m e i . o r g . u k Curriculum Update Thinking of offering Core Maths from September 2015? MEI and OCR will be running free network events to provide information about our Core Maths qualifications and introduce teachers to the free resources available for teaching them. Would you like to host an event at your school or college? Please see our new Core Maths page for more information. GCSE: Progress 8 measure The DfE has published information about the Progress 8 measure, including how grades from 1-9 GCSEs will be combined with A*-G GCSEs. Click here to view the document on the DfE website. I s s u e What to believe - friends, statistics or politicians? It’s difficult not to know about the upcoming parliamentary election, with every newspaper taking a different angle every day, and with all eyes on this week’s Budget announcement. But when it comes to deciding which way to vote, how do you decide? How many people use statistics to help them to form an opinion? How many base their judgement on personal experience? I revisited this 2013 Telegraph article following the publication of the Ipsos MORI Public Understanding of Statistics Topline Results April 2013. Tom Chivers, the author of the Telegraph article, reported: “One thousand and thirty-four British adults between 16 and 75 were asked to choose between the following statements: Statistics are more important than my own experiences or those of my family and friends in helping me keep track of how the government is doing My own experiences or those of my family and friends are more important than statistics in helping me keep track of how the government is doing Forty-six per cent chose the latter. Just nine per cent chose the former.” Click here for the MEI Maths Item of the Month M a r c h 4 5 2 0 1 5 These figures are rather alarming taking into account the narrow experience of many voters, but, Tom Chivers explains: “The trouble is, of course, that people don't trust statistics because other people use them to hide, rather than illuminate, the truth. Once you've been misled once, you're less likely to trust people again.” While statistics are extremely valuable, they are also notorious for being a means to make false and misleading arguments or claims. Unless we have good access to the data and know how is was obtained, it is important that we recognise that statistics can misrepresent what is going on. In this issue we’ll take a look at how statistics can be used to represent and to misrepresent claims. In this issue Curriculum Update March focus: Misleading statistics Fast and Furious Problem Solving Crash Course: Recursion Site-seeing with... Claire Baldwin Teaching Resources: KS4: Folding and Proof Core Maths: The Parable of the Polygons M4 is edited by Sue Owen, MEI’s Marketing Officer. We’d love your feedback & suggestions! Disclaimer: This magazine provides links to other Internet sites for the convenience of users. MEI is not responsible for the availability or content of these external sites, nor does MEI endorse or guarantee the products, services, or information described or offered at these other Internet sites. Statistics that changed the face of nursing Diagrams transcend language While it isn’t strictly true to say that Florence Nightingale was the first to use diagrams for presenting statistical data, she may have been the first to use them for persuading people of the need for change. You can read more about the evolution of Nightingale’s statistical diagrams on the York University website. Robert Kosara’s blog EagerEyes reflects on the world of information visualisation and visual communication of data. His page: Shining a Light on Data: Florence Nightingale provides useful insight into Florence Nightingale’s use of diagrams to communicate data to decision makers who lacked knowledge of statistics or mathematics. Many of us know of Florence Nightingale as the founder of nursing as a profession, but she was also an accomplished statistician and graph maker. Through her work as a nurse at a British hospital in Turkey in the Crimean War, Florence Nightingale was a pioneer in establishing the importance of sanitation in hospitals. When she left Turkey after the war ended in 1856, the hospitals were efficient and well-run with mortality rates no greater than civilian hospitals in Britain. On her return to Britain Nightingale meticulously gathered data on how soldiers had died, where and why. Through her tables of statistics she discovered that the majority of deaths in the Crimea were due to poor sanitation rather than casualties in battle, or poor food or supplies. Nightingale wanted to persuade the British government of the need for better hygiene in hospitals. She realised though that just looking at the numbers was unlikely to impress ministers, and sought a way to get across her findings using graphics. To show the number of deaths each month and their causes, rather than using a bar graph, Nightingale chose to use a more arresting graphic that allowed for easy comparison across the seasons. For this graphic she used a variation on the modern pie graph. This polar area diagram has come to be known as a “coxcomb.” The circular presentation uses areas to represent