Below is a list of things I have read and found interesting and have helped me develop as a teacher. I’ve been collecting them over the last year or so and tried desperately to keep them in order. This is a work in progress and I’m going to try and update it when I can. I’ve marked everything that I think is super important with a * so you can ctrl+f for it. I’ve tried to keep my summaries as short as possible – the individual pieces will speak for themselves. You will note that I have avoided books too. This is because I don’t really find the time to sit and dedicate time to full books, I prefer to read stuff on the go, in the little snippets of time I find for myself here and there.
This is mainly a list for my own benefit. If anyone else finds it useful I would be more than happy. And if you have something I’ve missed please let me know.
You can ctrl+f topics as:
What makes great teaching?
Direct Instruction/Discovery Based Learning
Knowledge and Skills
Meta-Syntheses and Policy
Pupil Premium and Closing the gap
The categories are loose so if you’re looking for something else just search your key word – chances are good there will be something here on it. I’m also aware that some thing deserve their own section but this is just how the list grew so I mean no value statements by the headings.
What makes great teaching?
*The best introduction to the research as it stands as of 2014. A really important read that covers a lot of material and can lead in many different directions. Also explains what things don’t work (e.g. discovery based learning)
The above was written partly by Professor Rob Coe. He has done a lot of really important work and one of the main themes of the above is whether or not you can even tell what great teaching looks like. See his further piece here. http://18.104.22.168/blog/414/
Here is Nick Rose’s 7 pillars of classroom practice involving his curated list of further reading.
I’ve tried to categorise my links below so that the aspects of “great teaching” are easier to find.
*Daniel Willingham incredibly important piece on how the brain actually works: http://www.aft.org/sites/default/files/periodicals/WILLINGHAM%282%29.pdf. This is based on his book “Why don’t students like school” which is blooming brilliant.
*Deans for Impact: http://deansforimpact.org/pdfs/The_Science_of_Learning.pdf
*The legendary Rosenshine (2012) paper which is very clear on how to teach effectively https://www.aft.org/sites/default/files/periodicals/Rosenshine.pdf
Basically anything by The Learning Scientists. Most notably their stuff on effective study strategies http://www.learningscientists.org/
Learning about Learning: http://www.nctq.org/dmsStage/Learning_About_Learning_Report
The limits on working memory: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2864034/
Learning versus performance – what actually is “learning?”: http://bjorklab.psych.ucla.edu/pubs/Soderstrom_Bjork_Learning_versus_Performance.pdf (http://pps.sagepub.com/content/10/2/176.abstract) (https://www.youtube.com/watch?v=MMixjUDJVlw) If the above link doesn’t work try this https://teaching.yale-nus.edu.sg/wp-content/uploads/sites/25/2016/02/Making-Things-Hard-on-Yourself-but-in-a-Good-Way-2011.pdf
This is an amazing treasure trove of detail and references from the Bjork’s lab in the states
Organizing Instruction and Study to Improve Learning http://ies.ed.gov/ncee/wwc/practiceguide.aspx?sid=1
Daniel Willingham on teaching to how most students learn instead of differentiating: http://www.ascd.org/publications/educational-leadership/feb12/vol69/num05/Teaching-to-What-Students-Have-in-Common.aspx
Dual coding/Multimedia instruction: the Rosenshine piece above is great at summarising how to make all of these findings relevant in your classroom. Another very important piece on the use of both auditory and visual processing in instruction is here http://homepages.gac.edu/~dmoos/edtech/introtomultitheory.pdf
*A good dose of humility and understanding that teachers are not cognitive scientists is also important. See here for Sue Gerard’s critique of Michaela
There is an outstanding list of seminal papers to be read on Paul Kirschner’s blog here
Here is a very good long-read by Clare Sealy covering all of the basics of cognitive science
Direct Instruction/Discovery based Learning
*One of the most heavily cited pieces available on Instruction models vs. discovery models. This is a classic and a must read http://cogtech.usc.edu/publications/kirschner_Sweller_Clark.pdf
One of the authors of that piece has a lengthy interview here where he also references the genesis of the 2006 piece https://www.researchgate.net/publication/284019119_An_Interview_with_Richard_E_Clark
They followed up with an article in this journal http://www.aft.org/sites/default/files/periodicals/ae_spring2012.pdf (this journal edition also contains the Rosenshine piece linked above and a long piece by Pasi Sahlberg on the Finnish system. It also has another piece by Willingham about educational disadvantage.)
