Keith van Rijsbergen interviewed by Alan Macfarlane 15th July 2009

0:09:07 Born near Rotterdam in Holland in 1943; my memory kicks in at the end of the War; I remember my family parading in the street celebrating, although whether it was a memory given to me by my mother or I actually remembered, I have no idea; my father had quite a bad war; he was an engineer and he was on the run from the Germans; they wanted him to build things to do with their defences, and he refused; he was finally caught and sent to a prisoner-of-war camp on the Polish-East German border; some years ago when the wall came down I went and visited the place but the camp was gone; our life after the war was quite complicated as my father travelled a lot as an engineer and took the family with him; we left Holland for the first time about 1949 and we went to Indonesia; between 1945 and 1949 he had done some major construction work on the harbours in Rotterdam which I have records of; my brother, sister, and I, with our mother followed my father to Indonesia three months after, and settled in Jakarta; father doing work on the harbour; we lived right in the centre of Jakarta very close to a famous river called the Kali, and our neighbour was Sukarno; he lived in a huge house and we lived in something like a hotel; I went to school there; about ten years ago I met a fellow computer scientist, a Dutch man, and found that we had been in the same primary school in Jakarta; my father stayed in Indonesia for about three or four years; during that time we moved around and spent time in Surabaya, also in Java, some time in Borneo, and also Sumatra; in all these places I went to school and learnt to speak Indonesian as did my brother and sister; we conversed in the language but some years after we had left, completely forgot the language; the memory of that time is still strong because it was like an adventure; I was completely free to roam around in and out of the jungle, so a very happy memory; I have never been back although I have wanted to

6:33:03 My father was a quiet type; occasionally he would lose his temper and hit us, but not in a severe way; most people would say I was not very close to him but he looms because it was his activities that determined where we went and what we did; my mother was an extremely nervous person; she almost had a nervous breakdown having to follow my father to Indonesia; this was displayed in huge arguments with her children; as the youngest I was more of an observer but she certainly upset the others; however, the relationship between my mother and myself was actually quite close; she was always at home, my father worked twelve hours a day, so she was quite influential in many ways; she always gave us, particularly me, a lot of freedom to do what we wanted, providing we told her what we were doing and when we would be back; none of the family actually finished school or were academically inclined; my mother only went to primary school, father only had three years of high school and my brother and sister similarly; I was the only one who was academically inclined and my parents did not understand this and tried to encourage me just to get a job

9:47:09 I start to remember things about school from the age of about fourteen-fifteen, prior to that I have virtually no memory of school, certainly not Indonesia; I can recall going to school and leaving it, and doing things out of school, but have no memory of anything in it; realized I was quite good at mathematics when I was going to high school but there were no signs of this before; after Indonesia we went back to Holland; this was a recurring pattern; the next contract was in Western Australia and we lived on the outskirts of Perth; I went to a normal primary school and have a bit more memory of this as it was there that I learned to speak English; when I first arrived at the school the teacher told another boy to take me outside and teach me the alphabet; that is the only thing that I remember about learning English, the rest was by a sort of osmosis; my parents attitude was that wherever we were, the children should go to the local school, whatever the language, and just get on with it; I don't remember anything traumatic about not being able to speak English; at that school they discovered that I was quite good at maths and science; after about a year and a half they pushed me on and I was put into first year high school a year before I should have been; however it didn't help much as we soon after left to go back to Holland; I have some minor memories of living in Perth, a little of school, but more of biking to the beach and spending time swimming; in winter I would spend time walking in the bush with a friend; a lot of my time was spent outside; I did read a lot but it didn't interfere with my outdoor life; the school was Hilton Park Primary School and I remember a teacher by the name of Simpson; many years later I bumped into him in Fremantle although he didn't remember me; I think I remember him for his kindness and not for being a good teacher; at that stage I don't have much of a memory of teachers being good or bad; I remember them being more or less violent as they still caned people, but he was rather a kind person; while we were in Western Australia the Queen visited, probably in 1953, and came to the school, and I remember that as a big occasion, but the strongest memory I have is of swimming

