Classroom game: 'Cher Says

So here's the story. For the 2-day Freshman Orientation event a few weeks ago, I was asked to give an administration briefing to a lecture theatre of about 400 eager freshmen in the morning of the first day. The purpose of the briefing was mainly to inform the freshies about the agenda for the next two days. However, there was a concern that the programme that morning might be too short, so I casually mentioned that "at worst, I could run a game."

Next thing I knew, the official programme schedule says Administrative Briefing & Games, and I was committed to running a game for 400 people. Jaw. Drop.

The red ellipse represented the bloodbath that would occur if the game fell flat.

There aren't many games that can accommodate 400 people, and even fewer in a restricted environment like a lecture theatre. The students will be seated in rows with classmates that they have just met, clutching their goodie bags and wondering what exciting thing is going to happen next. I needed a game that could keep everyone involved (or at least interested) for maybe 10 minutes, which doesn't sound like much until you realize that we're dealing with a bunch of impatient, worldly and cynical 17-year-olds.

There was really only one choice. I was going to have to try a version of Simon Says.

'Nuff said.
(source: http://backseatcuddler.com/wp-content/uploads/2008/05/simoncowell.jpg)

If you've gone through kindergarten or been to one of those kiddie birthday parties with balloons and clowns, then chances are you know the rules of Simon Says. On the off chance that you've had a deprived childhood, the rules are as follows. One person plays the role of Simon, and he gives a series of instructions. If he gives an instruction preceded by "Simon says," then the players must follow the instruction without hesitation (e.g., "Simon Says, raise your right hand."). If the instruction is not preceded by "Simon says,", then the players must do nothing and maintain the previous position (e.g., "Raise your left hand."). Anyone not following these rules is out, and the last one remaining wins the game.

Sounds like a boring kids' game, right? Well, educators have recommended Simon Says as a good game to teach children how to follow instructions, improve their concentration, practice logical thinking and motor skills...oh, who am I kidding? I want to run Simon Says because it gives me the chance to be a troll (or, more accurately, it gives me a chance to trololol).

The success of a game of Simon Says depends completely on the instructions given by Simon. If the instructions are boring, the players get bored. If they are unfair, the players get resentful. The key is to design the instructions with misdirection in mind so that as the players drop out, they realize their error and are impressed by the deviousness of the instructions. Hopefully, they will continue to pay attention to the rest of the game in order to figure out what trollish trick I was going to play next.

The game I played is identical to Simon Says, except that I called it 'Cher Says because, well, my name is not Simon (it's 'Cher). Also, I stated that the game is active only when the Scumbag Steve cap is on the screen. After I explained the instructions, I started the game. 

Hat on screen - Game On!
(source: http://i0.kym-cdn.com/photos/images/masonry/000/160/673/ScumbagSteveHat.png?1313097115)

Here is a partial transcript of the instructions I gave. As an exercise, try to read each instruction one at a time and imagine how you would react.

1. OK, everybody stand up.
2. Simon says, stand up.
3. 'Cher says, stand up.
4. Sit down.
5. 'Cher says, everybody look to the left.
6. 'Cher says, everybody look to the right.
7. Can you feel that? We're paying with love tonight! It's not about the...I'll stop singing now.
8. OK, look front.
9. 'Cher says, look front.
10. Let's take this up a notch. 'Cher says, for the next 10 instructions, when I say "stand up" you must sit down, and when I say "sit down" you must stand up. These instructions will not be preceded by "'Cher Says." Ready?
11. Stand up.
12. Sit down.
13. Stand up.
14. Stand up.
15. Sit down.
16. Stand up. 
17. Sit. That was 7 instructions.
18. Stand up.
19. Stand up.
20. Sit down.
21. Stand up.

Would you have sat down on instruction 21? Well, you would have been out because that's the 11th instruction, and since I did not say "'Cher says" you had to do nothing. Only 4 students caught that trick, and they were all awarded prizes.

This game is largely limited only by your imagination, and a variety of tasks that test logic, dexterity or teamwork can be instructed to the players. I had a whole bunch of other tricks up my sleeve (e.g., "'Cher says, raise a prime number of hands." How many hands would you raise?), but didn't get to use them. In fact, I had prepared a slide with a number of random items on it (like a cake with 3 candles, a cat, etc.) and intended to show it to the players for 10 seconds. I would then give instructions based on the slide (e.g., "raise a number of fingers equal to the number of candles on the cake"). It is also possible to give instructions based on an audio clue, or get players to play little mini-games ("'Cher says, win a game of rock-paper-scissors with a person next to you." Note that the players can play more than one game!). Just make sure to phrase your instructions clearly and concisely so that there is no room for misinterpretation, and then let your inner troll run wild.