the variation in the death rate, instead of the length of radial lines. The blue wedges, representing death by sickness, are far bigger than the red wedges representing wounds. The black wedges measured from the centre represent deaths from all other causes. Click here to view a larger version of Nightingale’s Diagram of the Causes of Mortality in the Army in the East. You can see an animation of this diagram on the Science News website. Click here to view this animation. Clicking on the bar chart tab of the above interactive diagram clearly demonstrates the limitations of using a bar chart to represent the same data. Florence Nightingale made extensive use of this type of diagram to present reports on the conditions of medical care in the Crimean War to Members of Parliament and civil servants who would have been unlikely to read or understand traditional statistical reports. Learn more about Florence Nightingale in Stella Dudzic’s MEI Conference session on Friday 26 June. “If the facts don’t fit the theory, change the facts.” (Einstein) Burt’s impact on educational testing Burt’s belief that educational ability was usually inherited by children led to testing all children in their final year of primary education to see if they had the academic ability to attend a grammar school or if they were better suited to technical or secondary modern schools. It is now widely accepted that it is impossible to measure the proportion of intelligence that results from inheritance and upbringing. The Intelligence Fraud Sir Cyril Burt was a very well known British psychologist and a leader in the development of methods of data analysis. Burt spent much of his career trying to understand the link between heredity and intelligence. He believed that hereditary factors accounted for 85 percent of intelligence and developed a study of twins reared apart to prove it. The papers Burt published on the topic were rarely questioned while he was alive, but shortly after his death, colleagues reviewing his work became suspicious of the study's data. In the early 1950's, Burt published results from studies of identical twins. Correlation coefficients for the IQs varied between monozygotic (identical) twins reared apart and dizygotic (fraternal or non-identical) twins reared together. Burt’s results showed the IQs of identical twins reared apart were much closer than the IQs of nonidentical twins. He concluded that genetic factors were more important than environmental factors in determining intelligence. However, three years after Burt’s death attention was drawn to some apparently puzzling features of his data concerning the inheritance of intelligence. This led to accusations of fraud, the major charge against Burt being that additional data on kinship correlations of IQ, especially for identical twins reared apart, reported to have been gained over the period 1955 to 1966, were fabricated. It appeared that Burt often concealed information on the size of samples and when they were collected. The suggestion was that estimates were adjusted to accord with Burt’s preconceptions. It was also claimed that Burt invented some of his co-workers. Burt's work continues to be controversial and the subject of numerous books and journal articles. You can read more about this controversy in a Human Intelligence article. In his 1991 paper, John Hattie of The University of Western Australia describes the concerns of Leslie Hearnshaw, an established British historian of education who was writing an official biography of Burt. “Hearnshaw concluded that the data which Burt used for his calculations were poor and unreliable, that he made a great many unexplained, careless and inconsistent adjustments to the raw scores of his tests with the results that the figures are quite improbable. He ultimately applied sophisticated statistical techniques to scientifically almost worthless data, with disastrous results.” However, Robert Audley said in a 1993 Times Higher Education article that we should not dismiss all of Burt’s work out of hand: “Although some of the evidence he published in his later years is of doubtful scientific value, the contributions he made during a long professional life remain impressive, and I believe it is misleading to continue to hold him up as the icon of scientific fraud.” Using data in the maths classroom Using Big Data in education Using data in the maths classroom Here are links to some publications, articles and web pages that you may find useful: The new National Curriculum brings a change in emphasis in using data in mathematics. Getting schooled in the ‘noise’: learning about learning using big data UK Big Data boost as Alan Turing Institute opens in London A world full of data: Statistics opportunities across A-level subjects Information is Beautiful: ideas, issues, knowledge, data — visualized! Royal Statistical Society Teaching Resources Significance magazine GCSE students will be expected to interpret, analyse and compare the distributions of data sets, rather than creating or contrasting data. A level students will be expected to use big data sets, learn to use spreadsheets and to draw inferences. AS and A level Mathematics specifications for