Ontology pub quiz questions of ISAO 2016 and JOWO 2017

In 2016 when I was a PC chair of the International School for Applied Ontology (ISAO 2016), the idea of organising a contest for the participants turned into a pub quiz somehow. The lecturers provided one or more questions on the topics they’d be teaching and I added a few as well. This set of ISAO16 ontology pub quiz questions is now finally online. It comes with the warning that it is biased toward the topics covered at ISAO 2016, and it turned out that there were a few questions not well formulated and/or not everyone agreed with the answer.

Notwithstanding, it was deemed sufficiently ok as idea in that the general chair of the Joint Ontology Workshops (JOWO 2017) wanted one for JOWO 2017 as well. Several questions were thrown out of the ISAO16 set for various reasons and more general Ontology questions made their way in, as well as a few ‘fun’ and trivia ones in the hope to add some more entertainment to the ontology pub quiz. The JOWO17 pub quiz question set with answers is now also online to play with, which, in my opinion, is a nicer set than the ISAO16 one. Here are a few questions to give you a taste of it:

  • Where/when can a pointless theory be relevant?
  • What is the goal of guerrilla ontology?
  • No Italian pizza has fruit as topping. Which of the following is (an)/are Italian pizza(s)? Pizza Hawaii, Pizza margherita, Pizza bianca romana (‘white roman pizza’)
  • When was the earliest published occurrence of the word “ontology”?

It turned out that it still was not entirely free of debate. If you disagree with one of the answers now, then let me paraphrase Stefano Borgo, who co-ran the JOWO17 pub quiz at the Irish pub in Bolzano on 23 September: maybe there’s something there to write up and submit a paper to FOIS 2018 :-). Or you can write it in the blog post comments section below, so that those questions will/should not be recycled and I can add longer answers to the questions.


Book reviews for 2017

The third, and probably for a while last, post in a row that has not much, or even nothing, to do with my current job and research interest: the seventh installment of short book reviews and opinions on a selection of fiction and non-fiction books I read last year.


Dataclysm by Christian Rudder (2014). This is a highly entertaining book about some interesting aspects of Data Science. The author, one of the founders of the dating site OkCupid, takes his pile of OkCupid data and data from some other sources, and plays with it. What do those millions of up- and down-votes and match answers reveal? What’s the difference between what people say in surveys and how they behave online on the dating site? A lot, it appears. The book makes the anonymised aggregates fun and look harmless rather than Big Brother-like to haunt an individual. A bunch of people copy-and-paste messages, but it doesn’t seem to matter for replies and interaction. Looks matter, a lot, but weirdness, too. You’re a women over, say, 25 and the man says you’re gorgeous? Probably lying: they dig the looks of 20-year old women most, no matter how old they are. The portion of people identifying as gay correlates with societal and legal acceptance of same-sex relationships and marriages. And so on. One has to bear in mind that the conclusions drawn from the data should be seen in the light of self-selection (are the OkCupid members average in the sense of collectively being like the whole population?), that pattern-finding is different from hypothesis testing, and accidental data is different from collecting data in a controlled setting. That said, it’s still interesting to read about what the data says and it offers a peek into the kitchen of online dating sites.

What the dog saw by Malcom Gladwell (2009). It’s not nearly as good as the others. In a way, the narrative is the opposite of Dataclysm (as Rudder also discusses): Gladwell’s books are more about the peculiar particular and trying to generalise from that, whereas Rudder takes the aggregates over very large amounts of instances that is the general trend backed up by data rather than anecdotes (which isn’t the plural of data). Both books were very USA-centric, which became annoying in What the dog saw but not with Dataclysm.

Gastrophysics—the new science of eating by Charles Spence (2017). I’ve met people who can’t even believe there’s such thing as food science—an established applied science and engineering discipline—so perhaps the reader’s first response to the term ‘science of eating’ may be even less credulous. But sure enough, there’s truth to that. As the blurb about the book ended up longer than intended, it got its own blogpost: gastrophysics and follies. In short: the first part is very highly recommended reading.