(source: http://knowyourmeme.com/memes/trollface-coolface-problem)

By the way, you know that instruction to raise a number of fingers equal to the number of candles on the cake? I didn't say "'Cher says." Did you catch that?

Classroom game: Werewolf

Last week, I was involved in an activity for the Ngee Ann Polytechnic Board Games Club (NPBGC). The idea was to host a game for a number of Asian Nursing students from non-English speaking countries like China, Vietnam and Myanmar. The students were divided into four groups of about 18 students each, and we had around 25 minutes with each class. Also, the game should promote communication in English (or whatever version of English we happen to speak in Singapore). Given these constraints, we pretty much immediately settled on running Werewolf.

It's clearly a family game.
(Image from http://boardgamegeek.com/image/1534745/ultimate-werewolf-ultimate-edition)

In Werewolf, the players take the roles of villagers. One morning, the villagers wake up and discover that the mayor has been murdered in the night. There are werewolves in the village! At the start of the game, every player is dealt a card that is kept secret from the other players. If your card says "villager", your aim is to kill all the werewolves before everybody gets eaten. If your card says "werewolf", your objective is to kill enough villagers until there are only as many villagers as werewolves, whereupon you rise up for an all-you-can-eat villager buffet with doggy bags. There is also a special villager called a "seer" who acts as a sort of spirit guide for the village (if she survives, that is). Finally, there is a referee controlling the action (i.e., me).

The game plays in alternating "Night" and "Day" turns. At night, all the players close their eyes. The referee then instructs, "werewolves open your eyes," so the werewolves know who their allies are on the first night. On any night other than the first, the werewolves would silently decide on one villager to kill (by pointing to her), and then they close their eyes again. The next instruction is "seer open your eyes and point to someone you wish to know about." When the seer selects a player, the referee silently indicates to the seer whether the player is a villager or a werewolf using a previously explained hand signal. Finally, the seer closes her eyes, and then day begins, whereupon the werewolves' victim is notified of her grisly fate.

During the day, the villagers get to select one among their number for lynching (isn't this game wholesome?). If a player is accused of being a werewolf and someone else seconds the accusation, then the accused gets about a minute to defend herself; here is where the ability to make a convincing argument (in English) could save your life. At the end of the defence, all the villagers vote simultaneously with either a thumbs up or a thumbs down to decide whether the accused gets to live; a majority "nay" vote and the villager is summarily executed by the mob, and then she reveals her role. If she's a werewolf, there're celebrations and congratulations all round; if she's a villager, then an innocent person has been killed by an unthinking mob, and the werewolves are that much closer to winning.

On the whole, the game was a success. At the start, I needed to prompt them a bit, but these Nursing students are a pretty canny lot and they picked up the strategies for the different roles very quickly. Early in the game, the defence put up by the accused is pretty weak (e.g., "I'm a kind person", "I'm a vegetarian", or, my personal favourite, "I am a villager"), and they're invariably toast. As the game progressed, the arguments became more elaborate and convincing. In one game, a particular student was accused twice and spared twice. Once, she saved herself by telling her accuser, "if I am a villager and you kill me, you should be killed next," which certainly gave everyone pause.

She was a werewolf. (Awesome!)

Werewolf is a combination of deduction and role-playing. If the aim is to help foster communication skills, it's  an excellent game if the referee is active in prompting for responses, e.g., "why do you think she's a werewolf?", "is that all you want to say in your defence? Remember, your life is on the line!" It's also just a fun game that is suitable for a classroom of around 20 people, just to bring people out of their shell.

Oh, and all you need to play Werewolf is a few slips of paper with the words "werewolf", "villager" and "seer" on them. The standard Werewolf is a public domain game, while Ultimate Werewolf pictured above provides cards for up to 68 (!!!) players along with several fun new roles.