teaching from 2017 will require students to work with large data sets using technology. Students will also need to be able to use calculators to analyse subsets of the large data set. What could this look like in the classroom and how will it help students understand statistics better? MEI Resources Data Sets The new Data Sets page on the MEI website provides data sets for teachers of statistics to use with their students. Information is given about the data and an indication is given of statistical techniques that may be useful when working with the data set. The Data Sets page lists sources that offer a number of data sets with some information about the data and guidance about which statistical techniques are useful for each data set. Also listed are useful websites for working with real data. Natural history data sets Chris du Feu has kindly made data sets available on the MEI Data Sets page; he has a keen interest in data about birds and slugs. Professional Development Stella Dudzic, MEI Programme Leader for Curriculum and Resources, and Neil Sheldon, RSS Vice-President for Education and Statistical Literacy, will deliver a plenary about Using Technology To Explore Large Data Sets at the MEI Conference in June. Here are some MEI Conference sessions relating to statistics and the use of data: click the link to find out more about the session and the target audience: The new Higher Tier content Teaching S1/Core Maths statistics using graphing technology Statistical insight through simulation on a spreadsheet Statistical insight through data visualisation tools Resources and Investigations: The Normal Distribution and Probability Plots Resources and Investigations: Correlation and Hypothesis Tests Statistical insight through simulation on a spreadsheet Statistical insight through data visualisation tools Don't believe everything you read in the papers Fast and Furious problem solving FMSP Problem Solving posters You can download the set of 6 posters in print-ready PDF format from the FMSP website. MEI and the FMSP will have stands at the upcoming ATM Conference, the MA Conference in April and at the STEMtech Conference & Showcase at the end of April - free posters will be available! Just as we were going to press, a news story was published about the soon to be released film Fast and Furious 7. In a car chase scene in the film, the character Dominic Toretto, played by Vin Diesel, finds himself behind the wheel of a powerful sports car (a Lykan HyperSport) on about the 45th floor of the tallest of the five buildings in the Etihad Towers complex in Abu Dhabi. Toretto decides that he can ‘leap’ the car across the gap into the building opposite. This video shows what happens next. Do you think Toretto could pull this stunt off if it were for real? The answer boils down to a fairly simple maths problem, and as it happens, MEI’s Phil Chaffé was recently teaching in Abu Dhabi. Phil was approached afterwards by a freelance journalist who challenged Phil to make the calculation, based on the following assumptions: The car is a Lykan HyperSport, which weighs 1,400kg. Let’s assume there is enough room in the building for it to reach 100km/h, which it can do in 2.8 seconds. The distance of the jump is about 50 metres. How far horizontally would an object weighing 1400kg travel with an initial velocity of 100km/h, and how many metres would it drop vertically for every metre travelled horizontally? And what is the formula that would demonstrate this? You can read the background to the stunt, see photographs and read Phil’s calculations in Jonathan Gornall’s resulting article in The National, Abu Dhabi Media's first English-language publication. There is a graphic describing the maths behind the problem—click image to view larger version. Charlie Stripp, MEI’s Chief Executive said: “It's excellent to see MEI mentioned In this context, and a really nice application of A level mechanics and mathematical modelling.” Mathematics teachers will be pleased to know that Phil is in the process of producing a set of problem-solving enrichment posters for the Further Mathematics Support Programme, including one about this stunt. These will be available in a few weeks’ time. Crash Course: Recursion A maths and computing puzzle column written by Richard Lissaman This column provides an introduction to the programming language Python using maths puzzles as motivation to learn code! In this month’s column we’ll take a look at an amazingly powerful feature of some programming languages, including Python, called recursion. Take a look at the code on the left of the screengrab below. In the first line we define a function called sumintegers(n). The next two lines are simple, they just say that sumintegers(1) is the value 1. 1) The next line is potentially mind-blowing! The else part of the if statement requires the function to use itself! But we are still in the process of defining the function! Think carefully about what happens when sumintegers(4) is taken. Since 4 ≠ 1, sumintegers goes straight to the else line and so will return 4 + sumintegers(3). Now Python needs to start thinking about sumintegers(3). Again since 3 ≠ 1 this will return 3 + sumintegers(2). Let’s take stock: sumintegers(4) returns 4 + sumintegers(3) and then Python calculates that sumintegers(3) is 3 + sumintegers(2). Python will now work out that sumintegers(2) is 2 + sumintegers(1). But sumintegers(1) is just 1. Piecing all this together sumintegers(4) is dealt with as follows Crash course February problem – solution can be downloaded from the Monthly Maths web page, or click the link above. 