I didn’t manage to finish Slavoj Zizek’s “Trouble in paradise—from the end of history to the end of capitalism”. There were fine parts in it, but there was too much rambling on too many pages, piling dialectical upon dialectical topped-off with upside-downs that the plot got lost and the logic missing. I searched online for book reviews of it, wondering if it was just me being too tired to concentrate, but turned out I’m not the only one. 17 contradictions and the end of capitalism by David Harvey was better (reviewed a few years ago).


Indaba, my children—African tribal history, legends, customs and religious beliefs by Credo Mutwa (1964). This book was recommended to me with the note that although the author made it all up, for there are no such stories among the amaZulu, it is great storytelling and a must-read nonetheless. It is indeed. The first part chronicles in a fantastic way the story of creation and the first humans as a poem that is best read aloud for the most dramatic effect of the unexpected turns of events. Parts two and three see successive interactions with intruders and societies rising and falling, the organisation of society, their laws, customs, rites, and quests for power, with a bit of interference and nudging here and there by the goddesses, immortals, and the tree of life. Part four consists of reflections, events, stories, and criticisms of the recent past. Woven into these stories are how the things came to be as they are, such as the creation of the moon, the naming of the marimba (a type of xylophone), how/from where the Swazi and amaXhosa originate, and so on. The tome of almost 700 pages takes a while to finish; yet at the same time, one feels that loss once having finished a great book.

The drowning by Camila Lackberg (2012, translated from Swedish). This is a ‘whodunnit’ crime novel with twists and turns and even if you think near the end of the book that you know who’s behind the threats and murders, you’ll still be surprised, and perhaps somehow a bit sad, too. That much for spoilers. The general storyline has the novel set in a village in Sweden where village life seems idyllic, but all sorts of things are not what they seem—the ‘marital bliss’ that’s not so blissful after all, and so on. Christian Thydell published his first novel and gets great reviews, but has been receiving anonymous threats, and soon a few other men in the village get them as well. Gradually, a few people die or are murdered. Erica Falck sets out to uncover the truth informally, while her detective husband tries to do so in the official police investigation. With the cross-fertilisation of information, eventually the mystery is resolved.

How to fall in love by Cecelia Ahern (2014). I recall the time when Ahern’s first novel came out in Ireland, where the first reactions that she’d published a book was a like “well, bleh, but she’s the daughter of…” [the then Taoiseach ‘prime minister’, Bertie Ahern], yet then reviews came in like “actually, it’s really sweet/nice/quite good/etc.” and it ended up as an international bestseller and a movie (P.S. I love you). So, when I was recently in Ireland, I decided to buy one of her books to see for myself, which turned out to be her latest novel How to fall in love. Sounds just as cheesy, true, but the nutshell version of the story is quite grim. The protagonist, Christine Rose, talks a stranger (Adam) out of his suicide attempt with a deal: that she can convince him in two weeks’ time that life is worth living; if she can’t, then he still can go off and kill himself. She had just walked out of a relationship; he had found his fiancé cheating with his best friend (among other reasons why he wanted to kill himself). Christine then comes up with a range of ‘mini-adventures’, mostly set in Dublin, trying to fix it yet having no real experience in suicide-prevention support. Some activities and meddling work out better than others. The storytelling is heart-warming, funny, and light-hearted, yet at time serious and depressing as well (suicide is quite a large problem in Ireland, and higher than the world average). Several unexpected turns in the story and development of the characters and their motivations keep it interesting. It is a fairly quick read for its easy writing style, yet also one of those books that one would like to read again for the first time.