16:00:00 Our walks in the bush were not systematic; we were not collecting things but pretending to be Cowboys and Indians; the bush was on the edge of where we lived so I only had to cross the road to it; it was not particularly dangerous and we went barefoot; we then left Australia and again went back to Holland; from a school point of view this was quite a critical moment; I think we may have lived with my grandmother for a while; because I had just gone to the high school in Fremantle I was then put into a high school in Dordrecht; it was called the MULO which is a school which teaches children useful things so they can go into commerce; at that school they discovered that I was quite bright academically; it was recommended to my parents that I be sent to the HBS which is like a Gymnasium and streams children for university; that is where my interest in science and mathematics took off; I had to get some extra coaching in mathematics to catch up; I realized that I was rather good at physics as well; we went back to live in the place where I was born; that was where I grew to love going to the cinema, read a lot but mostly light stuff, and continued swimming

19:56:01 Started to wear glasses in Australia just before going to high school; I remember feeling quite shy at having to wear them but don't remember it persisting; I was not a keen games player, but my favourite sport was swimming; always felt other games were constraining; I was not a great team player; I was quite rebellious; in Holland I was actually suspended from school for a few days but can't remember why; I probably was slightly resentful of authority, not being allowed to do the things that I wanted to do, and this led me into trouble; in Australia I used to go around pinching fruit from orchards; back in Holland in what I thought was a reasonable education system, I was also taught French and German; the Dutch system in those days was very extensive; I think I had about seventeen subjects, and they were done to quite a reasonable standard; one of my memories of that period is that I went to the World Exhibition in Brussels, in about 1957; just before that the Sputnik had been put into space and the Russians had a display model at the exhibition; there were also displays of, what were then, modern technologies; I remember seeing the first colour television set in the American pavilion; we had family in Brussels and used to visit them quite regularly; my father came from a very large family and some of his brothers lived in Belgium; my mother came from quite a small family and her father was a market gardener; she had a brother and sister; she did not keep up much contact with her family; I still have contact with my father's family, but not in Holland

25:47:19 The next stage in my father's career was to go to what was then called South West Africa, Namibia; this was the last three years of high school; we lived in a town called Walvis Bay on the coast; the school was in Swakopmund about forty miles away; I travelled there every day by bus; although the school was Afrikaans and English a lot of the kids were German, so I learned to speak German simply by osmosis; I read a lot in German and Swakopmund had a very good bookshop; one of the books that influenced me in the direction of science was Fred Hoyle's book 'The Frontiers of Astronomy' which I read in German; that was when I started to look a books that had serious scientific content; I read Rutherford on the atom and Eddington's 'Nature of the Physical World'; I was also reading literature including Dostoyevsky; I saw myself as part of the beatnik generation though probably all it meant was wearing a floppy sweater; it was the time that academic-type reading became more important; I continued to swim despite a cold current which comes up from the Antarctic along the west coast of Namibia which makes the water very cold; there is a pier in Swakopmund that goes out into the sea and I used to swim around it every day; again, a lot of my memories are of things I did outside school; in my holidays I worked on a fishing boat; in the summer the boat would function as a trawler and I worked as a deckhand, sorting fish; in winter it was converted to catch pilchards by net, and that was a night activity; another thing I remember well was going up-country, hunting with a friend whose parents had a farm; I spent quite a lot of time walking round the desert near where we lived; in terms of friends, in Namibia at Swakopmund I made a very good friend whom I remained in contact with for quite a few years afterwards; the friends I made before that I did not keep in contact with for long; as a family we also went on vacation in South Africa; we had a Land Rover so would drive down to Cape Town and Durban, so we saw quite a lot of the country; towards the end of our stay in Namibia I was in a major train crash; I was on the way to visit my brother in Durban and there was a head-on collision with another train; I was in the front coach; the engine went straight through the coach and smashed its way through until it got to my compartment; all those in front were killed; I crawled out of the wreckage virtually unharmed; I had the presence of mind to take photographs and then walked off to the nearest road, hitched a ride and continued my journey

