Archive for November 2012

Why so many features?

 

It is a frequent complaint that production software contains too many features: “I use only  maybe 5% of Microsoft Word!” , with the implication that the other 95% are useless, and apparently without the consideration that maybe someone else needs them; how do you know that what is good enough for you is good enough for everyone?

The agile literature frequently makes this complaint against “software bloat“, and has turned it into a principle: build minimal software.

Is software really bloated? Rather than trying to answer this question it is useful to analyze where features come from. In my experience there are three sources: internal ideas; suggestions from the field; needs of key customers.

1. Internal ideas

A software system is always devised by a person or group, who have their own views of what it should offer. Many of the more interesting features come from these inventors and developers, not from the market. A competent group does not wait for users or prospects to propose features, but comes up with its own suggestions all the time.

This is usually the source of the most innovative ideas. Major breakthroughs do not arise from collecting customer wishes but from imagining a new product that starts from a new basis and proposing it to the market without waiting for the market to request it.

2. Suggestions from the field

Customers’ and prospects’ wishes do have a crucial role, especially for improvements to an existing product. A good marketing department will serve as the relay between the field’s wishes and the development team. Many such suggestions are of the “Check that box!” kind: customers and particularly prospects look at the competition and want to make sure that your product does everything that the others do. These suggestions push towards me-too features; they are necessary to keep up with the times, but must be balanced with suggestions from the other two sources, since if they were the only inspiration they would lead to a product that has the same functionality as everyone else’s, only delivered a few months later, not the best recipe for success.

3. Key customers

Every company has its key customers, those who give you so much business that you have to listen to them very carefully. If it’s Boeing calling, you pay more attention than to an unknown individual who has just acquired a copy. I suspect that many of the supposedly strange features, of products the ones that trigger “why would anyone ever need this?” reactions, simply come from a large customer who, at some point in the product’s history, asked for a really, truly, absolutely indispensable facility. And who are we — this includes Microsoft and Adobe and just about everyone else — to say that it is not required or not important?

It is easy to complain about software bloat, and examples of needlessly complex system abound. But your bloat may be my lifeline, and what I dismiss as superfluous may for you be essential. To paraphrase a comment by Ichbiah, the designer of Ada, small systems solve small problems. Outside of academic prototypes it is inevitable that  a successful software system will grow in complexity if it is to address the variety of users’ needs and circumstances. What matters is not size but consistency: maintaining a well-defined architecture that can sustain that growth without imperiling the system’s fundamental solidity and elegance.

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Computer scientist gallery, updated

After several months of inaction I have updated my “Gallery of Computer Scientists” [1]. It benefits from many recent meetings where the density per square meter of Turing award winners and other brilliant computer scientists was hard to beat, most notably the two extraordinary Turing centenary celebrations  — the ACM event in San Francisco, and Andrei Voronkov’s Manchester conference — and our own LASER summer school of last September which brought together the Gotha of programming language designers. And I still have not included everyone.

I do not know of any photographic collection anywhere that compares to this archive in either quantity or quality of the scientists pictured. My only regret is that I did not start earlier (I missed several giants of the field, to soon departed, such as Dijkstra, Dahl and Nygaard, even though I had many occasions to photograph them). The truth is that I had got impatient with photography and started again only when digital cameras became widely available.

The quality of the pictures themselves varies. It is definitely higher in recent ones: I may have become a better photographer, but it does not hurt that I have more sophisticated cameras than the rudimentary point-and-shoot I was using at the beginning. I should also improve the layout of the page, although I hope you will appreciate the ability to move the cursor around to get large pictures without having to click and go to different pages.

I started this collection because it occurred to me that for a number of reasons I am, more than almost anyone I know, in the position of meeting outstanding people from many different sub-communities of software engineering and the rest of computer science: from program verification, semantics, languages, algorithms to architecture, management, empirical software engineering and many others. I realized that it would be unconscionable not to take advantage of these opportunities and do for computer scientists what Paul Halmos did for mathematicians [2].