Woman on the edge of time by Marge Piercy (1976). I bought the book because it said “The Classic Feminist Science Fiction Novel” on the front cover. Frankly, that’s rubbish. If Americans think that’s feminism and sci-fi, then no wonder gender parity hasn’t been achieved and science is facing tough times there. Anyway, the story. The protagonist had dreams of education and independence and is sane but was put in the insane box and she goes along with it, with some weakness and whining about oppression here and there. What exactly is feminist about that?! The supposedly sci-fi part is the protagonist doing some mental trips to a future of “sexual, racial, and environmental harmony”. She can do that because here mind is “receptive”. Seriously? Really, there’s no smell of ‘sci’ there, just a lot of ‘fi’. If there were a single classic in the genre of ‘futurist fiction for feminists’, I’d say it’s most definitely kinderen van moeder aarde children of mother earth’ by Thea Beckman that I read back in the mid ‘80s. I still can remember the storyline now, more than 30 years later, without having read it since. The setting is in Greenland that, after some terrible nuclear war that has moved continents, was pushed south into a moderate climate whereas Europe ended up at a latitude where it’s a scorching hot climate. Thule (Greenland) is governed by women—because it was the men who screwed up with their wars—and now a dirty steamboat with exploitative patriarchal Europeans is arriving. The book describes how that society functions where women run the show (e.g., there are no prisons). The protagonists are two teenagers—one son of a female member of the governing body, the other his girlfriend from the commoners—who think that it isn’t fair that only women from the ruling hierarchy rule. In the end, they manage to neutralise the invaders and a few men get some say in governance.

The Power by Naomi Alderman (2016). As the saying goes, don’t judge a book by its cover. But the book’s front cover looked really cool and the back cover story sounded like an interesting scenario, so I ended up impulse-buying it anyway. It turned out to be a page-turner. The main part of the novel describes the unfolding events of an eclectic set of main characters across the world when, from one day to the next, women turn out to have ‘the power’. That is, there’s an organ that only women have that has suddenly become active with which, while it does not make girls and women physically stronger than men, they can hurt or kill men with or rape them through administering an electrical surge at a certain place. This obviously affects the status quo of the patriarchal societies across the world, and the girls and women respond differently on the new powers gained based on both their personal background and how bad it was for them in their subculture and country. The men respond differently to it as well. Without revealing too much, it could be categorised in the ‘futurist fiction for feminists’, sort of, as it’s also about ‘what if for millennia sexism was reversed?’ and ‘what if it were to be reversed now and it’s payback time?’. The answers that the author came up with make for useful reading, and perhaps also contemplation, for both women and men. Whether you think at the end it’s a dystopian novel, fanciful daydreaming, futurist fiction for feminists, a thriller, a useful mirror to the current society we live in, or stick another label to it—an opinion you’ll have of it :).

If these books don’t interest you, then perhaps one of the previous ones I posted about in 2012, 2013, 2014, 2015, 2016, and 2017 just might (I’m an omnivorous reader).

Water scarcity in Cape Town—not the first city and the new levies are fine

I very well remember the water shortage in Lima when I was there in mid 1996-early 1997, so I already played with the idea of writing a post on the water shortage in Cape Town with the aim to scare some people here what it’s like when the water runs out and to provide some more suggestions to save water or stay clean with less water. For instance, you can greatly reduce the need for washing your hair if you shave it off, or let it grow and put it in one or more braids. Buy more underwear now if you can, because fishing them out of the unwashed laundry basket for reuse is gross (whether to wear them again inside-out or not). A difference then there in Lima with now in Cape Town, is that a lot of people relied on bottled water to drink already, whereas Cape Town water is (still) potable, so there is no real bottled-water logistics here, at least not to the same extent. On logistics: ‘Day Zero’ is the day when the taps run dry entirely and some 200 water distribution points will be the only source of water for 4 million people in the city. The current ‘Day Zero’ estimate is around April 22, give or take a few days depending on the scenario. There’s a nice app by Piotr Wolski where you can run through alternative scenarios to estimate Day Zero.

What pushed me to write a post is one nuisance about the claim that Cape Town is the ‘first major city in the world’ that faces this problem [1]—she isn’t!—and a real annoyance with a recent UCT News article by Kevin Winter on the planned water levy [2]. (The latter indirectly also relates to another irritation I have, in that it is mainly the affluent in leafy suburbia who keep using water excessively and think that somehow running out of water is not going to affect them (lifetime of being privileged, living in a bubble and all that)). So let me discuss both.

