'How can we estimate the mass of the atmosphere?' Oxford interview questions explained

 The questions have been released just after of the deadline day for students to apply to study at Oxford University next year (15 October). Students applying to study Geography might be asked to talk about how the composition of the atmosphere allows us to calculate its weight, while candidates for Music might be probed on how the ways in which we listen to music affects how we experience it. 

'We emphasise in all our outreach activity that the interview is primarily an academic conversation based on a passage of text, a problem set or a series of technical discussions related to the course students have applied for,' says Dr Samina Khan, Director of Admissions and Outreach at Oxford University. 'But interviews will be an entirely new experience for most students, and we know many prospective applicants are already worried about being in an unfamiliar place and being questioned by people they have not met – so to help students to become familiar with the type of questions they might get asked we release these real examples. We want to underscore that every question asked by our tutors has a purpose, and that purpose is to assess how students think about their subject and respond to new information or unfamiliar ideas.

'No matter what kind of educational background or opportunities you have had, the interview should be an opportunity to present your interest and ability in your chosen subject, since they are not just about reciting what you already know. Tutors want to give students a chance to show their real ability and potential, which means students will be encouraged to use their knowledge and apply their thinking to new problems – with tutors guiding the discussion to ensure students feel comfortable and confident. They are an academic conversation in a subject area between tutors and students, similar to the undergraduate tutorials which current Oxford students attend every week.'

Dr Khan adds: 'It's important to remember that most interviews build on material students will have encountered in their studies or touch on areas students mention in their personal statements. Most commonly tutors will provide candidates with material to prompt discussion – for example a piece of text, an image, or a sample experiment whose results they are asked to consider. It is often best to start responding by making very obvious observations and build up discussion from there – solving the problem quickly is less important than showing how you use information and analysis to get there.

'We know there are still misunderstandings about the Oxford interview, so we put as much information as possible out there to allow students to see the reality of the process. We now have mock interviews online, video diaries made by admissions tutors during the interview process, and lots of example questions to help students to familiarise themselves with what the process is – and isn’t – about.'

Here are some sample questions:

Subject: Medicine / Biomedical Sciences
Interviewer: Chris Norbury, The Queen's College

Q: The viruses that infect us are totally dependent on human cells for their reproduction; is it therefore surprising that viruses cause human diseases?

Chris: Like most good interview questions, this could be a starting point for any number of interesting conversations. Most candidates will have a reasonable understanding that viruses are essentially parasitic genetic entities, but the interviewers are not really looking for factual knowledge.

In a tutorial-style discussion, strong candidates will engage with the paradox that viruses need us for their own reproduction, and yet cause us damage. They might point out that some of our responses to viral infection (such as sneezing) favour the spread of the virus. The interviewer might steer the discussion towards viral infections associated with high mortality, and the idea that any virus that killed off its host entirely would run the risk of extinction – unless it could infect other host species too. Candidates may have come across examples of viruses that jump from non-human animals to human hosts in this way.

We might then ask if the candidate considers it possible that there are viruses that infect humans and reproduce successfully, but do not cause any disease. How might we go about finding and characterising such viruses? These questions probe selection criteria including problem-solving, critical thinking, intellectual curiosity, communication skills, ability to listen and compatibility with the tutorial format.

Subject: Music
Interviewer: Laura Tunbridge, St Catherine's College

Q: What are the different ways in which you listen to music? How does that change the way in which you think about what you're listening to?

Laura: Music interviews often have several parts: there may be questions about your interests or on broad topics, and many colleges will give a reading and/or a short piece of music to look at beforehand, which you will be asked questions about. Some colleagues play music in the interview and, similarly, ask what your thoughts are about it. The point of all this isn't to find out what you don't know but to get a sense of how you read a text or understand a piece of music, and how you think through issues or material. We are very much aware that the types of music people play and care about are varied and the course itself covers a wide range, from global hip hop to Mozart, medieval song to sound art. It's not a question, then, of liking the right stuff but of finding out how curious you are, and how well you can apply what you already know to something new.

