider yourself a developer or contributor, you keep watching from afar, and when the project takes a direction you disagree with, that you know you would have argued against, you feel a little sadness.
After a while, this build-up of guilt weighs you down. But letting go is hard to do.
I’m learning. Trying to get better at letting go. The next generation needs to find their own way. It’s liberating and saddening in equal measure. Old friends: we will stay friends, but I need to trust you to make your own way.
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