Cape Town is not the first major city with a water shortage

Searching now for information on the water shortage in Lima back then is out-crowded on the search engines by the fact that that 8-million (!) huge city has been having so many year-on-year shortages (e.g., a picture of a water distribution point in 2016). Lima is expected to become the first major city to become uninhabitable due to the persistent water crisis; e.g., see what it is like when people are running around to find a litre or two. This is due to less precipitation in the mountains (back then at least) and receding glaciers on the climate side of the issues, and more people in the city, economics, and socio-political issues as the human and systemic dimension. This has worsened over the past decades, where Ioris also lists receding aquifers and degraded catchments, which is blamed on human factors, notably uncontrolled mining, over-abstraction, and untreated effluents [3].

Water rationing back then in late 1996 was by quarter: the poorer quarters got cut off earlier than the richer ones. I rented a room in a lower middle income quarter (Pueblo Libre), and recall the taps running dry (and thus also no flushing the toilet—forget about washing clothes) first at 9pm to come back on in the early morning, then 6pm, then 3pm, 12noon, 9am, and some days nothing; the service came and went. No hay agua. When I didn’t have water anymore at home, the richer quarters still had some, as had the International Potato Center (CIP) where I did a research project on sweet potato. Initially, some people were pretending to play sports at the CIP during lunch hour so that they could have a shower afterward without losing face. At some point when the water outages became more prevalent in most quarters, pretences fell. At a later point, there was no water coming out of those showers there anymore either, nor was there water in the labs anymore, even though the CIP is located in the affluent La Molina district. So yes, eventually also the relatively rich had to do without water, in a society that has already an unequal distribution of resources. The number of foul-smelling people increased. The upside of not being clean yourself either is that then at least you don’t smell the stench of others anymore. This is just one anecdote of what I observed and experienced. Check out Ioris’s paper on Water scarcity and the exclusionary city: the struggle for water justice in Lima, Peru [3] for results from qualitative empirical research from 2009-2013. In short: it’s gotten worse and the problems have become more complex. Relevant for the next section is also its Table 2, which lists data of 12 municipalities: lowest income Villa El Salvador has an average household income of 881.8 PEN, 14.2 cubic metre water p.p., 27.2 water tariff, and they spend 3.1% of their income on water (highest is 4.1%, in low-income Chaclacayo), whereas the figures for highest-income San Isidro are 8303.4 PEN, 29.6 p.p., 68.6 water tariff, and 0.8% of their income is spent on water [3]. Or: the richest use most water and relatively pay the least. 2011 figures state 15.2 litres p.p./day water use by people in Lurigancho-Chosica and 447.5 litres in San Isidro, on average, and large disparities in the cost of water based on one’s socio-economic status [4].

So, Cape Town most definitely is not the first major city with water scarcity issues, nor the first one with a socio-economic and political dimension to it. Apparently, the ‘driest capital’ claim goes to Cairo, with Lima coming in second [5]. As a final note in this section, some 4 billion people have to put up with water scarcity for at least one month per year; more precisely, 71% or 4.3 billion people [6]. Sure, the Western Cape region is firmly in the red in the figures there, but, also, the “Regions with moderate to severe water scarcity during more than half of the year include northern Mexico and parts of the western United States, parts of Argentina and northern Chile, North Africa and Somalia, Southern Africa, the Middle East, Pakistan, and Australia” and “[h]igh water scarcity levels appear to prevail in areas with either high population density (for example, Greater London area) or the presence of much irrigated agriculture (High Plains in the United States), or both (India, eastern China, Nile delta)” [6].

Comments on polemics and facts on Cape Town’s water shortage

I chatted the other day with someone who’s in the water business here in Cape Town and asked his opinion on the shortage. The answer was “It’s very, very, very, bad… And I’m an optimist!”. You probably can find a few articles online that claim it’s all exaggerated; Olivier busts some of those claims [7] and the GroundUp water crisis articles also provide ample investigative news reporting on the dire state of affairs. Fact is, the dam levels on 29 December were at 31.4% and the rainy season will start only in late April (hopefully) or in May and, as mentioned before, Day Zero is expected to be in the second half of April, if everything continues as ‘business as usual’.