A lot of the evidence for direct instruction comes from Project Follow Through which looked at a number of teaching methods. Not only did it help students learn the material better but their affective scores (enthusiasm/motivation etc) were also increased. So anyone who says it is “boring” is in contradiction with the evidence. See here https://pragmaticreform.wordpress.com/2013/02/02/direct-instruction/ and here https://fhss2.athabascau.ca/html/387/OpenModules/Engelmann/theory.shtml
PISA 2015 report on science shows a negative correlation between science performance and “enquiry based instruction.” The strongest negative correlation is associated with increased practical and hands on work. My theory for this is that teachers assume that by having done a practical students have learned something, when in fact this is highly unlikely. See Pg 63 and on from the link. http://www.keepeek.com/Digital-Asset-Management/oecd/education/pisa-2015-results-volume-ii_9789264267510-en#page76
Most of the above was influenced by Greg Ashman, and his work on Pisa has been fantastic https://gregashman.wordpress.com/?s=pisa
Knowledge and skills
Knowledge is important. Without facts your brain doesn’t work as well at digesting new information and solving problems. There are those who would have you believe that in the age of Google and Wikipedia you don’t need expansive and deep knowledge. They are wrong.
*This is a really great piece tracing the history of how domain specific knowledge and domain general knowledge (i.e. “skills”) have been approached within psychology. It also discusses the difference between biologically primary and biologically secondary knowledge. Long, but excellent. http://andre.tricot.pagesperso-orange.fr/TricotSweller_revised.pdf
I really enjoyed Tom Sherrington’s post on the subject and especially his thoughtful reflection on how he has changed as a practitioner.
On critical thinking: http://www.aft.org/sites/default/files/periodicals/Crit_Thinking.pdf
Content is King – Tom Bennett: https://www.tes.com/article.aspx?storyCode=6389557
Greg Ashman with links: https://gregashman.wordpress.com/2016/04/04/new-south-wales-government-promotes-unproven-educational-fad/ Ashman is a warrior against Dewey-inspired “progressive” education and all of his pieces are well-researched and feature extensive links. See also https://gregashman.wordpress.com/2016/05/05/teachers-of-australia-there-is-another-way/ and https://gregashman.wordpress.com/2015/09/11/faq-direct-instruction/ for more links
“Thinking Skills” are clearly not a thing: http://chronicle.com/blogs/ticker/yes-colleges-do-teach-critical-thinking-skills-study-finds/105930
Daisy Christodoulou on the history aptitude test: https://thewingtoheaven.wordpress.com/
More findings which show the importance of domain specific knowledge, here regarding “digital literacy” http://www.sciencedirect.com/science/article/pii/S0160289616301295
David Didau on Sugata Mitra and core knowledge with lots of important links http://www.learningspy.co.uk/myths/is-it-just-me-or-is-sugata-mitra-an-irresponsible-charlatan/ (see also http://donaldclarkplanb.blogspot.co.uk/2015/10/mitras-sole-10-reasons-on-why-it-is-not.html for specific takedown of Mitra)
Fascinating interview dealing with a 94 year old physicist and issues of scientific creativity. There is also a link to this fascinating piece showing that the highest value patents are designed by older scientists.
Very interesting report here on whether extra computing code classes boosts computational thinking. Interestingly, it doesn’t, but the authors do not seem able to accept this finding and say that this is because computational thinking is already being improved by the normal computing curriculum in school.
Whenever anyone posts a classic “facts are outdated” type article make sure you respond with this by Willingham about why Google is not enough.
Nice recent article here about far transfer – does learning music or chess lead to cognitive benefits in unrelated fields? No.