34:41:24 On religious background, my parents inherited their parents' religion which was fairly protestant Calvinist; there was a moment when I was six or seven that they said that I didn't have to say grace before a meal if I didn't want to; I think that they had lost their religion; I think I decided I was not religious about the age of fourteen; I had no desire to go to church and didn't personally think that I believed in God; Martin Rees once said that he was a non-believing Christian and I think that that is quite close to what I am; I understand and accept the culture that we have has come out of Christianity, but that doesn't mean to say that I also have to believe in God; when I was a teenager in Namibia I read a lot of Spinoza and that must have had an impact on me as well; there were things I read that made me become more sceptical about religion; my wife is the daughter of an Anglican Vicar and that made me take an intellectual interest in theology; I am not like Richard Dawkins, I don't feel antagonistic towards religion; if people want to believe that is fine; I actually enjoy having proper theological arguments; the other thing that happened in Namibia was that I stayed on for my last year of school, on my own; my parents went back to Holland but they arranged for me to be accommodated in a maternity home which had rooms that were rented out; when I had first arrived in Namibia my parents had enquired about an appropriate school for me; the headmaster determined that as I did not speak Afrikaans I would have to learn it; they decided that I should go into a hostel at the school; unfortunately I was not very popular because I had made a lot of English/German friends and there was antagonism between them and the Afrikaners; every few days I would have a fight on my hands having to defend myself; eventually I got fed up; I rang my mother and told her I was coming home; they must have realized that it was serious; the school decided I could stay although I had not really learned enough Afrikaans; at the end of my time at that school you had to take not only your leaving certificate but also a certificate in English and Afrikaans; I decided that the mathematics at school was poor and I explained this to my parents; they suggested that I signed up for a Dutch correspondence course, which I did, and this brought my mathematics up to a standard that went beyond what was offered by the school; I think that from going to school there I got my love of languages and literature; languages, especially English literature, was taught to quite a high standard and we were expected to read quite a lot; the English literature teacher was one of the people that I remember very well, and I liked; he was a rather unusual person who would invite me to his house and I would play chess with him; I think he must have realized that I was academically inclined because he always encouraged me

43:48:10 I had enrolled to go to university in Natal to study mathematics and had got a scholarship to do that; my parents then wrote to me to say that they were going back to Australia and were coming to collect me on their way; we met in Durban where my brother was; my sister had already gone back to Australia; with them and my brother we went by a cargo vessel to Australia; I was again moved to another education system and it was not as straightforward as they had said it would be; it turned out that the University of Western Australia didn't recognise my qualifications; they agreed to let me start provisionally while trying to get my qualifications accredited; about two-thirds of the way through my first year they agreed finally that I could stay; I wanted to do physics and philosophy as well as mathematics; the University would not allow philosophy so I started to do physics, chemistry, pure mathematics and applied mathematics; I felt this a bit of a compromise as I wanted more than just pure science; I had quite a lot of catching up to do in some aspects; no sooner had I started my course than my parents left and went to the east coast of Australia; once again I was left on my own; I learned that I left South Africa at the same time as David King, in 1962; he left for political reasons and I realize that in my three months in Durban I was becoming politically aware; up to that point although I was aware of Apartheid and that it was questionable, it was not a big issue; when I was in Durban I got to meet some of the students and they were fairly political; I went to some of Athol Fugard's plays, one I remember clearly was 'Blood Knot' which was closed down almost as soon as I had seen it; I started to get concerned so maybe it was quite a good thing that I was leaving South Africa; talking to David, although he was more advanced in his thinking at that time, we were struggling with the same thing