In another attempt to change the current ‘business as usual’, a new “level 6” water restrictions came into effect yesterday. Another item may be implemented on February 1, if the Cape Town government gets its way, being an extra water tax proportional to the value of the property where the raised revenue will be used to fund water augmentation schemes. It is this that Winter is whining about in the UCT news article [2]. He’s not the only one: there’s also an ‘Organisation Undoing Tax Abuse’ that claims they’ll sue the national government for it if it goes ahead. Winter speculates that the increase is more because of falling revenue due to lower water use, but he provides no evidence that the extra revenue will be used for something else than the reason stated by the municipality.

Winter argues that residents who have invested in water saving devices are “punished” with the levy and, rather, one should “use the opportunity to encourage this water to be shared with others in need, at a marginal cost”. In other words: the few with sufficient money to spare who invested in such measures (e.g., installing a borehole) should be offered a way to get a quicker return on investment. Trying to make money from an impending disaster. He continues “Non-potable, fit-for-purpose water can be used for flushing toilets, irrigating gardens, topping up swimming pools,…” WTF? He’s still fine with topping up swimming pools, caring about gardens? You shouldn’t have that much excess water from various uses to begin with. If one were to actually use the targeted 87 litres/day or, preferably, less, you will not have excess water. I surely don’t and I’m at about 45 litres/day[1]. Take a short shower instead of diving into the pool and if you swim for exercise then go running or to the gym for a change. Get your garden sorted out with indigenous plants that are already drought-resistant, so you don’t have to water the plants in the first place (or let them die—if it’s cleaning yourself vs. saving imported plants, please let the plants die now and redesign your garden next year).

Then, “it is also time to rethink expensive centralised schemes and the role of local government control in the distribution of water”. Sure, everyone is allowed to have an opinion, but a libertarian anti-government stance is surely not going to help. Read up on Lima as example. Winter goes on “The drought levy appears to send the wrong message. It fails to incentivise local initiatives that will enable access to a local water supply. Neighbourhood-scale water supplies offer a promising alternative.”. The policy target is to reduce water usage across the board. Thus, it makes total sense that the Cape Town government would not want to incentivise such local initiatives, for Winter’s proposal amounts to incentivising water wasters wasting more water by allowing them to make money of the excess water they’re using. The water wasters must reduce their water use so that also they will not have any excess water anymore.

He goes on fantasising if decentralised water systems would work, as if that could be implemented now-now. There’s not even a rough calculation whether such a scenario even might work, let alone if so, how much it will contribute to easing the pressures on the water demand and how much it would cost to implement it all. So, Winter’s proposal is just braai-talk at best, in the most generous and favourable reading of the piece. Oh, and if the reader did not get the message yet: “Property owners will then become the responsible owners of these systems”. So that the rich can become richer by exploiting the poor even more, also when it comes to the very basic necessity for life! Those property owners—the ones who’ll have to pay most levy in particular—aren’t particularly responsible now, neither on the water usage nor on a less unfair wealth distribution, so I don’t see why I should believe Winter’s word that they then would suddenly become “responsible” sharing citizens in his decentralised water system. If ‘leafy suburbia’ were only to have their bubble punctured and would have reduced their water usage substantially already[2], we’d have (had?) sufficient water to make it to the rainy season before Day Zero would be upon us.

You could say, ‘but I know x and y in leafy suburbia who are saving water and they’re nice people’, and I do save too, but I’m willing to pay my bit of the levy, hoping that it hits home that everyone will have to start taking it seriously, and have it invested it in those water augmentation measures for the public good, including more distribution points at least. Do the math: 200 distribution points for 4 million people is 20000 people/day, that’s 4.3 seconds per person/day (24/7 service) that you can tap water to carry home, or worse. Other investment measures should help as well, such as desalination plants under construction, but it is not clear at all whether that will be enough [8].

