Wednesday, 9 July 2014


Dear Readers,

To publish some content I've been working on I've decided to migrate from Blogger over to my own domain

Whilst all pages on the blogspot page will redirect, at the moment they will only go to the homepage (I haven't yet worked out how to do it for each post).

Please update your RSS feeds and any links if you want them to go direct. And let me know if you run across any bugs. I'm new to the self-hosted wordpress thing so there might still be some issues I'm ironing out.



Sunday, 22 June 2014

How Many Lindy Hoppers are There

I've been wondering about this question for a while but with a little free time I finally got around to having a decent crack at working it out with some GIS and statistics.

The short answer: by my estimation about 120,000. Read on for the longer answer.

Where are people Lindy Hopping?

This is actually a somewhat difficult question. Scenes are constantly starting and folding - such as scenes in college towns in the US and those where expats are the primary drivers and consumers.* Plus the advent of the travelling lindy hopper has led to many camps being held in places that don't have a regular scene. For this purpose a "scene" is a location that actually has some form of regular Lindy hop be that classes, social dancing or some other organising activity.
Herrang only has dancing 5 weeks out of the year - that doesn't count. (photo by Rikomatic)
My starting point was the World Lindy Hop Map which I supplemented with maps for countries and smaller scenes including the LA Lindy Hop Map, The Lindy Hop Map Australia, Lindy Hop and Swing Dance in Italy, and the UK Lindy Map.

Next was quality control.

I ended up removing a whole bunch of points. There were plenty with incorrect geocoding (e.g. suburbs of cities that were coded to small towns, country entries sitting in the middle of nowhere etc.), I also did a fair bit of checking to ensure currency of schools, events, etc.** Finally I did a bunch of research to add new venues, website links and cover as broad a geography as possible.

The final result was 827 organisations, dance schools or other evidence of regular lindy hop activity in a particular location. I'm sure I've missed plenty of organisations in local areas - but my mission was to see if a location had lindy hop, not how many dance schools/societies were there.

Guess the map projection and you get a gold star.
As I don't plan on keeping this updated I'm not going to put it on google maps. However here is the data in kmz and shapefile format for those who wish to use the data in your own projects and maps. I've made my best effort with this data, but it's necessarily incomplete and the locations are rather approximate - don't use this for driving directions or holiday planning without further research!

How many Lindy Hop scenes are there?

Obviously, these locations aren't all individual scenes. Recognising that some scenes are supported by 1 large organisation and others by many smaller ones I wanted to get at the number of geographically independent scenes.

First I gathered venues to the nearest urban locality (using data from Geonames) - all those that were within about 15-20km I considered to be part of that locality. I merged a number of these together where the localities were separated by less than 30km - considering that this is probably the maximum distance (as the crow flies) for there to be enough mixing amongst venues for them to be

The answer - 463 scenes spread across 58 countries (or 59 depending on how you count Taiwan) and a range of self governing territories (e.g. New Caledonia, Hong Kong and the Åland Islands).

From this we can see that Lindy Hop is an activity for the relatively wealthy in the world - here is a chart of lindy hop prescene graphed against the Human Development Index***:

How many lindy hoppers are there?

Given the data I've generated here's a related question: How many people could lindy hop if they wanted to? To assess geographic access (leaving aside demographic and cultural factors that affect access) to the above listed venues I applied the World Population Layer to determine the number of people living within 15km of a lindy hop venue. The result: about 308 million people.

Now onto the number of lindy hoppers. Rather than try and guess the average scene size (which can be tricky) I've applied some fancier statistics and a Monte Carlo simulation to get a bounded guess. There's a more complete explanation and the code I used in a short R script I wrote here.

The assumptions I made are:
  • The size of lindy hop scenes are lognormally distributed. (Not bad - but without any data on actual scene sizes is untested)
  • The largest scene size is 5000. (This has been oft quoted in relation to the size of Seoul's lindy hop scene but London and LA/Orange County could also have sizes somewhere in this vicinity)
  • The median scene size is somewhere between 50 and 150.
  • The total number of scenes are 463.
The Monte Carlo simulation generated a stochastic set of 50,000 international lindy hop communities by randomly sampling the median scene size (from a uniform distribution) and then randomly sampling individual scene sizes (from the lognormal distribution) to get a total population of each. This then allowed statistics to be generated

This gives a median of 118,000 and a 90% chance of the "true" number being being between 82,000 and 153,000.****
Only 2% of lindy hoppers made it to Frankie 100. (Photo by hoptothebeat)

So now it's over to you. Can anyone else come up with a better answer?