49:14:24 My mother at that stage had calmed down; one of the things that had happened in Indonesia which was perhaps one of the reasons she was extremely nervous, was that my father was nearly murdered twice; he was in charge of people on the engineering site and for some reason they decided to run him over with a truck and left him for dead; he recovered, but no sooner was he out of hospital than they tried to kill him again, with knives; at that time there was a lot of tension between the Dutch and Indonesians because the latter was becoming independent and the Dutch were the old colonial masters; my mother just didn't believe that my father was going to die so she stayed with him in hospital and he recovered; when we were back in South Africa and took the boat to Australia I remember her as being quite calm and at ease with herself; when studying I met my wife, Juliet; we met in the mathematics lecture theatre and because we were both short-sighted we had to sit in the front; we went through our first degree together and married in 1965 at about the time we graduated; I did not like the formal education that I was getting, and resented the canned, limited and boring way in which they presented stuff to us; I thus spent a lot of my time getting books out of the library and reading around subjects; I would take notes in lectures but would burn them at the end of the year as quite useless; I seemed to have an approach to science that I had to get the story in my head that at other times I could think about the stuff; it was not enough to just have the proof; in mathematics they would, for example, give a lecture on the Hahn-Banach theorem, then meticulously go through the proof on the blackboard; this did not work for my and I found it totally uninteresting; I had to go away and read about the Hahn-Banach theorem, and how it fitted into other bits of mathematics; maybe even read about the people involved, so for me always my interest in science was added to by knowing about the people who were doing it; before I came to university I had already read and understood the special theory of relativity, but at the same time I had found out a lot about Einstein; I wanted to do theoretical physics because of this; the physics department in Western Australia had a strong experimental component and I found it boring; you had to stand doing experiments in the afternoon, and they would take three hours; at that stage suffered very badly from migraines, particularly when standing for long periods; this wiped out the rest of the day; I told the Professor of Physics and asked if I could do just theoretical physics; he said I couldn't do just theoretical physics so suggested I focussed on applied mathematics; that is what I did; it was a strange period because I think the University worked their students very hard but I felt they did not instil any excitement about the subject during the lectures, and did not motivate us well; the dropout rate in mathematics was very high so although I started with a large cohort, by the time I got to the end very few were left; I thought I was not going to make it because when I was tested by a psychologist in my first year he said that I was totally unsuited for university work; I think it may have had something to do with my command of English at that point as I had been speaking German or Afrikaans; the thing that I remember most about university is finding these wonderful things to read in the library; that is how I learned a lot of stuff I had to learn, lectures just didn't work for me; my wife seems to think I did the right thing as she just concentrated on the lecture notes and now retains nothing of that stuff, whereas I have retained the story

Second Part

0:07:09 I did not have a scholarship so I had to pay my own way; I worked as a crayfisherman, a weighbridge officer, an assistant electrician, in an auction room, as a quantity surveyor, so had a string of experiences in different types of jobs; by this means I paid most of my way through university; at the same time my relationship with my wife went from strength to strength and we are still here; after graduating we decided that we wanted to leave Western Australia and go back to Europe; before doing so, with a degree in mathematics, felt I needed a meal ticket; I therefore enrolled for a year in a diploma course on numerical analysis and automatic computing; thus I retrained as a computing person; surprisingly I discovered that I liked it; my wife, also with a degree in mathematics, took a diploma of education; we got on a boat with a number of other graduates and came to England; before setting off I wrote to a number of places in England with computing centres asking for a job; I did not come here with the intention to do a PhD; a letter was sent to the Computing Service in Cambridge; Eric Mutch was the head of the service but he had no job to offer but he contacted Nick Jardine; they thought they might be able to offer me a job as a programmer; I arrived in 1969 and was interviewed by Nick Jardine in King's; he said he could give me part-time employment but that the Computer Lab could also offer some work; Nick had a project with Robin Sibson, who was also in King's at that time; they had just finished their PhDs on automatic classification in the biological sciences; Eric Mutch died soon after I arrived, but I continued in the lab working on a sub-routine library in numerical analysis which ran for many years on TITAN; after working for about nine months I told Nick that I was getting very bored; he suggested I do a PhD; the idea I had for it grew out of the work I was doing for Nick and Robin in the King's College Research Centre, which was to try and use automatic classification techniques in information retrieval; I had an interest in information retrieval even before I left Australia so had already read about it when I arrived in Cambridge; I put these things together and this was how I got to know Karen Spärck Jones; King's College was going to have me as a research student and subsidise my fees; I remember assuming that I could do a PhD in information retrieval providing I was not supervised by Karen Spärck Jones; Ken Moody who at that stage had an interest in databases took me on; I think that was a stroke of genius because I collaborated with Karen all along but it was not a student-supervisor arrangement; she was generous in giving me access to the test data she had but was not my supervisor; I also got a lot of help from Roger Needham