Some other lessons learnt:

• Try not to be the only male in a class full of females. Twice, the sole male was the first on lynched. Coincidence?
• I should have put my cards in card sleeves for protection. Students tend to clutch the cards when they're excited, and I ended up with a bunch of crumpled cards. Not that I mind all that much - it's nice to see the students so emotionally invested in the game.
• Talking non-stop for two hours is hell for the throat, especially if you're trying to keep order in the midst of flying accusations. Fun, though.

What's the deal with board games?

As part of the Staff Bonding Committee, I organized a one-and-a-half hour board game session for my colleagues last week. The main aim of the session was to get everyone together to socialize, enjoy themselves by playing some board games and get to know each other a little better.

Sounds boring, right? A bunch of working acquaintances forced by an over-zealous committee (probably formed by a manager who has read Happy Workplace Management for Dummies one too many times) to play Monopoly? It's like going through Chinese water torture, except that you're also forced to make awkward small talk.

Well, another objective of the session was to show my colleagues that tabletop gaming is not Monopoly, and there are literally thousands of better board games out there. Objectively speaking, Monopoly is a terrible game. You can't really affect the outcome of the game because there are almost no useful decisions to make (it's pretty much always a good idea to buy any property you land on), so you're completely at the mercy of your die rolls. In terms of useful decisions, Monopoly is in the same category as Snakes & Ladders, Battleship and flipping a coin, except that you have to do it for hours if not days (pop quiz: how long was the longest Monopoly game ever played?). Ain't nobody got time for that.

Listen, if you just feel like spending a couple of hours rolling dice and moving a top hat around the board with a couple of like-minded friends, by all means go ahead. Maybe you sometimes need to switch your brain off for a while, and who am I to judge? However, if you feel that board gaming is boring based on the faulty assumption that all board games are like Monopoly (or Risk, or Chess, or Cluedo), you could be missing out on something that you'd really enjoy. This is the curse that Monopoly has wrought on the board gaming hobby.

"All who think of board games shall think of me! Muahahahaha!"
(sources: http://www.thelmagazine.com/binary/a429/1251222802-moneybags.jpg,
http://en.wikipedia.org/wiki/File:MargaretHamiltoninTheWizardOfOz.jpg)

To give you an idea of the possibilities behind board games, let me briefly describe the game that got me into this hobby. It all started in 1999 when a good friend hosted my wife and me on our honeymoon in Melbourne at his house. When we got there, we saw a board game on the dining room table and got curious, so we asked him to explain the rules to us (on hindsight, I think my friend planted the game there with an ulterior motive). The game was called The Settlers of Catan. 

"Who has wood for my sheep?" - Sheldon Cooper, The Big Bang Theory
(source: http://boardgamegeek.com/image/268855/the-settlers-of-catan?size=original)

The board is modular and made out of individual hexagons that are randomised for every game, as are the numbers on the hexes. You begin the game with two settlements. The aim of the game is to be the first player to get to 10 points, which you achieve by building roads, settlements and cities using resources. Two dice are rolled every turn, and the number rolled determines which hexes produce resources; if you have a settlement or city adjacent to such a hex, you get that resource. Therefore, it is better to build your settlements next to hexes with more probable numbers (e.g., 6 or 8) instead of the improbably numbers (e.g., 2 or 12).

Each turn you can also trade resources with other players, or trade four of one type of resource for one of another. If you have a settlement or city next to a port, you get a better trade ratio, but since ports are on the edge of the board, the settlement will be adjacent to at most two hexes (compared to three hexes for an internal settlement). The trading aspect is a major part of the game, which requires creating temporary alliances and negotiating mutually beneficial trades. There are a few other mechanics in the game (like the dastardly Robber that steals stuff when a 7 is rolled, or development cards you can buy for a one-time boost), but this is mainly how the game is played.

Wow. For a guy whose previous experience with board games came solely from Parker Brothers, this game blew my mind. Just by having the rules explained to me, I immediately thought of a bunch of tactics and strategies. Do I prioritise getting wood and brick to build roads early (required to expand since settlements can't be built too close together), or just go for the most probable numbers and trade for the wood and brick I need? Is it worth having a port settlement? Should I get a wood for his sheep? (Sorry, had to throw that one in there)

If you're not particularly inspired by my description of The Settlers of Catan to try playing board games, I'm not surprised. There is a vast difference between reading a description of a game on your monitor and actually seeing and playing the game. The objective of my post is just to explain that there are thousands of board games out there that are much, much better than Monopoly (and some of them don't even require boards). If you are at all interested in getting together with a few friends around a coffee table for a fun social activity, where you get to talk, taunt and laugh at each other, then you might want to look into the board gaming hobby. It's an alternative to watching a movie or playing an online game.