Dylan Williams wrote an incredibly influential document on assessment which led to the AfL movement: https://weaeducation.typepad.co.uk/files/blackbox-1.pdf
*I have never been convinced by AfL due to the performance vs. learning conundrum: http://www.learningspy.co.uk/myths/afl-might-wrong/
See Williams’ response here http://www.learningspy.co.uk/assessment/dylan-wiliams-defence-formative-assessment/
Here is a blog I recently found and really like with his take on it https://furtheredagogy.wordpress.com/2015/09/26/formative-assessment-is-it-a-silver-bullet/
This is a good review of the evidence on feedback which, despite what people say, is highly mixed. http://www.learningspy.co.uk/assessment/why-feedback-fails/
Cool mythbusting piece here by Ben Wilbrink about assessment generally
I recently discovered this very interesting guide to setting whole school assessment policies. Includes a very important discussion of validity and reliability
Dylan Wiliam has written a history of assessment here
The tide is slowly turning against marking. Ofsted have made their position pretty clear: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/463242/Ofsted_inspections_clarification_for_schools.pdf
Sean Harford, director of Ofsted: https://educationinspection.blog.gov.uk/2016/11/28/marking-and-other-myths/
Government working party on marking: https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/511256/Eliminating-unnecessary-workload-around-marking.pdf
EEF marking review – tl;dr “mark less but mark better.” https://educationendowmentfoundation.org.uk/evidence/evidence-on-marking/ along with detailed takedown of their conclusions https://farrowmr.wordpress.com/2016/04/29/eef-marking-review/
David Didau: http://www.learningspy.co.uk/featured/why-i-like-tick-n-flick/ and associated click throughs
Michaela school use whole-class feedback approaches which are discussed in a great many places including here https://pragmaticreform.wordpress.com/2015/10/31/marking-is-a-hornet/. These are becoming more popular due to MCS’s massive online presence.
Dylan Williams on feedback here and in other places http://www.dylanwiliamcenter.com/is-the-feedback-you-are-giving-students-helping-or-hindering/
Yellow box method a la teacher toolkit: http://www.teachertoolkit.me/2016/03/20/marking/
Greg Ashman on Book Looks with links https://gregashman.wordpress.com/2015/11/26/is-book-sampling-valid/
Meta-syntheses and policy
Education policy is more often than not driven by ideology rather than facts. Politicians who have no experience of teaching go off to some other country and come back proposing a new magic bullet. It’s easy pickings because you can never expect to see impact until a lot further down the line and if there is no impact then you can ignore it and if anything at all improves then you can act as though it was your change that affected it. This is why people like Hattie are so important – so that we can have an evidence-informed discussion about how to actually improve our systems.
*Have schools in the UK improved? No. This is a really great paper where he discusses how politicians and other stakeholders have insisted that our schools are improving when in reality they aren’t. One of my favourite pieces ever. http://www.cem.org/attachments/publications/ImprovingEducation2013.pdf
Hattie is generally considered top dog when it comes to this kind of thing, but I’ve seen a couple of things recently which have made me question that. See here for a really intelligent critique http://evidencebasededucationalleadership.blogspot.co.uk/2017/01/the-school-research-lead-and-another.html
Hattie on academies, performance related pay and the politics of distraction https://www.pearson.com/hattie/distractions.html
It is worth noting that Hattie has his critics. See especially this brutal takedown of Visible Learning from a statistician who argues that VL is actually pseudoscience. Another piece critical by Gary Jones can be found here
Ashman’s piece on PISA https://gregashman.wordpress.com/2017/01/02/three-myths-about-pisa/
Sutton Trust’s toolkit – very heavily used but not without its critics https://educationendowmentfoundation.org.uk/evidence/teaching-learning-toolkit
Tom Bennett on Sir Ken Robinson and other junk policies: https://www.tes.com/news/blog/tom-bennett-reviews-%E2%80%98creative-schools-grassroots-revolution-thats-changing-education%E2%80%99-ken
Should systems set up to look at learning styles? No. http://www.montana.edu/facultyexcellence/documents/mar7_Pashlerarticle.pdf
Student/Teacher Led Education Policy
Newish section here which focuses more on the policy aspect. Nick Gibb hates student led or centred education: https://www.gov.uk/government/speeches/nick-gibb-the-evidence-in-favour-of-teacher-led-instruction
A recent piece by Anthony Radice points to the disaster that is French education here https://thetraditionalteacher.wordpress.com/2017/01/27/how-much-more-evidence-do-you-need/
Pupil premium and closing the gap
Lots of important statistics from Mary Bousted https://www.tes.com/news/school-news/breaking-views/teachers-their-own-cannot-compensate-endemic-childhood-poverty
See also below regarding Grit and Duckworth. Duckworth and others are classic magic bullet people. If only students had this one trait then everything would be fantastic… http://www.newyorker.com/culture/culture-desk/the-limits-of-grit.