4 + sumintegers(3) = 4 + 3 + sumintegers(2) = 4 + 3 + 2 + sumintegers(1) = 4 + 3 + 2 + 1 = 10 Think about this carefully and you should be able to convince yourself that sumintegers(n) is the sum of the first n integers, 1 + 2 + 3 +….+ (n – 1) + n. Crash Course: Python challenges Coding resources Computing At School has produced a new resource to help teachers in England get to grips with the new computing curriculum. QuickStart Computing is a comprehensive, national programme designed to help primary and secondary teachers to plan, teach and assess this brand new subject. Click here to find out more and download resources. Here is another example. The Fibonacci sequence is defined so that the first two terms are 0 and 1 and then any subsequent term is the sum of the previous two. The function fib(n) below returns the nth Fibonacci number. Look how closely the Python function matches the mathematical definition. Problems of the month 1) Adapt the code in the first example above to define a function sumpowers(m,n) which returns the sum of the m th powers of the first n integers, where n and m are positive integers. 2) The first six rows of a mathematical object called Pascal’s triangle are shown here. Each element in the triangle is either 1 (when the number is at either end of a row) or the sum of the two numbers immediately above it (when the number Make it Digital is not at either end). Can you create a function in On 12 March 2015 the Python that takes in a positive integer n and prints BBC launched Make it the first n rows of Pascal’s triangle to the screen? Digital, a major UKwide initiative. WideFor this problem you might find it useful to recall arrays in Python from the last reaching content column. Maybe you can define a function that will produce the nth row of Pascal’s across TV, radio and triangle as an array. Here is a reminder about arrays: online will showcase how Britain has helped shape the To create an empty array in Python called my array use myarray = []. digital world, raise awareness among To add the number 5 to the array use myarray.append(10). This (first) mainstream audiences element of the array is then referred to as myarray[0] and so could be on why digital matters, and inspire younger printed to the screen using print myarray[0]. Further numbers added using audiences to have a myarray.append would then be referred to as myarray[1], myarray[2] and go and get creative so on. with digital technologies. Site seeing with… Claire Baldwin Each month a different member of MEI staff will share a couple of their favourite resources it might be some software, a website, a printable download, a book, etc. This month’s resources are shared by Claire Baldwin, a Central Coordinator for the Further Mathematics Support Programme, which is managed by MEI. Claire has specific responsibility for Higher Education Liaison and Gender Participation in Mathematics within the FMSP. One of my favourite mathematics books in recent years is Professor Stewart’s Cabinet of Mathematical Curiosities by Professor Ian Stewart. The book presents an eclectic mix of classical mathematical puzzles, journeys through the history of famous theorems, and even advice on how to identify a fake coin using a set of scales. I love the lack of chapters or structure and the fact that this miscellany of mathematics originates from a notebook which the author started when he was 14 years old. My favourite puzzle involves placing a long (2m) loop of string over your wrist, putting your hand in your pocket and facing the challenge of removing the string without removing your hand from your pocket (and no, you can’t undo the string!). (Diagram opposite is from IGGY, where you will also find the solution) I have just bought the Claire will be latest book in the delivering a session: series, Professor “The Participation of Stewart’s Casebook of girls in Mathematics Mathematical and Further Mysteries. It contains Mathematics” at the many problems that 2nd Annual you can use in your STEMtech classroom to help Conference & promote critical thinking Showcase on and to demonstrate the beauty of Wednesday 29th April mathematics. at the QEIICC. When working with students applying for degree course in mathematics, I am often asked what different content titles in the undergraduate course guides actually mean. For example, what is ‘analysis’? And what would be studied in ‘linear algebra’? The Further Mathematics Support Programme website contains an invaluable resource, Preparation for Mathematics, to help answer this question. Here, students can see typical undergraduate content of the first year of a degree programme and view a growing number of hyperlinked resources which show how the content links to their study of A level Mathematics or Further Mathematics. Each