As for the staff bonding session, I got a decent turnout of about 20 people, and I think quite a number of them had fun. Admittedly, I suspect a few of my colleagues did not quite get into it, but I appreciate them for giving the games a try. For this first session I focused on party games and other lighter fair, and I wasn't afraid to toss a few silly "children's" games into the mix. For the record, the games that saw play were:

• Rattlesnake (something I threw out for early arrivals as I set up the other games; helped to blow the "board games = Monopoly" mindset out of the water)
• Liar's Dice (the big hit of the party; saw constant play throughout the session)
• Dixit and Dixit Odyssey (very much enjoyed by one group, less so by another)
• Say Anything and Say Anything Family Edition (played by two groups with moderate success)
• Squint (didn't work too well for some reason)
• For Sale (quick and fun)
• Martian Dice (note: it is interesting to see math lecturers arguing probabilities as they play)

Epilogue: We got permission to hold another board gaming session, and this could potentially be a monthly affair. Any gamers reading this with suggestions for suitable games for the next session, please comment below!

My teaching style

In order to be successful at anything, you have to play to your strengths and downplay your weaknesses. Being an effective lecturer is no exception. There are several tried and tested styles of teaching that have been proven effective for other people. Unfortunately, none of them are entirely suitable for me.

For example, there is the disciplinarian. These educators lay down the ground rules along with the penalties for breaking them, enforce them strictly, and impress the students with integrity and fairness. The rules usually relate to professionalism issues like punctuality and in-class behaviour. When the students follow the rules, it creates an atmosphere that is conducive to learning. The best practitioners of the disciplinarian approach are also excellent communicators who are able to deliver their material in an engaging manner, so that eventually the students want to listen and following the rules is no longer a chore.

A classic disciplinarian educator. Notice the smouldering glare. Staring deep. Into your soul.
(source: www.imdb.com)

I am poorly suited to the disciplinarian approach. I'm just really bad at keeping a serious tone when scolding someone, so I'm not an effective scolder. It's also difficult to come up with a punishment that is proportional to the crime. Suppose a student is late; other than marking him absent, what else would be an appropriate punishment? Taking marks off seems too harsh, and barring him from the class defeats the purpose of getting him to learn. Me, I just pause the class and greet the tardy student as brightly as possible, and hopefully his classmates will heckle him a bit.

Another method is to be a dynamic educator, to come up with some interesting and innovative hook that keeps the students coming back for more. If you're an ex-marine, you could display your karate skills. If you're an award-winning stand-up comedian, you could teach MacBeth using your John Wayne impersonation. Or, if you're like one of the lecturers here at Ngee Ann Poly, you could entertain the students with magic tricks (seriously - and by all accounts, he's an effective and well-liked lecturer).

Dynamic educators. The fact that a student died in all three movies is probably a coincidence. Right?
(source: www.imdb.com)

Being a dynamic educator is pretty tiring because you need to constantly keep it fresh with new and engaging tactics. There are excellent lecturers who have a complete utility belt of tactics that they employ with ease, including the use of technology, activities, audio and visual materials, etc. I'm trying to be more dynamic in my teaching (e.g., by using games), but I'm not there yet.

Of course, it helps if you look like Sidney Poitier, Michelle Pfeiffer or Robin Williams. Me, I'm a 1.62m (5 ft 4 in) nerdy guy with glasses who looks barely out of puberty. Some educators overcome this problem by being an expert. The expert educator is an authority in the subject, and the students feel honoured just to have the opportunity to tap his wisdom. This works best if you've created a seminal work on the subject, or have a theorem or mathematical constant named after you, or had your life story made into a movie by HBO. Unfortunately, I'm just not that smart.

An expert educator. At everything.
(source: http://en.wikipedia.org/wiki/File:Stephen_Hawking.StarChild.jpg)

Therefore, I had to develop my own style of teaching, which I call the excited puppy. Allow me to explain.