* South Asia is a great example. I know of Lindy Hop being taught at one stage or another in Kathmandu, Mumbai, Dhaka, Chittagong, Bangalore, Dharamsala and Delhi at one time or another but combining short ex-pat contracts with a culture where partnered dancing is highly unusual it typically hasn't stuck around.

**It doesn't help that there are literally hundreds of dance schools and other organisations out there whose websites seem to have been created back when geocities was popular and left unchanged (except for content updates). Seriously people, if wordpress is too hard for you spend the money on a web designer.

*** And in those countries with Medium Human Development the lindy hop tends to be located in wealthier cities. This is probably also the case with lindy hop in countries with High and Very High Human Development.

**** The average and the mode were also about 118,000.

Saturday, 31 May 2014

The Twenty Most Watched Lindy Hop Videos

Next year will be the 10th anniversary of YouTube and lindy hop on the platform has certainly come a long way since this.* By my estimation lindy hop videos have been watched somewhere between 70 million and 200 million times on YouTube.** I thought I'd compile a list of the most watched swing dancing videos on YouTube.

I chose the top 20 videos by views (including aggregating the views from more than one copy of the film) that feature a reasonable amount of lindy hop or authentic jazz dance content (i.e. if it's "the swing", it ain't included). All these videos can be considered 'popular'*** to some extent given their large audience.

There'll be plenty on this list that's familiar - and maybe some that aren't:

1. Fast Swing Dancing - ULHS 2006 - 6.9 million views

The first video in YouTube search results for lindy hop comes from 2006 edition of the most influential lindy hop competitions in the contemporary scene. This is far from the only badass ULHS video on YouTube (ULHS also features two other videos in the top twenty) but it has been up there for 8 years and sure accumulated a lot of views over that time.

2. Denver Airport Holiday Flash Mob - 4.0 million views

This was the most viral lindy hop video of 2011. This was part of a big PR campaign by Denver Airport and the power of a marketing machine has helped push this into the number 2 spot.

3. Hooked On Swing Dancing - 2.7 million views

The music here is kind of square and the poster has basically cut together a whole series of classic B&W film clips of mostly white dancers (though it does finish with highlights from Hellzapoppin').

4. Whiteys Lindy Hoppers .. Hellzapoppin - 2.6 million views

The greatest lindy hop routine on film performed by Whitey's Lindy Hoppers and choreographed by Frankie Manning. This clip has inspired recreations and competitions and it remains the most referenced and loved clip of contemporary lindy hoppers.

5. Charleston -- Original Al & Leon Style!! - 1.9 million views 

Demonstration of classic Charleston steps by Al Minns and Leon James at the Savoy Ballroom. This was filmed by Mura Dehn as part of her legendary Spirit Moves documentary. Only small excerpts of this exist online - the full documentary is almost six hours long and only viewable at a small number of institutions. This video's popularity probably has something to do with the numerous remix videos (typically with modern electronica overdubbed) that have been made - note that I haven't included these in the view count.

6. Swing Dancing from the Movie Twiced Blessed (1945) - 1.8 million views

This film features some of the best swing dancers from Southern California during the 40s many of whom continued to dance and teach Balboa and Lindy Hop during the revival. The dancers are Hal Takier & Alice Scott, Lenny & Kay Smith, Wally & Mousie Albright, Freda Angela Wyckoff, Bob Ashley, Chuck Saggau.

7. Lindy Hop funny instructional video : Groovie Movie (1944) - 1.6 million views

This short film shot in 1942 again features great Southern California swing dancers (including many of those in the clip in the number 6 position). It's well known for its comical style and spoof of dance instruction techniques.

8. Lindy Hop Dance – Charleston meets Lindy Hop - 1.5 million views

From the 2007 Jump Session Show (put on as part of Camp Jitterbug, it is the best annual revue of authentic jazz dance) Annie Trudeau and Max Pitruzzella perform a fantastic routine of Charleston and Lindy Hop.

9. 1920s Charleston - 1.2 million views

The wonderful Sharon Davis compiled this video of vintage clips of people dancing Charleston. Though it's been online since 2009 I'd guess that it's views have shot up recently thanks to the Gatsby effect.

10. Shim Sham - 1.2 million views

Frankie Manning demonstrates the Shim Sham with Erin Stevens. This is by far the most watched Shim Sham video on YouTube, though there are many, many other videos out there.

11. Swing Dancing to Bill Haley and the Comets (1956) - 1.2 million views

Although this one is definitely getting into boogie and rock and roll there's still enough recognisable Lindy content that makes this the only 50s film to make the top twenty.