There is another peer-reviewed piece here on the effect of grit and the tangle of other concepts it is tied up with.
A recent study shows that poor American students who start college after a basic “lay-theory” session where they are taught about not giving up and how the setbacks they face are normal and temporary have an increased chance of completing their course http://www.pnas.org/content/113/24/E3341
This post by the Learning Scientists highlights the need to be aware of educational disadvantage and the fact that student awareness of such disadvantage can reduce their performance http://www.learningscientists.org/blog/2017/1/5-1
This study from the states can be summarised as “spending money well can close the gap.”
Another study from the states here looking at the effect of socio-economic status on educational outcomes and whether the gap is closing
Student Welfare and mental health
School health and education survey: http://sheu.org.uk/content/page/young-people-2015
Mental health and exam stress is making it big in the news at the moment. Lots of people in the blogosphere have been writing about this (see here for summary https://teachingbattleground.wordpress.com/2016/07/17/the-child-mental-health-crisis-debate-part-2/) and the NHS has written about it and specifically how it is covered in the press here http://www.nhs.uk/news/2016/05May/Pages/Exam-stress-linked-to-teen-suicide.aspx
More data on how young people nowadays are smoking less drinking less etc. http://www.content.digital.nhs.uk/catalogue/PUB22610
Fascinating piece by cracked here about the pro-ana community.
Very interesting review of well-being here which shows that it actually had a positive effect. Some have questioned that it seems to be the same team finding the results in all of the studies.
Carol Dweck’s seminal work Mindset is a whole book but she summarises her key findings here: http://www.scientificamerican.com/article/the-secret-to-raising-smart-kids1/
One noted problem with the theory has been termed “false growth mindset” and has been acknowledged by Dweck and discussed here: http://www.learningspy.co.uk/psychology/why-the-false-growth-mindset-explains-so-much/
Robert Plomin is the leading advocate of a more genetics based approach due to his work on TEDS (Twins Early Development Study) and a discussion of his findings is here: https://www.tes.com/news/school-news/breaking-news/growth-mindset-theory-overplayed-and-could-be-harmful-geneticist
(Meanwhile some schools have clearly taken it too far https://www.google.co.uk/search?q=mindset+jedi&espv=2&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjK0Oy75obMAhUjQJoKHRtVC0MQ_AUIBygB&biw=1600&bih=775#imgrc=co0RvPqAd-DvUM%3A)
Recent publication on genes in education: http://www.nature.com/articles/nature17671.epdf?referrer_access_token=2E5cEQDiK9ji-H_y2Fk5ytRgN0jAjWel9jnR3ZoTv0NjGlOhelDS1V0LBMZZNHHhyuffIfhy5DYzI5gr8TBna0Du2PG-02HXDB6pphZISUYNMNBMGWuH4_-bE93V8jM4t2JW9KUwmxV1M8yfRRt5GSgbsrWSN4UP2_zdqC3wuDEUROXtLPnAYmtCzLYlGu7F-HbUOd3LwK_I86TruH7WReh2F3wtzRXoLTh4zzsPRTsP0pJvhmzS2mttovHgkvEv1BwaCxdZ132OaZ5IKYZ0Vw%3D%3D&tracking_referrer=www.theguardian.com
Fantastic and wide ranging review on cognition, genetics amd learning ability here
There is also Duckworth’s theory of Grit which is highly influential and Nicky Morgan is a big fan of. It’s also highly open to critique http://www.newstatesman.com/culture/books/2016/06/talent-trap-why-try-try-and-trying-again-isn-t-key-success
See also three star learning’s take on grit – full of references. https://3starlearningexperiences.wordpress.com/2016/07/05/to-grit-or-not-to-grit-thats-the-question/
*ED Hirsch and other “traditionalists” argue that the only way to actually close the gap is through the systematic accumulation of facts by the less well off https://atlantaclassical.org/wp-content/uploads/2014/08/Reading-Comprehension-E.D.-Hirsch-article.pdf
Jan 2017 following an article in Buzzfeed there has been a renewed focus on Growth Mindset. Andrew Old wrote a good summary here https://teachingbattleground.wordpress.com/2017/01/21/is-growth-mindset-the-new-brain-gym/
Another good piece here on the role of deliberate practice and nature in acquiring expertise (see also the Willingham review of Peak) https://3starlearningexperiences.wordpress.com/2017/01/24/expertise-a-good-old-naturenurture-debate/
There is a lot more to be said about Ericsson’s theory of deliberate practice. This article outlines the major issues and draws on papers like this (and Ericsson’s response). The seminal Macnamara paper is important too.