One of the main elements of my teaching philosophy is to be enthusiastic when delivering the material. The idea is to try to show the students that the concept being taught is fun and exciting, thereby raising the energy levels of otherwise uninterested students who would much rather be scrolling through Facebook. I do this by giving examples of ways to apply the concepts to real-life situations so that the students can better imagine their applicability. Furthermore, I don't mind overselling the "coolness" of the material and making a bit of a fool of myself if it keeps my students' attention.

My inspiration.
(source: http://www.chumpysclipart.com/)

I suspect I take this tactic to extremes sometimes. I actually use the word "cool." I gesticulate in a way that justifies the use of the word "gesticulate". I have even been known to unconsciously perform a little hopping dance in the midst of a particularly enthusiastic exposition. A good friend of mine, Prof Michael Jahn, once said of my teaching style that "you are so enthusiastic when you teach that the students just get carried along for the ride." Or, as an amused and bemused Computing Mathematics student so succinctly put it last year, "why are you so funny?"

The excited puppy strategy suits me perfectly. My less-than-mature looks are actually an advantage, because if someone who looks like Lee Kuan Yew acted the way I do, it would look incongruous and possibly creepy. This strategy also provides a solution to my inability to scold people; instead of showing displeasure at a transgressing student, I show my disappointment. If I do it properly (I stop just short of actually giving a sad puppy whine), hopefully the student feels enough guilt that he'll correct his behaviour in the future. Nobody likes to disappoint an excited puppy.

"Was it something I did?"
(sources: http://knowyourmeme.com/memes/okay-guy; http://www.123rf.com/photo_10120743_sad-puppy.html)

In all seriousness, the way I teach is not a calculated tactic. This is simply the way I naturally act, and it just happens to have some benefits. I think the main difference between my teaching style and most other lecturers is the fact that I de-emphasize the teacher-student divide, i.e., I don't act like the boss of the classroom. I prefer to conduct a lesson as a collaborative effort, where everybody's working together to achieve the objective of learning the material. Nothing would make me happier than giving A-pluses to everyone, and I want the students to know that.

That's why I'm so "funny".

Classroom game: Wits & Wagers

At the end of my first Advanced Object-Oriented Analysis and Design (AOOAD) lessons back in October 2012, I divided the students into groups of 3 or 4 and played the party game Wits & Wagers:

Image from http://boardgamegeek.com/image/521431/wits-wagers

Wits & Wagers is a trivia game with a twist (you can get the official rules here). All the answers to the questions are in the form of numbers (e.g., In centimetres, how tall is Yao Ming?), and the questions are difficult or obscure enough that nobody is likely to know the exact answer. The participants try to guess a value that is as close to the correct answer as possible without going over, and they each write down their guess on a small erasable board,. The answers are then arranged in ascending order, and each answer is assigned a payout (e.g., 2:1 or 3:1); the highest and lowest guesses pay out more than the middle-of-the-road guesses.

Here's the clever bit: the participants then get to wager on up to two answers, and they don't have to bet on their own answer. If the answer you bet on is the closest without going over, you get the corresponding payout (the one who made the closest guess also gets 3 bonus points).

This game is essentially a multiple-choice quiz in disguise, except that the participants come up with the choices themselves. It also mitigates one of the main problems with trivia games, namely the tendency for the class genius to crush everyone else with his savant-like knowledge of trivia, because if you suspect that someone knows the answer, just bet on his answer. It's a really cool mechanic.

Like any trivia game, how fun it is depends heavily on the questions asked. Unfortunately, the questions that come with the commercial game are extremely USA-centric (will you guys go metric already???), so I came up with my own questions. I also spent some time coming up with a nice Powerpoint presentation with a ticking timer for the game (I had some problems with the sound effects though); you can download it here. The most boring question is probably Question 2, which is the only question that related directly to AOOAD, but hey, I had to toss a relevant question in there, right?

How did my students like it? Well, the response was generally positive I think. There were a few students who didn't really participate, but those who did seemed to have a good time. I might make a few changes if I do this again though. For one thing, I would allow more than 45 seconds for guessing and 30 seconds for bidding. I might also use the Wits & Wagers Party Edition rules instead, which simplifies the payout process.

All in all, the game did ok. I admit that it wasn't a great match for AOOAD, and would probably work better for a topic where more questions with numeric answers could be asked (e.g., math). I'm not teaching Computing Mathematics this upcoming semester, but I suspect Wits & Wagers would be a better fit there ("Given these 200 numbers, what is the mean? You have 45 seconds...").