resource has a number of tasks for students to complete, with fully worked solutions – useful for in-class extension material or independent study. In addition the page has more general advice about preparing to study a mathematics degree including recommended reading and guidance on STEP/AEA/MAT. Core Maths resources Thinking of offering Core Maths from September 2015? MEI and OCR will be running free network events to provide information about our Core Maths qualifications and introduce teachers to the free resources available for teaching them. The events will take place in the afternoon or in twilight sessions and will last approximately two hours. We could run an event at your school or college – as well as the convenience of us coming to you, OCR is willing to pay a small fee to cover your expenses in hosting the event. If you are interested in hosting an event in the summer term, please contact Stella Dudzic by the end of March and we’ll try to schedule it in. Click here to email Stella. New Core Maths teaching and learning resource Core Maths qualifications are designed for students who have achieved grade C or better in GCSE Mathematics, but who do not intend to take AS/A level Mathematics. They enable learners to strengthen and develop the mathematical knowledge and skills they have learnt at GCSE so that they can apply them to the problems that they will encounter in their other level 3 courses, further study, life and employment. In this issue of M4 you will find a Core Maths teaching and learning resource at the end of the magazine, in addition to the Key Stage 4 resource produced by Carol Knights. This has been provided by Terry Dawson, who develops Critical Maths and Core Maths resources for MEI (subscription to which is free). We have provided the Core Maths resource in a PowerPoint format for the teacher to introduce the activity to students, and in a PDF worksheet format to be used as a student handout. Both formats can be downloaded from the Monthly Maths web page. If you or a colleague in another teaching department are planning to deliver Core Maths in your school or college, you may find this resource useful. By registering for the free MEI resources for Core Maths, you will be able to access the MEI Introduction to Quantitative Methods News Forum, where you can share and discuss ideas for using the Core Maths Resources. On this forum there will also be discussions about the MEI/OCR Core Maths problems postcards that will be sent to centres by OCR and also given out at some events attended by MEI. You will need to register for the Core Maths resources to access the discussions. Here’s an example of a Core Maths forum post: Do the top 1% own 50% of the world's wealth? Wealth distribution has been much in the news recently - if you want to know where the figures come from and get some ideas of discussion points to use with students http://fusion.net/ story/39185/oxfams-misleadingwealth-statistics/ is a good place to start. If you would like to subscribe to the Core Maths resources for the academic year 2014-15, please complete the online subscription form. This subscription is free of charge, will run until September 2015 and can be renewed free of charge after that. New classroom resources In the following pages are Key Stage 4 and Core Maths teaching and learning resources: KS4: Representing Data: Florence Nightingale, developed by Carol Knights. Looks at the statistical work of Florence Nightingale and helps students consider different representations and how they can be misleading. Core Maths: The Parable of the Polygons, developed by Terry Dawson. Uses Game Theory to investigate segregation in society. The resources can be downloaded from the Monthly Maths web page. Florence Nightingale Florence Nightingale is well known as the founder of modern nursing, particularly for her work during the Crimean War in the 1850s. She is perhaps less well known for her use of statistics, although it is precisely this that underpinned the changes she instigated within nursing. Florence Nightingale In 1854, Nightingale led a team of nurses that she had trained to care for soldiers wounded in the Crimean war. Death rates were very high, and Nightingale believed that this was largely due to the poor conditions, which included poor nutrition and a general lack of hygiene. She and her team worked to improve diet, sanitation, morale, and general hygiene practices. Florence Nightingale Her experience in Crimea led Nightingale to campaign for improved conditions, and she used statistical diagrams to help display data she had collected to make a more persuasive argument. This short activity looks at the diagrams she created and some alternative representations. Florence Nightingale On the following slide is the most famous of Nightingale’s diagrams and the key text, in case it is difficult to read. Look at the diagrams and spend a few minutes making sense of them. • What do the diagrams show? • What might people misunderstand about the diagrams? The key text: The blue, red and black wedges are each measured from the centre as the common vertex. • Blue: preventable disease • Red: death from wounds • Black: all other causes November 1854: black line shows where deaths from other causes is. October 1854 & April 1855: black and red coincide Understanding the diagrams The area of each wedge represents the number of soldiers who died from the 3 causes. Wedges are overlaid, with blue on the bottom, then black and then red on top. This means that some wedges cannot be seen at all. It also means that it is not possible to see the entire blue wedge at any time. Do you think this might mislead people? Previous diagrams In an earlier diagram, Nightingale had made the radius of a wedge proportional to the number of people in the section. She decided that this could be misleading. Why do you think this was? Previous diagrams How many times larger does each section look compared to the smallest one? Would this be a fair diagram if the sections are to represent 1000, 2000, 3000 and 6000 soldiers respectively? Polar Area diagrams How would you draw a fair diagram to represent 1000, 2000, 3000 and 6000 soldiers respectively? Accurately draw 4 wedges on the diagram to represent this. Other diagrams On the following slides this data set was used to create the statistical diagrams. Comment on them. Blue Red 1 2 January 2 5 February 3 7 March 4 5 April 5 4 May 6 1 June Other diagrams Other diagrams Polar Area diagrams Create a Polar area diagram for the data, similar to the ones that Nightingale created. One colour wedge should consistently overlay the other colour wedge. Which months cause issues in doing this? Polar Area diagrams Jan Feb Mar Apr Jun May Area diagrams Can you also accurately create a diagram so that all parts of the area are visible, i.e. wedges are not overlaid, but radiate outwards? Example shown. Are there advantages to this diagram? How difficult is it to create? Area diagrams Teacher notes: Florence Nightingale This month’s edition looks at the statistical work of Florence Nightingale and then helps students consider different representations and how they can be misleading. It would be helpful to print some colour copies of slide 6 to enable students to look closely at them Much of the early part of this activity involves students thinking and discussing. Slides 12-14 could be missed out with Higher attaining groups. Teacher notes: Florence Nightingale Slides 5-8 The diagrams show that as Nightingale and her team continued to improve hygiene and nutrition, so the rates of death from preventable diseases decreased. This gave weight to Nightingale’s assertion that these were fundamental to nursing care. Potential difficulties with the Polar diagram: • Some wedges are hidden completely • Visually, the blue area could look smaller than it should since it is overlaid with the red and black sectors. • Similarly for the black area being overlaid with the red. • No scale, so although we can see that there are far more blue than black or red, these could be small numbers – which would still be worth reducing, but it would be more persuasive if there were an indication of numbers involved. Teacher notes: Florence Nightingale Slide 9 If the radius is used instead of the area, it looks far more dramatic a difference than it actually is. Where a length is doubled, the area is quadrupled. If a length is tripled, the area is 9 time bigger etc. Slide 10 This diagram emphasises the visual discrepancies created when using the radius instead of the area. On the diagram, the radii are in the ratio 1:2:3:6. This means that the areas are in the ratio 1:4:9:36 Teacher notes: Florence Nightingale Slide 11 Copies of the sheet ‘Polar Area Diagrams’ can be used, or students can construct the diagrams for themselves. 12 sectors are shown, representing the 12 months of the year that Florence Nightingale used. The number of soldiers should be proportional to the area of the sector. Area for 2000 soldiers = 2 x area for 1000 soldiers π(R2)2 = 2π(R1)2 (R2)2 = 2(R1)2 The radii should be in the ratio 1: √2 : √3 : √6 Approximately 1 : 1.4 : 1.7 : 2.4 A radius of 2cm for the first one will fit in the outlines given. Teacher notes: Florence Nightingale Slides 12 -14 The comparative and component bar charts: Both of these have scales, so it is easy to ascertain values. It is possibly a little easier to ascertain proportions from a component bar chart, and a little easier to see trends in the individual items with a comparative bar chart. Pie charts: The data have to be shown on two pie charts in order to compare. It isn’t clear whether these are drawn to the same scale. No scale given so the viewer doesn’t know how many people the charts represent. They do give a good sense of proportion. Teacher notes: Florence Nightingale Slides 15-16 Assuming that a radius of 1cm is used for 1: January February March April May June Blue 1 2 3 4 5 6 Radius 1.00 1.41 1.73 2.00 2.24 2.45 Red 2 5 7 5 4 1 Radius 1.41 2.24 2.65 2.24 2.00 1.00 If red is drawn first and then blue is laid on top, the issues arise when the blue radius exceeds the red, i.e. for May and June. If blue is drawn first and then red is laid on top, issues arise for Jan, Feb, March, and April. Teacher notes: Florence Nightingale Slide 17-18 Assuming that the blue is inside and the red is outside, an additional calculation is required to find the radius