Au revoir

I finished my data acquisition! I downloaded my database last night, checked, and found out. Three more folks completed the instruction in the experimental group that had been lagging behind. They put me over the top. (Thanks!) That was a long year and a half. I can't believe I have the data!

I met with my advisor today and we worked on a plan to finish the dissertation. I'm shooting for May graduation, so I have to get analyzing and writing. As such, there will be no more Juggling is a Snap! - The Blog for a while. Signing off for now.

BTW - Juggling is a Snap! is still functional. I'll even be collecting data for a while, until I make my final analysis. I might as well continue to pick up data until the last minute, my findings will be more robust as a result.

The Science of Juggling

Are you curious about juggling? Are you eager to read an entertaining and fascinating scholarly paper on the topic? Here's your site:

The Science of Juggling

It is simply the coolest article.

It is written by two giants in the field, Arthur Lewbel and Peter J. Beek. Lewbel is an accomplished juggler and perhaps the most recognized, respected, and published scholar in the field of juggling. Here's the kicker, Professor Lewbel is also the 20th most-published Economist in the world! Beek is a movement scientist at the Faculty of Human Movement at the Free University in Amsterdam. He and his colleagues churn out volumes of scientific research that frequently use juggling as a guinea pig. They were extremely kind and helpful to me. I was thrilled when one of the team, Joost Dessing (I love those Dutch names!), sent me a small library of their publications to help me with my research. These books were the theoretical underpinning to the method of instruction at Juggling is a Snap!

The article discusses various topics. After a brief history of juggling, it gets right into some of the scientific research focusing on juggling. You have no idea. Lots of people have looked at this activity in many ways, and some of the research is jaw-dropping. (I suppose this depends on the reader.)

A fitting start is a summary of Claude Shannon's work in juggling. He is the author of the Juggling Theorem. I discussed it briefly a few weeks ago in ...Time for Math. Like Lewbel is, Shannon was a prominent academic figure outside of the field of juggling. In his case, the field was information theory, and he was consider this field's father. Given our current and ever-increasing fascination with and love of computers, I'm surprised that his name is not more widely known. Bill Gates is much more famous, but he "merely" monetized Shannon's visions.

One of my favorites is the research on the gaze of jugglers. A juggler can't look at his hands. The information needed to catch objects is completely contained at the top of the flight path. Here the objects travel most slowly and, when sighted and tracked, our brains can extrapolate speeds and angles of objects to predict where they'll be when it's time to catch them. As such, jugglers stare somewhat blankly at an oval region high in the juggling pattern. One finding is that elite jugglers gaze at a much smaller, tighter field than do beginners. The really cool thing about this research is the instrumentation, though. It ranges from liquid crystal glasses to sensors detecting contractions in eye muscles!

The remainder of the article covers two more topics, juggling robots and siteswaps. Humans are no longer the only juggling machines. With the advent of fast computers, optical recognition, and robotics, engineers now have devised robots that can juggle! I imagine that practical applications are limited, but the rigor in achieving this goal has produced many understandings and insights. Finally, there is a great summary regarding siteswap notation. Nearly every juggling pattern can be expressed as a series of numbers. The system for this is called siteswap notation. Many jugglers use siteswap to explore new juggling vistas. They try to do every pattern. Instead of painting by numbers, they juggle by numbers.

Go there now (The Science of Juggling) and read it. Then, if you don't know how already, learn how yourself at Juggling is a Snap!

When you say "juggled," you mean "dropped."

Ah, football season! I love this time of year. Despite the crappy weather and increasing gloom and darkness, you can find a game on TV at almost any time of day or night. My Eagles are struggling mightily, but even that doesn't keep me away. There are so many ways to enjoy. I can drop by a friend's house and help him scream at his television. I can choose to have refreshments. Food and drink are critical. Maybe some wings and a beer or three. Sour cream and onion chips are nice. If you really want to go all out, you can take out an additional mortgage and pick up some season tickets. Then you can tailgate in "The Link" parking lot at every home game , which closely resembles scenes from that 80's Mel Gibson movie, Mad Max.