Standalone questions like this one, are more unusual, but suggest the kinds of topics that might be used to prompt discussion. The question allows students to use their own musical experiences as a starting point for a broader and more abstract discussion about the different ways people consume music, the relationship between music and technology, and how music can define us socially. There might be follow-up questions about whether students think a particular way of listening has more worth the others, for example. It could also prompt other discussions; for example, we tend in Western Europe to be silent in concert halls: why might that be and what is the effect? Does it encourage a certain kind of attentiveness and respect? Might it put some people off? What would be effect of, say, clapping between movements of a symphony to your understanding of how the music works?

I might also expect to discuss whether particular types of music suit being listened to in particular ways; whether listening on headphones changes the way you experience what's going around you; and what makes some soundtracks better than others. We are interested in probing their understanding of music and its contexts, so thinking about how you share music with others and how the environment in which you listen to music affects the way you experience it – if you hear the same tracks live, at a festival or concert, what factors change how you hear and think about the music? The study of music is about more than just examining composed works, and a question like this gets at that aspect of the course.

Subject: Chemistry
Interviewer: Martin Galpin, University College

Q: How many different molecules can be made from six carbon atoms and twelve hydrogen atoms?

Martin: This question gives candidates an opportunity to demonstrate a wide understanding of chemistry and there is no simple, immediate answer.

Most candidates would start by drawing some molecules to construct some that satisfy the requirement of six carbons and twelve hydrogens. If the candidate gets stuck, the interviewer may ask them to explain how many bonds they'd expect each carbon and each hydrogen to form. This part of the interview tests candidates' familiarity with different kinds of molecules, their ability to visualise molecules in three dimensions and then draw them, and their ability to decide if two differently-drawn molecules are actually equivalent. During this process, the interviewer would also be looking at how well the candidate responds to prompting.

After a few minutes, the interviewer may use the question to move the discussion toward concepts such as chirality, cis-trans isomerism, ring strain, and isotope effects. Candidates may not have heard of these before, which is fine and to be expected; the interviewer wants to see how quickly the candidate picks up new concepts and whether they can offer plausible explanations for them. The interviewer might finish the discussion with a rather more difficult question, such as 'is a molecule only stable if all the carbons form four bonds?', thus challenging what is taught at school and getting the candidate to think critically about the nature of a chemical bond.

Subject: Theology and Religion
Interviewer: Peter Groves, Worcester College

Q: Is religion of value whether or not there is a God?

Peter: This is a question we would hope any candidate for Theology and Religion would enjoy answering. It raises a number of issues for them to explore. What is our definition of religion, and how fluid is that definition? What do we mean by value, and how might it be measured? Are the effects of religion in the past as important as its consequences in the present?

A candidate might also want to ask what we mean when we say 'there is a God?' Is affirming this statement enough, or should religious or theological enquiry be more specific – is talk of God in the abstract as helpful as discussion of particular religious ideas or texts? How would we construct a case for the value of religion in the absence of belief in God?

A good answer could engage with one or more of these problems, and we would hope in conversation develop further questions. For example, can we adjudicate competing claims in conversations such as these? Is a worldwide religion such as Christianity or Islam intrinsically more or less valuable because of its number of adherents? Do ethics or aesthetics have a part to play: can I claim religious ideas have value if they inspire great art or music or poetry? Who gets to decide what is great? Does religion affect this decision?

All these possible questions represent directions in which the conversation might go – none is particularly wrong or right, but strong candidates will see a number of different routes available for them to explore, and could choose whichever interested them most.

Subject: Earth Sciences
Interviewer: Conall MacNiocaill, Exeter College

Q: How can we estimate the mass of the atmosphere?

Conall: This question can be addressed in variety of ways and addresses several of our selection criteria: an aptitude for analysing and solving a problem using a logical and critical approach; lateral thinking and hypothesis generation; the ability to manipulate quantities and units; and the ability to apply familiar concepts (pressure, force etc.) to unfamiliar situations.