If the electricity load shedding policy is anything to go by—everyone affected equally—then so will, or should, the upcoming ‘water shedding’ affect everyone equally. Fact is that domestic users are the biggest water users [9], with 15% by business and industry, and only 4.7% by informal settlements in 2015/2016 (checked), and the rich leafy suburbs the most (open data). I would suggest to the Cape Town government that they should turn off the water for a bit to educate the privileged class in the leafy suburbs to teach them the hard way what it will be like if they keep using too much water. They also could take up Lima’s costing plan for water, as is already done with property tax in Cape Town, i.e., charge more for water in those suburbs with higher property values.

Property values are a reasonable indicator of affluence. So if residents in the leafy suburbs keep on using too much, then they surely should cough up at least some of the money for the water augmentation schemes. Not reducing water usage now and not coughing up money for bad behaviour over the past months is bound to result in some unpleasant situations. Have a look again at the video clip from Lima if you must—people at night running on the streets with a bucket, desperate to find a litre. Not to mention the class and race tensions that are already being amplified with the water crisis; the ‘leafy suburbs’ were designated white areas under Apartheid, and not much of the demographics nor of the wealth distribution has changed since then. Little has been written about that, but talk on the ground is going around.


There are issues that can be traced to politics at the local, provincial, and national levels [10]. However, in the context of the article, let me point out that the city and the province has a majority Democratic Alliance—a political party way on the right-end of the political spectrum (very capitalist etc.)—and even they don’t propose the water-spending and money-making-scheme-for-the-rich that Winter proposes. They at least get their facts, run through scenarios, and they probably can count how many votes they’d lose if the majority of the people in Cape Town would have to pay the predominantly rich water wasters to access second-grade water to survive. Having such a politically slanted opinion piece on UCT News is an embarrassment, to say the least, and is counter-productive for managing the water crisis in a manner that will make everyone get through this.



[1] Khan, S. There is a water crisis in Cape Town. Travelers should be prepared (and can help). The New York Times, 27 December 2017. Note: the claim comes from Prof. Anthony Turton, UFS, and has been made before (at least by early December, when a colleague mentioned it as well but could not recall the source). This one was just the most recent article about it that I came across that still propagates the incorrect statement and the outlet has a wide readership.

[2] Winter, K. Cape Town’s drought levy. UCT News, 20 December 2017.

[3] Ioris, A.A.R. Water scarcity and the exclusionary city: the struggle for water justice in Lima, Peru. Water International, 2016, 41:1, 125-139.

[4] Redacción. El agua es un bien escaso que el Perú no sabe administrar. RPP Noticias, 22 March 2017.

[5] Simon, Y. Lima running dry—Promoting water culture in the second driest capital of the world. WorldBank Water and Sanitation Program. Last accessed: 1-1-2018.

[6] Mekonnen, M.M., Hoekstra, A.Y. Four billion people facing severe water scarcity. Science Advances, 2016, 2(2): e1500323.

[7] Olivier, D.W. Cape Town water crisis: 7 myths that must be busted. The Conversation, 7 November 2017.

[8] Jones, A., Geffen, N. Drought: Has Cape Town planned properly for Day Zero? GroundUp, 6 December 2017.

[9] de Lille, P. Drought crisis: bad apples ruining the efforts of many water savers. City of Cape Town, 23 February 2017. Note: more sources and links are available from the GroundUp article by Piotr Wolski, which also contains an analysis on availability of data, and the lack thereof.

[10] Olivier, D.W. Cape Town’s water crisis: driven by politics more than drought. The Conversation, 12 December 2017.

[1] well, the monthly bill yoyo’s between about 30 and 60 litres, as does the one of a colleague of mine, so the guess is that that’s due to rounding in the water meter reading and that the real litre/day use lies somewhere between these figures.

[2] The amount of anecdotes I have are numerous enough to become data. The water usage facts back it up (see further down in the post).