9:06:08 The history of information retrieval in Cambridge is quite interesting; Roger Needham, a famous computer scientist in a totally different area, did his PhD in information retrieval; I suspect that it was the first PhD ever done on that subject; he was supervised by David Wheeler who is one of the pioneers, and worked with Maurice Wilkes; there was a progression David to Roger who, to a certain extent, helped me; Nick and Robin had conversations with Roger with their work in automatic classification because he and Karen worked together in the Cambridge Language Research Unit on the theory of clumps; I think that Karen got her initial ideas about information retrieval probably from Roger; Karen came in as a linguist where she had done her PhD work, which apparently, even now, is still read and considered to be very good; it was on synonyms; her thesis was republished recently under pressure from Yorick Wilks; he was also a member of the Cambridge Language Research Unit, which also had Fred Parker-Rhodes, who may also have done some work on information retrieval, and also Margaret Masterman; the group that I knew worked on language and linguistics and shaded into stuff on information retrieval; when I was starting to work for Nick and Robin there was this huge intellectual disagreement between them and the Needhams because the clumping process was considered to be very unprincipled, whereas the approach adopted by Jardine and Sibson, later Jardine & Sibson 'Mathematical Taxonomy', was considered very principled and mathematically well defined; as it turned out the algorithms or methods of automatic classification that came out of their work was relatively efficient, whereas clumping was horribly inefficient; what happened in the end was that the Jardine-Sibson work that turned into my work too, survived, whereas the clumping didn't; I was caught between these two groups but I had my office in the Research Centre where at the same time Denis Mollison, a probabilist, was also working; his application was pandemics so had mathematical models for the current flu pandemic; he became Professor of Statistics at Heriot-Watt and was on the fringes of our project; the other person who was quite involved with the project was Ken Moody; I don't know whether he was officially written into the project proposal but he was certainly acting as a consultant; he designed the original algorithm for a sequence of cluster methods called BK, the core of which was based on his work; as a supervisor he took an interest in what I was doing when it really mattered; I was an appalling writer to begin with, it was so condensed that if I was to write the same stuff now, one paragraph would take several pages; Ken got me to think about how to write; I went on to do my PhD thesis on automatic classification techniques; I tested them to show that if used in the way that I did, at least on the data that I had, it showed that you could get major performance increase; on the way I also invented an evaluation measure which is used to this day, in fact is used very widely in speech recognition, so was adopted by another field as a measure of retrieval performance; it was some of the theoretical work that I really enjoyed doing; I went back to some theory called the theory of measurement that suggests that if you want to measure something where the objects are in a qualitative relationship, what you have to do is to define a mapping of these to a numerical representation where properties of the qualitative structure are preserved; I took that approach to measuring performance in information retrieval; I wrote down the intuitive conditions or relationships that were important in IR and the ones that you wanted to measure, and then defined this mapping; I came up with this new way of measuring things and it has persisted; it is still used in information retrieval and also in speech processing; so automatic classification, the method and the algorithms for IR and this evaluation technique were really the guts of my thesis; Karen, who really was not mathematical on the whole, helped me with the linguistic stuff; she was the one who explained to me about stemming and stop words, and the way it was driven by some background in linguistics; she had also built up some test collections and she allowed me to use them; our interactions were mostly around the experimental side of information retrieval

19:02:06 While I was doing my PhD, my wife taught at a number of schools, especially Impington Village College, and after a difficult first six months in Cambridge we ended up being happy here; Maurice Wilkes only entered my life towards the end of my PhD; he really didn't see the point of information retrieval; I thought that information retrieval should be a subject in the computer science curriculum and he never really allowed that; I think Karen half agreed but was ambiguous about whether she wanted it as part of a computer science degree; she had quite an interesting attitude to IR; she saw it very much as a post graduate activity but then she took very few PhD students; she had one, David Jackson, who preceded me, and after that there was a huge gap; what she did do was to supervise students in natural language processing; she did supervise Martin Porter but in macro processors; there was a language called Snowbol, and he designed and invented a comparable language; he was a superb software engineer; Martin came into our lives when I came back again from Australia; after I took my PhD I was head-hunted by the Professor of Computer Science at Monash University in Melbourne; his name was Chris Wallace and he worked on automatic classification; he was a good, able, academic, but it was different from the automatic classification work that people did here; we went out to Monash and there our daughter, Nicola, was born five months after we arrived; however, as a lecturer in computer science I got very bored; I had nobody to talk to really about information retrieval; I had the idea of talking to myself and wrote a book about it; the book did well and is still used to this day; half-way through my contractual period I returned to Cambridge to try and figure out if there was a way that I could come back; Karen suggested I apply for a Royal Society Research Fellowship which I did; I got it, so after two and a half years in Monash, I came back to Cambridge and bought a house