Some of the people pictured are more famous than others, but all do interesting work. There is no profound logic to the choice of subjects; it obviously depends on the chances I get, but also on the time I can spend afterwards to sort through the shots (this is not a full-time job). So if you know I took a picture of you and you do not see it on the page, do not take offense: it may be a matter of time, or I may need another opportunity and a better shot.

All the pictures are by me. They are of different styles; I try to capture a personality and a mood. Many shots show a computer scientist in flagrante delicto: doing computer science, as when giving a talk, or engaging in a design discussion around a laptop. Some were taken in more informal settings, such as a long winter walk in the woods. A few reveal some humorous or fancy aspect of the subject’s personality. None has any context or explanation; I will not tell you, for example, why Tony Hoare had, on that day, two hats and two umbrellas. I think it is more fun to let you imagine.

Pictures are only pictures and what matters is the work that all these great people do. Still, I hope you will enjoy seeing what they look like.

References

[1] Bertrand Meyer’s Gallery of Computer Scientists, available here.
[2] Paul Halmos’s photo collection, see here.

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Memories of a dark time

 

A few years back my mother started writing her memoirs. She only completed a few chapters, hand-written, and I offered to type them up. There was not enough material to approach a publisher (my fault, for not pushing her to write more); the text has remained unpublished. I am making it available now: see here.

It is in French; if there is enough interest I will translate it. (Although the text is not very long, it is well written so the translation should be done carefully.) For reference I have included below the entry about my mother in one of many books about the period.

Here as a taste of the text is a translation of a short extract from chapter 5 (Grenoble, 1942, where her mission in the resistance network was to find safe havens for Jewish children):

 Along with hosting familes there were religious boarding schools, and I should pay homage to a young Mother Superior, whose name I unfortunately forgot, who accepted some of our little girls cordially and without any afterthoughts. From schools for boys, however, how many rejections we had to suffer!

I also have to evoke that other Mother Superior, stern and dry, who after making me languish for several days while asking for the approval of her supervisors finally consented to see four or five little girls. I arrived with five of my charges, whom my neighbor had brought to me after their parents were arrested on that very morning. I can still see the high-ceilinged parlor, the crucifix on the wall, the freshly waxed and shining floor, the carefully polished furniture and a tiny figure with curly brown hair, all trembling: the eldest girl, who at the point of entering stepped back and burst into tears.  “One does not enter crying the house of the Holy Virgin Mary”, pronounced the Mother Superior, who had me take my little flock back to Grenoble, without further concerning herself with its fate.

And this note from the final chapter about the days of the Liberation of France, when under a false name she was working as a nurse for the Red Cross in the Limoges area:

This time it was the collaborationists’ turn to flee. I almost became a victim in a tragicomic incident when once, doing my daily rounds, I had to show my papers to a young FFI [members of the internal resistance army], aged maybe eighteen, who claimed the papers were fakes. Indeed they were: I still had not been able to re-establish my true identity. I tried to explain that as a Jew I had had to live under a borrowed name. He answered that by now all the “collabos” claimed to be Jewish to escape the wrath of the people…

 To understand the note that follows it is necessary to know a bit about the history of the period: the Drancy camp, OSE (see the Wikipedia entry), the Garel network. For the 100-th anniversary of OSE a documentary film was produced, featuring my mother among the interviewees; see a short reference to the movie here.

Biographical entry

From: Organisation juive de combat — Résistance / Sauvetage (Jewish Combat Organization: Resistance and Rescue), France 1940-1945, under the direction of Jean Brauman, Georges Loinger and Frida Wattenberg, Éditions Autrement, Paris, 2002.
Comments in brackets […] are by me (BM).