Very good summary of IQ for teachers here
Here is a collection of links building on the controversy surrounding The Bell Curve. There is also a suggestion here that there as well as the well-documented Flynn effect, there is also an anti-Flynn effect
There is a big debate online and in academic circles about all sorts of issues with IQ including the above. This article also argues that IQ and executive function are basically the same thing.
Every time someone mentions IQ on social media people seem to go nuts – it’s a very emotionally charged area. As well as the summary of IQ for teachers above this piece from Plomin is also a good primer
An overview of behaviour as it stands https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/379249/Below_20the_20radar_20-_20low-level_20disruption_20in_20the_20country_E2_80_99s_20classrooms.pdf
*Obviously as per Andrew Old good lesson planning isn’t the final thing – but it is a variable you can control. See other lies about behaviour here: https://teachingbattleground.wordpress.com/2006/10/30/the-top-five-lies-about-behaviour/ Andrew has a lot of pieces about the importance of a solid behaviour policy.
*Good stuff on behaviour is quite hard to come by. I imagine this is because research on behaviour is difficult. This is Tom Bennett’s recommendation to government for ITT on behaviour https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/536889/Behaviour_Management_report_final__11_July_2016.pdf. He is also here https://www.tes.com/news/tes-archive/tes-publication/how-we-solve-behaviour-crisis . Basically anything written by Bennett on behaviour is worth a read.
This digest from a working paper shows that being exposed to disruptive peers in schools can actually have a significant effect on future earnings – especially amongst disadvantaged students http://www.nber.org/digest/may16/w22042.html
This ridiculously interesting article about police interrogation techniques isn’t directly about teaching. However, we spend quite a bit of time trying to get to the bottom of the story. Perhaps as per the article a non-confrontational approach would be most effective? http://www.wired.com/2016/05/how-to-interrogate-suspects/
Joe Kirby teaches at Michaela where they have a very traditional behaviour approach with a very difficult demographic of students. He is always worth a read and has a lot of links too https://pragmaticreform.wordpress.com/2013/03/09/behaviour/. Michaela’s behaviour policy can be found here http://mcsbrent.co.uk/policies/
I’ve seen a couple of pieces recently looking at a behaviour system called “ready to learn” which strikes me as a really interesting, effective and streamlined policy. Read here for one digest https://thestableoyster.wordpress.com/2017/02/09/learning-and-thriving/
The most important thing about engagement is Coe’s simple maxim: engagement is not a proxy for learning.” Just because students are engaged doesnt mean they are actually learning anything.
*Hendrick quotes Nuthall (2007) and essentially argues that if students are engaged it’s probably because the work is too easy https://chronotopeblog.com/2015/03/22/engagement-just-because-theyre-busy-doesnt-mean-theyre-learning-anything/
For those who think that learning is the ends and motivation is the means then there is a further debate about which way round it goes. Are students “good” at a subject because they enjoy it or do they enjoy it because they are “good” at it? This experiment indicated the latter. Ashman’s summary is: “It found that the level of motivation in Grade 2 did not affect achievement in Grade 4. However it did find that the level of achievement in Grade 2 positively affected Motivation in Grade 4.” http://onlinelibrary.wiley.com/doi/10.1111/cdev.12458/full. This piece also has shedloads of further reading on motivation.
Some have also pointed out that PISA data actually shows an inverse trend – the more engaged students are the weaker their educational outcomes. However, even the author of this admits that it is not a necessary conclusion despite being worth thinking about. Unfortunately I can’t find this paper any more 😦
A major psychological theory is that of “self determination.” A summary can be found here as well as the Ryan and Deci (2000) article on the topic.