for the red section. Since the outside of the red section encompasses both red and blue, find the total. The red area is the difference between the total and the blue. January February March April May June Blue 1 2 3 4 5 6 Radius 1.00 1.41 1.73 2.00 2.24 2.45 Red 2 5 7 5 4 1 Red + Blue Radius 3 1.73 7 2.65 10 3.16 9 3.00 9 3.00 7 2.65 The advantages of this representation are that the whole of each colour is visible and it is easier to compare the overall totals. Acknowledgements Florence Nightingale Photograph and information from http://en.wikipedia.org/wiki/Florence_Nightingale#Crimean_War Accessed 10/3/15 Polar Area Diagrams MEI is a registered charity, number 1058911 Core Maths: teaching and learning resource Using Game Theory to Investigate Segregation in Society Parable of the Polygons “Parable of the Polygons” is a website which uses apps to explore how areas of cities can become segregated. Parable of the Polygons • The site uses a mathematical model to show that small individual biases can lead to a large collective bias. • This activity encourages you to think about the mathematical model underlying the apps. Parable of the Polygons • The starting assumption is that there are two types of individuals (squares and triangles). • Each prefers being in a mixed neighbourhood but is unhappy if too many neighbours are different. Parable of the Polygons • Use the link http://ncase.me/polygons and work through the site. • Using a series of apps, you will start to build an understanding of how certain parameters may result in segregation. The underlying message • Take some time to experience the model in action and ponder the underlying message from the site. • Give some thought to the assumptions made in constructing the different apps. How might these assumptions limit any conclusions made? Percentage of alike neighbours • By filling the surrounding spaces with either squares, triangles, or empty spaces, we arrive at the percentage of alike neighbours. How does the app measure the percentage of alike neighbours? Percentage of alike neighbours • For example consider a square near the centre of the large grid, see the diagram below. • By filling the surrounding spaces with either squares, triangles, or empty spaces, we arrive at the percentage of alike neighbours. Percentage of alike neighbours Are all percentages possible? Explain your answer. Percentage of alike neighbours • Consider how the possible values for the percentage of alike neighbours may change depending on the shape’s position. • You could start by examining a square in one of the corners of the large grid, for example (A) in the diagram below. Percentage of alike neighbours • As you did in the previous example, work out all the possible values for the percentage of alike neighbours. Parable of the Polygons • Now try a square along one of the edges of the large grid, for example (B). Percentage of alike neighbours • Compare the possible percentages you have just obtained for (A) and (B), to the percentages you previously obtained for a square in the central section (C). Percentage of alike neighbours • Assume the simulation was run many times, with the same setting. • Which of the three squares considered above (A, B, or C) , would you expect to move more frequently on average? Percentage of alike neighbours • The screenshot below suggest that there is 56% segregation: Percentage of alike neighbours • How is this figure calculated? • Is this a good way to measure segregation? Percentage of alike neighbours • The initial problem starts with both shapes having the same requirements, that is, that at least 1/3 of their neighbours need to be like them for them to be happy. • On the second app, shown in the next screen shot, you are allowed to change this figure of 1/3 ≈ 33% to other values to investigate its effect on the level of segregation. Percentage of alike neighbours • Is there a maximum level you can set for this figure beyond which a solution becomes impossible? Explain why. Percentage of alike neighbours • How about if the shapes showed different levels of preference? • For example would it be possible for a solution where squares required 75% to be alike, whilst triangles would be happy with 1/3? What constraint does this place on the settings? Wrapping Up Cartoon by Vi Hart Teacher notes: Parable of the Polygons Before using this resource with your students you will want to check to ensure that you are comfortable with them viewing the content on the website and the underlying messages expressed at the end, under ‘Wrapping up’. You may find the apps work better in some browsers than others – they work in Google Chrome. Teacher notes: Parable of the Polygons Game theory is a branch of applied mathematics which is used in economics, sociology, psychology and biology. It deals with mathematical modelling of strategy and behaviour in situations where the decisions which individuals make are affected by what others might do. The 2001 film A Beautiful Mind was based on the life of John Nash who won the Nobel prize for economics for his work on game theory. Mathematical Detail Slides 10-15 Are all percentages possible? No. Looking at a position in the middle of the ‘town’ each shape has 8 neighbours. Therefore there can be 0, 1, 2, 3, 4, 5, 6, 7 or 8 neighbours, of whom various numbers can be alike. The table on the following slide gives the possibilities and the percentages. % (to 1%) No. of alike neighbours 1 2 3 4 5 6 7 No. of neighbours 1 100 2 50 100 3 33 67 100 4 25 50 75 100 5 20 40 60 80 100 6 17 33 50 67 83 100 7 14 29 43 57 71 86 100 8 13 25 38 50 63 75 88 8 100 Mathematical Detail Slides 10-15 Are all percentages possible? On an edge there are up to 5 neighbours. In a corner there are up to 3 neighbours. Mathematical Detail Slide 18 How is segregation calculated by this App? It looks as if it is the average of the ‘like neighbours’ for all of the shapes. The advantage of this is that ‘partial segregation’ is included. An alternative would be to look at how many shapes had no like neighbours at all. In this case there are 126 out of 322, which is 39% of shapes completely segregated. Acknowledgements • http://ncase.me/polygons • https://www.idlethumbs.net/forums/topic/9815parable-of-the-polygons • https://gbark.wordpress.com/2014/12/12/reblogparable-of-the-polygons • https://twitter.com/vihartvihart Accessed 11/03/2015 Using Game Theory to Investigate Segregation in Society Teacher notes Before using this resource with your students you will want to check to ensure that you are comfortable with them viewing the content on the website and the underlying messages expressed at the end, under ‘Wrapping up’. Game theory is a branch of applied mathematics which is used in economics, sociology, psychology and biology. It deals with mathematical modelling of strategy and behaviour in situations where the decisions which individuals make are affected by what others might do. The 2001 film A Beautiful Mind was based on the life of John Nash who won the Nobel prize for economics for his work on game theory. MEI is a registered charity, number 1058911 Using Game Theory to Investigate Segregation in Society “Parable of the Polygons” is a website which uses apps to explore how areas of cities can become segregated. You may find the apps work better in some browsers than others – they work in Google Chrome. The site uses a mathematical model to show that small individual biases can lead to a large collective bias. This article encourages students to think about the mathematical model underlying the apps. The starting assumption is that there are two types of individuals (squares and triangles), each prefers being in a mixed neighbourhood but is unhappy if too many neighbours are different. Use the link http://ncase.me/polygons/ and work through the site. Using a series of apps, you will start to build an understanding of how certain parameters may result in segregation. Take some time to experience the model in action and ponder the underlying message from the site, then give some thought to the assumptions made in constructing the different apps and how this may limit any conclusions made. MEI is a registered charity, number 1058911 Here are a few questions intended as prompts: How does the app measure the percentage of alike neighbours? For example consider a square near the centre of the large grid, see the diagram below. By filling the surrounding spaces with either, squares, triangles, or empty spaces, we arrive at the percentage of alike neighbours. Are all percentages possible? Explain your answer. Consider how the possible values for the percentage of alike neighbours, may change depending on the shape’s position. You could start by examining a square in one of the corners of the large grid, for example (A) in the diagram below. As you did in the previous example, work out all the possible values for the percentage of alike neighbours. Now try a square along one of the edges of the large grid for example (B). Compare the possible percentages you have just obtained for (A) and (B), to the percentages you previously obtained for a square in the central section (C) A C B Assume the simulation was run many times, with the same setting. Which of the three squares considered above (A, B, or C) , would you expect to move more frequently on average? MEI is a registered charity, number 1058911 The screenshot below suggest that there is 56% segregation: How is this figure calculated? Is this a good way to measure segregation? The initial problem starts with both shapes having the same requirements, that is, that at least 1/3 of their neighbours need to be like them for them to be happy. MEI is a registered charity, number 1058911 On the second app, shown in the screen shot below, you are allowed to change this figure of 1/3 ≈ 33% to other values to investigate its effect on the level of segregation. In the screenshot below the condition for moving is set to “I’ll move if less than 50% of my neighbours are like me” Is there a maximum level you can set for this figure beyond which a solution becomes impossible? Explain why. How about if the shapes showed different levels of preference, for example would it be possible for a solution where squares required 75% to be alike, whilst triangles would be happy with 1/3? What constraint does this place on the settings? MEI is a registered charity, number 1058911