I even look forward to the press. I like great sportswriting and great sports reporting on TV. Who doesn't like the playful, self-deprecating, and topical stories told by Rick Reilly? Who doesn't appreciate the frank, funny, and spontaneous color of John Madden? How about Chris Berman calling a long fumble return by an interior lineman, "Rumblin', Bumblin', Stumblin'?" Frank DeFord spans both worlds, writing for years for Sport Illustrated, and now broadcasting regularly on NPR. Yes, I like great sports journalism, but, unfortunately, even the best reporters are not entirely attentive to our language.

I have a variety of pet peeves, but none is more of a pet, and none gets me more peeved, than when a announcer or writer incorrectly refers to a dropped ball as a juggled ball. Here are two examples:

Boston Herald
Ryan, BC keep adding to accomplishments
Sunday, November 25, 2007
BC was driving late in the half when Ryan dumped a short pass to Rich Gunnell, who JUGGLED THE BALL before Miami defensive back Kenny Phillips swooped in to pick it off at the Miami 9-yard line with 52 seconds left.

http://www.49ers.com
49ers/Denver Qtr Summaries
August 13, 2007
Dilfer found Gilmore for a first down catch that officials initially ruled as being incomplete, saying that Gilmore JUGGLED THE PASS.

Think about it. What does a juggler do? Anyone can drop a ball, but a juggler actually catches balls. Gunnell and Gilmore didn't juggle their respective catches. If they had juggled their catches, Kenny Phillips would have one less interception, and Trent Dilfer would have had one more first down. The problem is that Gunnell and Gilmore failed to juggle their passes.

Here's where this kind of usage is not only annoying but also confusing in our current Juggling is a Snap! context:

Posted by: Curmudgeon | January 12, 2007 08:45 PM
Dallas, whose Tony Romo, Boy Wonder, juggled the snap on a ''gimme" field goal that would have...

(As an Eagle fan, I had a lot of fun with that particular play) He didn't juggle the snap. If he had, Dallas would have won.

Oh well, maybe this blog will help forward the cause of correct usage vis a vis juggling. I love to hear things like:

http://sports.yahoo.com/nfl
Baltimore Ravens wide receiver Derrick Mason, left, makes a juggling catch for 19-yard reception in front of San Diego Chargers Eric Weddle, right, during the first quarter of an NFL football game Sunday, Nov. 25, 2007 in San Diego.

Now that's accurate reporting!

Whether you're an NFL receiver, a fishmonger in Seattle, or a juggling wannabee, cruise over to Juggling is a Snap! It is free and gradual. You'll probably get better at juggling (not dropping). Good luck and have fun.

Juggling is a Snap!, but a dissertation is just about the farthest thing from being a Snap!

As a male I'll never know for sure how childbirth feels. I suspect though, that even though the dissertation process has far less physical discomfort, it's prodigious mental anguish and seemingly endless seven years is beginning to give me some small amount of insight regarding the nature of real pain. Prenatal care is analogous to coursework. The timing of this stage is aligned with that mainstay of early gestation, morning sickness, which correlates with the swirling, nauseating helplessness felt by doctoral students when trying to figure out a topic of study. Pregnant moms and students both wander aimlessly as they get used to this new-found situation and, even in the best of cases, wonder occasionally, "Why did I get myself into this mess?"

The second trimester tends to be a somewhat blissful, glowing period for the expectant mother. She's passed the vomiting stage and hasn't yet begun to dilate. The pre-PhD's have a similar phase, when they have committed to a project and are busily, eagerly engrossed in their work. They, like the expectant moms at this point, feel the rush of doing something miraculous but have yet to experience the fatigue of a long and somewhat tedious and boring slog (This extended ranting whine exemplifies the real genesis for this portmanteau. Some erudite but misguided soul thought the term came from combining "Web" with "Log"). I have fond memories of those halcyon periods of focused and productive, albeit naive, time. Oh, those were the days.

Fast forward to the final pushing and the birth itself. Here is a mother's painful but exhilarating evolutionary reason for being. I imagine with fear and trepidation that my dissertation defense will resemble this experience. In the months leading up to "birth" (The light at the end of my personal tunnel - hold on here, I intended this to be a birthing allusion!) I'll experience the feeling of carrying around a huge weight. My normal life activities will be somewhat limited and may be curtailed completely in the event of "complications," like faulty data or a recalcitrant review board member. In my discussions with women at the analogous stage, I've found that, while their primary concern is the health of their child, many of them just want it to be over, at nearly any cost. This sentiment I understand completely and share with my pregnant sisters.