24:56:16 Academically there was a development going on in information retrieval which turned out to be extremely significant, in fact theoretically probably one of the most important in the subject; there are various models for information retrieval; the standard one, probably the oldest, what we call a vector space model, researched by  Gerard Salton at Cornell; the sense was that there was enough uncertainty in information retrieval processes that we had to use probabilistic approaches; the first major development in that area was a thesis written by an academic, Bill Miller, at Newcastle University; he invented a new model - probabilistic retrieval as it is now called; the trouble was that it was only half a model; Karen working with Stephen Robertson but he was in danger of not having a job; we worked out a way of employing him as a research assistant; on that project we also employed Martin Porter as another research assistant; he was working on probabilistic models for our project so the suffix stripping algorithm, called the Porter Algorithm, was invented on the project; I gave him the task of building one and he did a fantastic job; he went and read all the literature on such algorithms on the linguistic side and computing side, then he put it all together and produced this algorithm; it is still used; any information retrieval experiment that is done, even with commercial systems, they tend to use the Porter Algorithm; Martin was not really a researcher, more of a developer, writing the software and building a system; he and Karen did not get on so one of the problems we had on the project was that every so often we would need something from Karen and then she would give him a hard time; he was not good at coping with that; Karen was very forthright and Martin didn't like to be hassled, so got very upset; Stephen, who was going to be on the project, at the last moment got a job so he became the co-investigator with me, so we employed Martin; I think he is a brilliant software engineer, one of the best I know in terms of getting things done; I was on the fringes of Muscat; he took an earlier system that he had written for the Museum Documentation people and extended it, as I saw it, with some information retrieval functionality; some of that he probably got from working with myself earlier on

31:24:10 My relationship with Maurice Wilkes got better when I became interested in Alan Turing; Maurice is very aware of his position in the history of computer science, and rightly so; he is one of the founders and pioneers, and certainly you can make the argument that, with David Wheeler etc., he built the first real computer, the EDSAC; Alan Turing, especially at the moment, but certainly towards the end of the 1970s, became more well known for his work; at that time the Scientific Archives in Oxford rang King's and said they had papers by a man called Turing who seemed to be originally from King's; they asked if King's could send someone to say whether they were worth preserving; the Librarian, Peter Crofts, asked me to go and look at them; like everybody else I had heard of a Turing Machine but I knew little more than that about him; I saw the papers and suggested they were brought to King's; progressively King's got more and more serious about them and I later got some money to help with them; at that time most people would not have heard of him but I talked to Maurice Wilkes at some time and he clearly felt that Turing was being given too much prominence in the history of things; you can see that from his point of view, Alan Turing was a theoretician and wrote this incredibly smart paper in the 1930s on the Entscheidungsproblem; he spent the War at Bletchley Park involved in the design of computers - (not the Colossus, that had nothing to do with him) ; after the war, when working at the NPL, he wrote the ACE Report, a blueprint for designing a computer which was in contrast to a similar report written by John von Neumann which was the EDVAC Report; the EDVAC was the first complete design for a computer and Turing's came a little later; Wilkes, on the other hand, started to think about building EDSAC and got his information from the same sources as von Neumann and Turing; Eckert and Mauchly  who gave courses in the Moore School of Electrical Engineering, University of Pennsylvania, were the source of new ideas about a modern computer; Wilkes's attitude was that he was just going to build it, and as an engineer that is what he did; he tried to collaborate with Turing but they didn't like each other; the EDSAC was built and was a success; the ACE machine was only built very much later in the 1950s, so its impact on the design of the next generation of machines was not very significant; however, I think that Maurice sees Turing as unjustifiably getting more support than he ought to because his work was theoretical and as far as building the computer, his engineering skills were not great; nowadays everybody has heard of Turing because of the books and films which Wilkes would feel overstates what he actually accomplished; I am a great admirer of Turing but more for his theoretical work; I think his thoughts on the Turing Machine were an incredible breakthrough but his contribution to the actual building of computers is nowhere near as significant as Maurice's are; Winston Churchill said that we were saved from a German invasion by him but in a letter to him, I think Churchill said that it had shortened the War by about a year; Turing started work on encrypting using his theoretical knowledge, so the bombe, the mechanical devise to do the decoding was based on the theoretical ideas Turing had at Bletchley Park; after that early period he was not working on that any more; he got moved onto speech encryption; the work that led to the Colossus was independent, and Turing was only on the edge of that; his story was very sad; he moved to Manchester and worked in the computer laboratory there; he was forced to undergo drug treatment because of his homosexuality; the book his mother wrote about him is a delight to read; I have interviewed Maurice about Turing as I wanted to know whether he had read the ACE Report about the design of a modern computer; Maurice claims he did not read it and worked independently of Turing