12. Caravan Palace - Dramophone [OFFICIAL VIDEO] - 1.1 million views

I debated about including this one as it is electro-swing music. However Caravan Palace does work quite a lot with Lindy Hoppers and there's some of the best featured in this music video. With the popularity of electro-swing in Europe it's odd that this video doesn't have many more views.

13. Gap Commercial - Khaki Swing - 1.0 million views

Air Steps, bullet time and neo-swing - the pinnacle of the 90s revival. Gap made a whole series of commercials featuring its khakis in the late 90s (including Soul, Go-Go, Country, Rock and Hip Hop) but this one has seen more YouTube views since its 2006 upload than the rest of them combined.

14. Slow Club - Two Cousins - 1.0 million views

Reminiscent of the Spirit Moves this 2011 music video features Ryan François and Remy Kouakou Kouame. It was one of the most popular videos for 2011 and remains in the top 20.

15. Tricks & Airsteps for Swing - Dance Clip - 800,000 views

Though this is just a promo video for an instructional DVD on aerials it features 5 minutes of various air steps. Nearly all of the videos in this list feature some sort of air time so that might be why this film has so many views.

16. ULHS 2006 Charleston Finals Dance-Off  - 800,000 views

ULHS represents again with the 2006 (the same year as the Liberation finals which hold the number 1 spot) finals of the Charleston competition.

17. ILHC 2013 - Invitational Strictly Lindy Hop Finals - 700,000 views

This film got picked up on 9GAG and has since accumulated many views. I didn't realise this one had gone viral that way until Mikey mentioned it during the Frankie 100 livestream.

18. ILHC 2011 - Champions Strictly Lindy - Finals - Spotlights - 700,000 views

ILHC again, this time coming in with slightly fewer views in a much longer time span.

19. The Basics of Lindy Hop - 700,000 views

I'm surprised an instructional video has made it's way into the top 20 (and one with pretty poor production values - which the maker does admit!) but here it is.

20. ULHS 2005 - awsome!!! charleston-finals - 700,000 views

Rounding out the list is yet more bad-assery from ULHS and the fourth Charleston video in the top 20. Just goes to show that the world thinks solo dancing is pretty awesome too.

* YouTube doesn't make it terribly easy to search for old videos. This was the first one that I could find that hasn't subsequently been deleted. Yehoodi's 7th Anniversary Red Carpet celebrations was a close second.

** I worked this out by gathering data on youtube views of "Lindy Hop" videos of the top 10 search results and then the 20*k th search result (for k=1:25) fitting a power law function (R^2=0.99) and integrating this function between 1 and 200,000 (approximately the number of search results). The 70 million is the mean number whilst the upper bound was based on the standard errors. I figure that the loss of videos without "lindy hop" in the title or description will be made up for by the false inclusion of "the swing" videos.

*** As I noted above the distribution of views of lindy hop videos appears to follow a power law (at least for videos with more than 10,000 views) so there doesn't appear to be be any sort of threshold, above which one can call the video popular. I also use the term popular here rather than viral, which typically denotes a rapid accumulation of views.

Thursday, 6 February 2014

Who's on first? Performance order and judging bias in Lindy Hop contests

Making decisions is hard. Judging in contests is a hard form of decision making - there's so much to consider. What's worse is that your own brain will try and prevent you from making the best decision. For example every time someone has to decide on information being presented to them, the order of the presentation of that information can change their decision.

A variety of studies have found this 'performance order' bias in everything from the Idol series, Eurovision and figure skating and music competitions. This bias isn't inconsequential either, in events where careers can rest on the outcome performance order bias can have a significant impacts.

So what about Lindy Hop competitions? Does the order of appearance matter?
Judging - an unenviable task (photo by Jerry Almonte)
In the spirit of my previous post on electoral methods I've delved into the data so you don't have to. My source: results from the 2013 and 2011 European Swing Dance Championships (most of the other major contests I've looked at don't provide the performance order with the official results - if anyone has the data and wants to send it to me to include in the analysis I'd be happy to expand it). This provides a dataset of 30 contests with between 4 and 15 individuals, couples or groups in each contest.

For analysis I've converted all the placings into standardised scores to enable comparison between contests of varying lengths.

Here's what the data looks like:
You can see that the number of competitors in gets rather smaller for the larger events, but you can visually see a slight rising trend even when you discount the results in larger divisions.

To test whether this was just a statistical quirk I set up a multi-linear regression model with an order variable and two additional variables to see if there were any effect of appearing first or last in addition to to the performance order effect.