This academic piece investigates affect and problem solving and concludes that if students are not given enough guidance when solving problems they will have a negative affect towards them
Lots of research about how students cannot multi task http://journals.sagepub.com/doi/abs/10.1177/0956797616677314 and http://www.sciencedirect.com/science/article/pii/S0747563210000646
I don’t really know much about ed tech; it doesn’t particularly interest me.
The link for the “what makes great teaching” piece has a lot of information about teacher expertise and judging it accurately and reliably. See also here http://www.ippr.org/publications/beyond-the-plateau-the-case-for-an-institute-for-advanced-teaching for lots of stats on teacher impact.
*Deans for impact wrote a great piece with Anders Ericsson about how this should work for schools and teacher education, dwelling on the concept of deliberate practice https://doc-0c-9k-apps-viewer.googleusercontent.com/viewer/secure/pdf/cj8dpgh6oh84j3uf7tbn055drm1kl8m5/373it5mk5mmlrj6q0rv65i2a3d2jn3l7/1483690200000/gmail/03715936916408608607/ACFrOgAHwLCmJv2PZ-imL-C0Bu91FHVw9WLCpSIshsLNKLTc–QZuEgKhFL1ANm0MYEpcJ_3RI885JoecJgdIpXCEE1CadypZeJHRe2V5NWjwCj8r8hU-XtNygtOWw0=?print=true&nonce=78scsdjl99q3c&user=03715936916408608607&hash=aj04odib8om0eckahsgr8a4em2esr5nu
*Dan Willingham wrote a piece here where he reviews Ericsson’s Peak and wonders if it is even possible to apply deliberate practice in the field of teacher improvement. In it he also talks about the mindset and genetics thing. http://www.danielwillingham.com/daniel-willingham-science-and-education-blog/book-review-peak
*Really interesting article from Kris Boulton about the three major parts of teacher training: craft, pedagogical content knowledge and mindset (values). https://tothereal.wordpress.com/2016/09/17/teaching-teachers-a-silly-idea-researched-2016/
This article brings all the heat on graded lesson observations and has a lot of links to research. Big study here on lesson observations and potential racial bias in observers.
This piece involving Rob Coe discusses what makes effective CPDL.
This is still surprisingly a burgeoning field. We are riddled and plagued by snake oil salesmen. Gary’s blog is a great place to start on the scientific method and whether it applies to education http://garydavies.org/2016/12/29/academics-dont-even-read-education-research-teachers/
This piece by Kirschner and friends illustrates the intellectual weakness of the field https://3starlearningexperiences.wordpress.com/2017/01/10/will-the-educational-sciences-ever-grow-up/
They link to this really important piece about how professions become evidence based (or “mature”) and what we need to do in education to ditch dogma and embrace evidence http://www.wrightslaw.com/info/teach.profession.carnine.pdf
This piece by Ashman really could fit in multiple places here but it is about how you assess soft skills like grit and resilience. Contains a killer comment from Dylan Williams The fatal flaw in attempts to assess soft skills – http://wp.me/p3X3By-1fy
This is a cool guide for educators about the different types of evidential claims and how to assess them.
New section here sparked by Becky Allen’s marvellous piece here about reliability of inspections. David Didau wrote a good follow-up here. I definitely saw a graph depicting the unreliability of inspections on twitter somewhere as well as an article about how being a head at a school in a socially deprived area is career suicide but can’t find either or them.
Ofsted did an investigation into their reliability which came back with good results. They only looked at 22 inspections though and I reckon if an inspector knew they were part of a reliability investigation they would play it as safe as possible. Who knows. The always interesting Colin Richards wrote a response to it here.
New section here. This is a really broad and deep area and one in which I am conflicted about. Anthony Radice wrote a very challenging piece here which raises a lot of questions about provision.
Learning scientists have a good collection here as well.
New section following Ofsted’s renewed focus on curriculum.
HMCI Spielman’s speech is here
Sean Harford’s take can be found here
Schoolsweek wrote a very interesting discussion piece on this development here
Martin Robinson has long been pushing for a focus on curriculum and he wrote about Spielman’s speech here
I recently read Tim Oates’s piece on the new science curriculum here which is very interesting and well worth a read
Stuart Lock’s excellent long read on the topic is here