42:45:17 I was at Monash at the time that Stephen and Karen were working on probability; I also made the shift in my mind and had a student build a probabilistic search engine as a student project; my approach to it was slightly different; I took a decision theoretic approach so developed some sort of decision theory, so when Karen and Stephen produced their draft paper and sent it to me, I reworked it in decision theoretic terms which is I still think a good way to do it; there was a kind of debate going on between the three of us about how to formulate it; some people would say that the probabilistic model (which I wrote about in the second edition of my book) was actually developed by the three of us; however, if I am honest I certainly think that I probably had the same ideas to the same extent; the paper that was published by Karen and Stephen is the first publication of that work although it has a subset in it which is on the decision theoretic approach; in the other way that I was in the thick of it was that I started building, together with Martin, implementations of it; for example, the relevance feedback comes out of that model; I was much more interested to get it working at that stage than to define the theory; like a lot of these things, it is very difficult to pinpoint where the breakthroughs were made; there was this earlier thesis by the Bill Miller from Newcastle, who actually ended up in Glasgow University, who had a pretty good formal development of it, but he didn't seriously take into account the non-occurrence of things, thus it was half a model; it was completed in the paper by Karen and Stephen; I should have had my name on that, but I didn't

47:21:15 I don't have great thoughts sitting at a computer terminal; to this day I still hand-write important stuff first and not at home; I am one of these people who actually works in cafes; most of my papers were drafted by hand in a notebook in a cafe somewhere; I worked for a long time in the old 'Copper Kettle', and I wasn't the only person that did; Green, who contributed much to string theory, was working in another corner, though at that time I had no idea who he was; I used to get ideas in the bath and when cycling; it would be unusual for me to sort something out sitting at my desk staring at a blank piece of paper or a screen; I can't sit still for very long either; if I work for an hour and a half I then have to go for a walk anyway, I am a restless researcher

50:35:03 I enjoy music, particularly singing and jazz; my background meant that none of my siblings or parents played any musical instrument; until the age of sixteen there was not a record player in the house; my mother and father were pretty much a-musical; my brother liked to play the mouth organ but was exposed in the same way to not having any music in the house; I only discovered music gradually, I absolutely adore opera and am a great fan of jazz, especially blues; I use music as a way of relaxing; I used to take a bath to do that; now if I come home shattered, I put on a piece of music - recently Handel's 'Julius Caesar’ - and I just listen to the whole opera; my wife and I share the same taste in music so wherever we go we try to go to performances as I also enjoy the staging; I also read a huge amount of fiction both in English and in Dutch; again it is a way of escaping from the technical stuff that I do

55:09:17 I have supervised about thirty PhD students and about 60% of them are now full professors around the world; in my supervisions what I try to do is to engineer one thing; I want them to have the central idea themselves, they should come up with it if the possibly can, although I might stimulate it, but then I want them to end up owning it; then when I start to argue with them they show clear signs that it is their idea; once they have reached that point then they are well on the way; how do you do that? I say that they should follow their noses, and choose to do something they are interested in and want to do, not something that they were just told to do; it seems to work although I have had students where it has not, and generally they don't do as well in terms of a career afterwards; I believe in the academic way of life and have enjoyed it immensely; the thing that I have resented in the last ten to fifteen years is the extent to which the bureaucracy in universities have started to drive things; they create circumstances which academics have to respond to which are basically just stopping you from doing the intellectual work; it is not that I feel that academics should just do intellectual work, but the burden of doing the non-intellectual work, dealing with either national or local bureaucracy, has become rather over-excessive and I think very sad; my daughter is an academic, a post doc in neuroscience, and I can see that the pressure is there already on her to cope with bureaucratic excesses