Here's the model statistics:

Estimate Standard Error T Statistic Pr(>|t|)
(Intercept) -0.35908 0.15729 -2.283 0.0234
First 0.29989 0.22564 1.329 0.1852
Last 0.08663 0.21062 0.411 0.6813
Order 0.06666 0.02848 2.34 0.0202
This table is only for statistics nerds - otherwise you can ignore it.

These data show that there appears to be a small performance order bias in these results - but though it's at the level of significance that could get you published in certain social science journals I'd be hesitant to say that it exists for sure.

On the other hand, beyond the performance order bias there appears to be nothing special about appearing first or last.

Converting out of standardised scores let's look at what these results could mean in an actual contest or let's say 12 people. If the differences between everyone's score is similar (which is not really realistic, unless there's a tight contest) - this effect could mean the difference two places if you appeared first instead of last.
From xkcd - full comic here
What could be going on here? Firstly it could very well be nothing. The order bias is only just within the normal 95% p value - which is not nearly as impressive as you might think. More data could cause the effect to disappear.

EDIT: But, not so fast, remember how there were only a handful of divisions with large numbers in them? There was only a single division with 15 competitors and only a single one with 12. What happens if we repeat the analysis with them removed? (and thanks to one of my FB friends for suggesting this analysis) Here's the results:

Max size Estimate Standard Error T Statistic Pr(>|t|)
15 0.06666 0.02848 2.34 0.0202
12 0.085237 0.034704 2.456 0.0149
11 0.07006 0.03885 1.803 0.0729
10 0.06518 0.05556 1.173 0.243
9 0.08808 0.06351 1.387 0.168
8 0.06139 0.07081 0.867 0.388
6 0.005641 0.124636 0.045 0.964
5 0.333 0.2568 1.297 0.202
 Again - tune out of this table if you're not a statistics nerd

Remove the two largest divisions and the order bias effect quickly disappears. So we can be reasonably confident that there is no performance order bias for competitions smaller than 10 or so entrants. For larger divisions we've really only got two contests to go off - this is really not enough data to be able to say one way or the other.
It's reasonable that if judges are affected by a recency bias then this may only appear in larger contests. But there are also other explanations besides a recency bias on the part of the judges. Audience reaction could change throughout an individual contest and this could subtly bias the evaluations of the judges.

So how could we find out if there is an order bias? More data on the largest divisions could help but the ultimate would be a controlled experiment. Judges would watch performances on video and in different orders for each group of judges. You could also implement this in actual competitions which would effectively control for any performance order bias present, but such a radical change to judging practices is unlikely to catch on.

If you're a competition organiser and you don't randomise the performance order of your competitors, you really should. If an order bias does exist then it's easily something that could build up over time and give some people (for example with names at the end of the alphabet) an edge in landing that all elusive international teaching gig. Releasing judge scores may also help - some research suggests that increased transparency, the idea of someone looking over your shoulder, can help reduce unconscious biases.

Sadly the major international lindy competitions aren't consistent in this practice, both ILHC and ESDC have posted individual judges scores previously but not for every year (and the ILHC results do not contain performance order - and appear to have been taken down), the National Jitterbug Championships, the US Open, the American Lindy Hop Championships, the Canadian Swing Dance Championships, The Snowball and Lindy Shock do not.
I'm not talking about that sort of bias
There are potentially a range of other biases that could be relevant to Lindy Hop competitions such as reference bias (where a judge gives a higher score to a person they are familiar with - though it's unlikely to occur at the highest levels where the competitors are all familiar to the judges), difficulty bias (where more difficult routines are scored higher, even if difficulty is scored separately), in-group bias (a close relative of reference bias - where a person is judged more favourably because they share the same dance school/city/country/race etc. with the judge), the halo effect (where one element of a persons character, such as attractiveness, influences assessments of other elements of their character), memory-influenced bias (where past performance influences current assessments) and groupthink (where a group of judges reaches a false consensus - this isn't a problem when each judge scores independently, which appears to be the practice for most international comps).

Finally I want to emphasise that I'm not suggesting that judges are behaving unprofessionally. The problem with cognitive biases is that we all have them, they can't be switched off and thus require a lot of cognitive energy to overcome. Awareness and acknowledgement of potential bias can go a fair way to moderating their influence.

For further reading check out this article "Natural Bias, the Hidden Controversy in Judging Sports" or if you're interested in cognitive biases and the psychology of decision making grab a copy of Daniel Kahneman's "Thinking Fast and Slow".