Candidates often like to start off by thinking about the composition of the atmosphere, and how we might know that, what its density is, and then to ways of estimating its volume. We look to see if there are ways of simplifying the problem: for example, could you treat the Earth and atmosphere as a sphere slightly larger than the Earth and subtract the volume of the Earth from the larger sphere to get a volume for the atmosphere? The difficulty with this approach often lies with determining where the atmosphere ends and how the density might vary with altitude, how applicable concepts like the ideal gas law are in these circumstances, and these are uncertainties that we might explore in a discussion.

An alternate approach is to see if there are properties of the atmosphere that we can observe at the surface that might enable us to estimate the mass. One such property is atmospheric pressure, which is a force per unit area. The force can also be described as a mass multiplied by an acceleration, which on Earth is the acceleration due to gravity. Hence, if we have some idea about atmospheric pressure we can calculate the mass pressing down on a unit area. If we can estimate the total surface area of the earth (approximated by the surface area of a sphere) we can therefore calculate the total mass of the atmosphere.

Subject: Earth Sciences
Interviewer: Roger Benson, St Edmund Hall

Q: Tell me what this rock looks like.

Roger: For this question, you are given a hand sample of rock to examine, and are asked to describe what you see. In the second part of the question, you are asked to suggest how the rock formed, and why it looks the way it does (it is made of crystals of several different types, and the types of crystal vary in their average size).

This question does not rely on pre-existing knowledge of geology or rocks. In fact, what we are interested in is whether the candidates can make accurate and critical observations (what does the rock look like?) and are able to interpret the meaning of those observations using their knowledge of physical and chemical processes (reasoning ability: aptitude for analysing and solving problems using logical approaches). As with many of our questions, we don't want candidates necessarily to tell us the 'right' answer straight away. We want to see that they are motivated, and keen to engage with the topic. We don't want to intimidate or overwhelm the candidates with difficult questions that they haven’t encountered before. But we do want to see that they can get to grips with new information and use it in their reasoning. So we often provide suggestions and small questions that help to guide the conversation at various points.

In the first part of the question, when describing the rock, we want candidates to organise their observations, so they have some structure. For example, the rock is made of crystals, some of which have well-defined shapes. The crystals vary in colour and size, and probably represent different chemical compositions (different minerals). The smaller types of crystals generally have less well-defined edges.

In the second part of the question, we want to see that candidates can use their knowledge of crystal formation – from GCSE and possibly A-level – to interpret why the rock appears as it does. The crystals indicate that the rock formed by crystallisation of molten rock from a liquid to a solid. Some crystals might be larger because they took longer to form. Crystals with poorly-defined shapes may have formed last, fitting into whatever space was available at the end of the process. These observations can be used to discuss the history of cooling of molten rock.

Subject: History
Interviewer: Sian Pooley, Magdalen College

Q: What can historians not find out about the past?

Sian: The aim of this question is to encourage candidates to think critically, creatively and comparatively about how historians know what happened in the past. I would use this sort of open question to allow a candidate to talk about the availability of historical evidence in whatever time period, place or theme interested them from their school-work or wider reading. For instance, a candidate might start off by saying that they had been studying Tudor England and historians don't know much about the lives of the poor because they were less likely to be able to write. Given these lower levels of literacy, we could then talk about what sources historians can use to learn about the lives of the majority of the population in sixteenth-century England. This would require the candidate to think creatively about alternative sources (and their drawbacks), such as, for instance, criminal court records in which people who could not write were required to give oral testimony as witnesses.

Historians are always interested in explaining continuity and change over time, so I might then ask the candidate to compare what historians can know about Tudor England to another time period or place that interests them. For instance, if they had also studied the USA during the Depression, I might ask the candidate whether the gaps in historical evidence are different in interwar America. By thinking comparatively across four hundred years and in different continents, a candidate might be able to draw some thoughtful conclusions. They might want to think about how structures of power have altered over time or about how social norms for what can be recorded and kept in archives have changed. This is the sort of conversation that no candidate could predict in advance. The hope is that the discussion allows candidates to show their understanding of, and enthusiasm for, history, and – most importantly – their ability to think independently, flexibly, and imaginatively about the past.