Unfortunately for women giving birth, their pain is typically intense. I think it was Bill Cosby who said that if you want to know how childbirth feels, imagine pulling your lower lip over your face to the top of your head (The laugh track, which undoubtedly included mothers, went off after this comic "delivery," but how exactly did Dr. Huxtable know this? Gratefully, I never will.) Fortunately for most mothers, it "only" lasts for a matter of hours. We ABD's (students who are "All But Dissertation") don't have the relative luxury of this more brief form of torture. If you extend the anguish past hours to days, weeks and months, you've arrived at our current affliction: chronic academic labor. Waterboarding is looking good.

Nothing can truly compare to the birth of a child. There is relief, great quantities of the most wonderful concoction of hormones, and a flood of love. I won't get the hormones or love, but I will have a big stack of paper and those three letters after my name, and I desperately look forward to the relief that will come with graduation.

P.S. - There's a special place in heaven for those intrepid masters of pain and achievement - Ph.D. moms.

P.P.S. - You may decide to take on either of these monumentally daunting but incomparably rewarding travails. If it's the reproduction thing, do it with someone (in my case, my wonderful wife) you love. If it's the Ph.D. thing, do it with something (in my case, juggling) you love. It helps in getting through the rough patches.

Is juggling an open or closed skill? (BTW - What's the difference?)

The notion of closed skills versus open skills is a useful construct in the sport sciences. By categorizing different sports, and different skills within sports, as either closed or open, the reporter, athlete, fan, or coach can better analyze, diagnose, appreciate, and make recommendations to improve athletic performance. Juggling is an activity that is readily and constructively categorized this way. What's the difference between the two?

From my dissertation draft:

Individual juggling is a closed skill. A closed athletic skill is defined as one which has no interdependence on the activity of another person. For example, the high jump is a closed skill. The high jumper’s task is to clear the bar. She can do so at her own pace, without worry of interference from an opponent. Nor does she depend on a teammate for assistance.

An open athletic skill must account for another person’s help or hindrance. Playing tennis, for example, is an open skill. Every shot by a tennis player is dependent upon the position, movement, ability, and mental state of the opponent. Decisions must be made in real time. Adjustments must be made constantly to variations beyond the control of the player. Indeed, one strategy in sports using open skills is to make these adjustments as unpredictable and widely varying as possible, to throw off the competing athlete. Tennis can also be described as an open skill for its dependency on teamwork. In doubles tennis, it is critical to know the position, movement, ability, and mental state of one’s teammate as well as those of the opponent. It has been argued by singles tennis purists that singles tennis is much more demanding than doubles. This may be true in the physical sense, but there is much more activity to track in doubles than in singles!

Juggling is most frequently performed on an individual basis. In this mode, and for the purposes of this study, juggling is a closed skill. Learning and performing the skills of juggling can be done at the pace of the performer. Like the high jump mentioned above, the variables associated with performing the task can be controlled by only one person, the juggler himself.

One variant of juggling, passing, requires open skills. When jugglers collaborate to pass clubs among themselves, they must account for variability introduced by others. Like the tennis players mentioned above, they must decide in real time how to adjust for errant throws, varying body positions, and skill levels of their collaborators. It is hard to imagine a juggler not learning the closed skill of juggling first, before advancing to the open skill of passing.

Like many pursuits, juggling can serve as a metaphor for life. In order to succeed, you need determination and persistence more that anything else. Talent helps. A good teacher and good instruction help, but note the wise adage, “When the student is ready, the teacher will appear." After these attitudes are internalized, Juggling (truly) is a Snap!, and the juggler can move on effectively to passing. This transition from the solitary to the social also has an analog in human relationships. It is akin to "get your stuff together" (60's lingo), "be the change" (Ghandi lingo), and, "If emergency oxygen masks deploy, put on your own mask first, then your child's" (airline safety lingo). You can only help others after you've taken care of and developed yourself. Similarly, you can only pass with other jugglers after your own patterns are solid.