Name: Meyer née Kahn, Madeleine
Born 22 May 1914 in Paris
Resistance networks: Garel
Resistance period: from 1941 to the Liberation: Rivesaltes (Pyrénées-Orientales), Font-Romeu (Pyrénées-Orientales), Masgelier (Creuse), Lyons, Grenoble, Limoges
Supervisors
: Andrée Salomon, Georges Garel

In July of 1942, Madeleine Kahn was sent by Andrée Salomon and Georges Garel to work at Rivesaltes [a horrendous “transit camp”, see here] as a social worker. She worked there for several weeks and helped improve the life of people interned there; she managed to extricate from the camp a number of children that she took to Perpignan and moved to several hosting places such as Font-Romeu and Le Masgelier. In Le Masgelier [a center that hosted Jewish children], she was assigned the mission of convoying to Marseilles, for emigration to the United States, Jewish children who were of foreign origin and hence in a particularly dangerous situation. [These were children from Jewish families that had fled Germany and Austria after Hitler’s accession to power and were particular sought by the Nazis.] The local authorities had put them up in the castle of Montgrand, already used as a hosting camp for old Austrian refugees. The Germans’ arrival  into the Southern half of France [until 1942 they were only occupying the Northern half of the country] abruptly stopped the departures for the US, and the authorities changed the children’s status to prisoners, held in appalling conditions. Madeleine Kahn remained alone with the children. All escape attempts failed. They were only freed after a long time, and sent back in some cases to their families and in others to Le Masgelier.

In November of 1942, Georges Garel and Andrée Salomon put Madeleine Kahn in charge of organizing the reception and hiding of children in the Isère area [the region around Grenoble], which by then was still part of the Italian-occupied zone. [Italian occupation was generally felt much lighter than the German one, in particular regarding persecution of Jews.] The mission was to find hosting families or religious institutions, catholic or protestant, and in advance of such placement to prepare the children to their new [false] identities and help separate them from their parents [when still alive and not deported]. It was also necessary to obtain the support of some authorities, such as Mme Merceron-Vicat from the child support administration and Sister Joséphine of Our Lady of Sion. After a while Madeleine was joined by Dr. Selinger and Herta Hauben, both of whom were eventually deported. Later on she collaborated with Fanny Loinger [another key name in the Jewish resistance], who for safety reasons took over in Isère and particularly in the Drôme.

After the departure of the Italians [and their replacement by the Germans], the situation became extremely dangerous and she had constantly to move the children around.

Warned that she was being tracked, Madeleine Kahn hurried to reclaim two babies that had been left in the La Tronche nursery. The director refused to give her Corinne, aged one, as earlier on three Germans had come for her, wanting to take her to Drancy [the collection point in France for the train convoys en route for Auschwitz], where her parents were being held. Upon seeing the child’s age, the Germans had left, announcing they would come back with a nurse. Instantly, Madeleine summons her friends in various [resistance] organizations and the process sets into motion: produce a fake requisition order in German with a fake seal stenciled from a war prisoner’s package; hire a taxi; make up a nurse’s uniform for Renée Schutz, German-born in Berlin as Ruth Schütz. Equipped with the requisition order, the false German nurse arrives at the nursery while Madeleine acts as a sentry to stop the Germans if needed. Corinne, the baby, is saved. [I became friends with her in the seventies.]

The duped Germans were enraged. From an employee of the nursery they obtained Madeleine’s address, but she had left. The landlady gave them the address of Simone, Madeleine’s sister. [Simone was not a member of the network but knew all about it.] Interrogated under torture, she gave nothing away. All attempts to free her failed. She was deported to Auschwitz from where [adopting along the way an 8-year-old whose parents had already been deported, who clung to her, causing her to be treated like mothers with children, i.e. gassed immediately] she never returned.

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Technology plus

As the name indicates, this blog is particularly devoted to technology, and even more particularly to software technology. My technical persona is not, however, completely cut off from my personal persona and I increasingly include non-software topics.

Whether there is any readership equally interested in learning about using domain theory for specification and finding out what is the most beautiful monument of Europe remains to be seen, but from now on this will be my “technology+” blog.

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