If you've read this far congratulations! Have a picture of an echidna:

Thursday, 16 January 2014

5 Ways to put the Äwesome in Your Herräng

So registrations are open and it's crunch time (for HDC's servers at least - depending on what you want to go there to do there's still time to make a decision for yourself). In my last post I set out some of the reasons why you might want to reconsider going. I'm not going to rebut myself here (let's be honest, pretty much everyone else will tell you why you should go to Herräng) - I'm really more interested in how your time in Herräng can go off like a frog in a sock.

Image by Warky
So here's a few ideas both on and off the beaten path that might make your Herräng more Awesome.

1 - Research and Planning 
Ralf Brown: Herrang 2010 &emdash; Kuggen grocery store
There is no ATM (and occasionally other essentials) at the Kuggen (photo by Ralf Brown)
Do your homework. As Herräng is stuck out in (almost) the middle of nowhere being unprepared for your time there can really cramp your enjoyment. A good place to start is my list of Herräng resources. Also make sure you check out the Friday Night Parties for costume ideas. A great resource are friends and people in your scene who have been recently, there's also the forums and the facebook group.

Even if you've been before don't assume that important things. Things get changed every year, particularly with things like registration, camp facilities, safety and security. Make sure you have a good look through the materials on the website, read the booklet you get on arrival and attend the first Saturday night meeting.

Armed with your research, it's time to start planning. Friday party costumes is the big one that everyone works on prior, but if you've got an idea for something cool (like break-away stripper pants) you may need to bring materials (like velcro) or even start scheming with fellow collaborators (if you want a full all-male revue).

2 - Volunteer
The 2013 Crashdown crew (photo by Herrang)
There are many people who keep going back to Herräng and volunteering. I did three weeks last year and can't recommend it highly enough. It's a great way to meet people, learn how the camp works and find out some of the inside information on what's happening around camp (like secret blues parties). If you're the kind of person who likes to get involved and give back, it can be incredibly rewarding. It can also make your time at Herräng much more affordable.

In addition to HDC volunteering you can volunteer for a week in Heaven's Kitchen/Bar Bedlam/Blue Moon Cafe, help out with Mission Impossible (rumour has it that the floating dancefloor will make its long awaited début this year) or the decorations and planning for the Friday Night parties, other random happenings in camp or just generally helping out when there's opportunity.

3 - Take Private Lessons
Finding somewhere to do your private lesson could also prove challenging (photo by Lloyd)
Herräng has one of the largest concentrations of the best lindy hoppers and the best lindy hop teachers of any event in the world. But whilst they might be there, that doesn't mean they're teaching you. You might be in a different class track, unable to be there the full week or just not have those teachers in your stream. If the lindyverse doesn't align in your favour, take matters into your own hands and arrange a private lesson with your favourite teacher(s).

Besides, if you really want to supercharge your lindy hop, then private lessons are a great way to help make that happen.

Private lessons are something you arrange yourself with the teachers - and fair warning they might say no. But hey, you got nothing to lose by asking.

4 - Bring your creative side
People making art of people making music - illustration by Jimbino Vegan
Do you play a musical instrument, dance (something other than Lindy hop), act, paint, do puppetry, sketch, stand up comedy, make films, write, or any one of zillions of other creative pursuits? Then you're in good company. Herräng is replete with tonnes of creative individuals having jam sessions, making movies, doing photoshoots, painting, circus and more.

Collaborate with like-minded creative people, who knows where it might take you. If you need tools, instruments or materials for your craft then make sure you bring them along.

5 - Do something awesome

Ask someone who has been in the last couple of years about the goats (photo by Niko Huttunen)
Herräng seems to be more famous for all the shenanigans that go on there than the dancing. From All of the "This one time at Herräng" and "Only in Herräng" stories need people to make them happen. Sure a lot of the crazy is done by staff, volunteers or in association with the Friday Night parties, but that shouldn't stop you. In fact one of the complaints I heard from a few old-hands at the camp is that regular campers aren't bringing the shenanigans like they used to.

So make something awesome happen - it could be as simple as fixing random posters around the camp;
We never figured out who was doing these (photo by Lloyd)
Borrowing a costume from the prop shop and wearing it for pretty much the entire camp; or something more complicated, requiring a group of people and some planning; like random performances from an 'all-male revue'.

But you should figure something out for yourself. Herräng is a place where you can make ideas happen - enlist the help of some other campers, ask if you can borrow tools and materials from the No-No Box, or even get Mission Impossible involved. If you're idea's good enough you might even be able to get an announcement in the camp newsletter or the evening meeting. And I wouldn't be too concerned about doing something that's already been done - even if it has, only a small number of folk there will have experienced it.

Jazz and Lindy Hop are all about improvisation, well so is Herräng. So do whatcha wanna and have an awesome time.