Something to wrap your head around. Time for math.

I hope everyone had a great Thanksgiving yesterday. Now that you're recovering from your tryptophan coma, let's get back to juggling, shall we?

Claude Shannon was not only "The father of information technology." He was a juggler, too. What a stroke of luck that was. Mr. Shannon was able to capture the essence of juggling in a simple and elegant math equation. From my dissertation draft:

Shannon’s Equation, or the common equation of juggling:

(t_u + t_l)/H = (t_f + t_l)/N

where: t_u = the time that hands are unloaded

t_l = the time that hands are loaded

t_f = the time that the bean-bags are in flight

H = the number of hands

N = the number of bean-bags

Verbally, this equates the two perspectives of juggling: bean-bags and hands. In the cascade, the bean-bags “experience” being in two alternating states: free flight (t_f) and in a hand (t_l). The hands also “experience” being in two alternating states: unloaded (t_u) and loaded (t_l). Therefore, for any given period of time while juggling is occurring:
(The total time experienced by all hands)/H = (The total time experienced by all bean-bags)/N

Get it? If not, here is the subject blown out.

So, what does this tell us?

One interesting number in that mess above is t_l = the time that hands are loaded. This is also referred to as dwell time, or the time that it takes the hand to catch and throw any given ball. A common inference of novice jugglers or non-jugglers is, "Why don't you just throw 'em higher? Then you'd have plenty of time to juggle about a dozen of 'em." Well, that does sound easy. The problem is dwell time. In order to "throw 'em higher," the juggler needs to wind up, pulling the hand down and applying a strong force to the ball (or bean bag). This increases dwell time. When you add balls, you decrease time available for your hands to take care of them all. If you pile up all of those dwell times, the elite juggler's hands are a blur.

The other factor that comes into play is accuracy. Every throw has some error associated with it. It is thrown at the wrong speed and angle. The harder and higher the throw, the more pronounced are the effects of the errors in throwing. As such, the best jugglers in the world can't keep more than nine balls going for an extended period of time. The best ever achieved so far is eleven, and that was "only" a flash, or a pattern where each ball is thrown once and caught by the correct hand in the correct order. (Detail - actually, the best so far is fourteen throws and catches with eleven balls - a flash plus three.)

Why bean bags?

Last week (November 18th - Juggling is a Snap! - The Blog) I discussed the problems with juggling scarves. Beautiful yes, but juggling scarves gets one no closer to juggling per se. This observation was based on Huatala's (1985) research. The skills needed for juggling scarves are not necessarily helpful in learning to juggle balls or bean bags. If your aim is to juggle the three ball cascade as soon as possible, skip the scarves.

Huatala was a busy juggling researcher in the eighties. From the draft of my dissertation:

Huatala’s second major finding (1988) is that bean bags are superior to balls for learners. In his testing, the results kept coming up better for bean bags. Why did this happen? He didn’t get the answer until after he did qualitative interviews with his participants. As is turns out, the major factor in the superiority of bean bags was not their texture, weight, or their ease of catching or throwing. The most important factor by far is that they don’t bounce! As a result, during the trial and error of learning, the students spend less of their time retrieving missed balls and more of their time on task juggling bean bags. Over the sometimes significant time working to learn, this seemingly minor difference adds up to a great savings in time and energy that can reduce anxiety and frustration and promote learning.

In short, you only have so much time to learn before frustration sets in. Why waste this precious time chasing balls all over the place? Use bean bags.

Bean bags are relatively inexpensive, not dangerous, and can be found everywhere. Big hacky sacks are perfect and are found at sporting goods stores. You can even make juggling bean bags. Many kinds of fruit are excellent for juggling - oranges, apples, and coconuts come to mind. Apples have the significant and distinct advantage of being edible. Eating an apple during a performance is a winner every time, with laughs correlated directly to the amount of mess created, and inversely to the age of the audience. The problem with fruit is that it gets mushy after you drop it a few times, or painful if it lands on your head in the case of a coconut. Stick with bean bags.

Reference:

Huatala, R. M. (1988). Does transfer of training help children learn juggling? Perceptual and Motor Skills, 67, 563 - 567.