What is love?

(...baby don't hurt me, don't hurt me no more...)

I've only ever been in one relationship; my wife and I got together when I was 16 and she was 14, and we've been together ever since. We've had our share of ups and downs, but we've never really even had a serious quarrel. Honestly, we're disgustingly happy.

Maybe that's why I've had quite a few people seek me out for relationship advice. Well, I haven't done any research or anything, but I've got a very simple Theory of Love(tm) that is composed of two parts, which I will be sharing in this post. For ease of discourse, my pronouns assume that I'm talking to a guy who's possibly in love with a girl.

Here's Part One of my Theory of Love: "When you love someone, making her happy makes you happy."

Read that sentence again. It is VERY different from "You're happy when you're with her." The key is that when you're in love, your happiness is tied to her happiness, not her looks or her actions or whatever. There is nothing wrong with enjoying someone's company, but if you love her, you'd enjoy doing things to please her, because seeing her happy makes you happy. Naturally, seeing her sad makes you sad. If you enjoy going out with her to a party, that's fine. But if she wants to leave because she's got a bad headache and you'd rather stay than send her safely home, maybe it's time to re-evaluate the relationship.

Here's Part Two of my Theory of Love, which is just as important as Part One: "The relationship only works if she feels the same way."

Duh, right? Well, it's amazing how many people forget this part. I see many budding relationships where both parties are happy: he's happy because she's happy, but she's happy because he's doing stuff to make her happy. Unfortunately, she isn't really interested in making him happy, or at least she wouldn't go out of her way to do so. I'm not saying that the girl in this scenario is the villain of the piece. Most likely she is just enjoying herself and not analyzing things too closely.

If both parties feel the same way, then the relationship has every chance of working. Take the example of a guy I know who had a smoking habit of 100 sticks a day. His wife doesn't smoke and hates it when he does, so she wants him to quit. Since he loves his wife, he's willing to try his best to at least cut down; last I checked, he's down to 10 sticks a day. Since his wife loves him, and she knows how difficult it is for him to quit, she encourages him when she can and isn't too hard on him if he needs to puff a stick or two after a stressful day.

See how this works? It's just making mutual compromises because both parties want each other to be happy. And that, to me, is love.

Classroom game: Smarty Party

In the final tutorial session of the semester for my Advanced Object-Oriented Analysis and Design (AOOAD) classes, I decided to run a trivia game adapted from the commercial boardgame Smarty Party.

Image from http://boardgamegeek.com/image/72266/smarty-party?size=original

The rules are simple: I provide a category that describes a list (e.g., Best Picture Academy Award Winners 2000-2011). On their turn, each student (or team of students) has to try to name one item on the list. A student who makes a guess that is not on the list gets a number of penalty points. The sequence of penalty points is 3, 2, 2, 1, 1, 1, 1 (i.e., the first to miss gets 3 penalty points, the second gets 2, and so on). The round is over when there have been 7 misses or all items in the list have been guessed. The winner is the one with fewest penalty points at the end of the game.

For this game, I prepared a Word document with 5 lists. The colour of the text for the entries is white. When a student guesses an answer, I highlight the corresponding entry and change the text colour to black in order to reveal it. I also printed out the document so that I know which entry is which. Overall, the game took about half an hour.

The success of this game depends heavily on the categories chosen. I did my best to make sure the categories were age- and culture- appropriate because nothing is more boring than a trivia game where you don't know any of the answers, or worse yet, where you get crushed by some know-it-all. Even so, it turns out that not many of my students were movie buffs who knew about the Oscars ("no, the Fast and the Furious never won Best Picture"), so I'll probably replace that category if I run this again.

Because it's the final session for the semester, my objective was mainly to let the students have a good time, so all the categories were somewhat whimsical. I was particularly interested in the students' responses for the Teaching Award Winners category (these are second-year students) because it let me know whom they felt were good lecturers. I think some of the students were genuinely surprised that some of their favourite lecturers never won the Teaching Award. However, this game is one way that you can test the students' recall ability in class. You can conceivably ask nursing students for the warning signs of shock, or chemistry students for the first 20 elements in the periodic table. My advice, though, is to not have the entire game involve serious topics, because after the first couple the students will figure out that it's just a thinly disguised review exercise and lose interest.

For the record, the winners were...I honestly don't remember (any of my students reading this are welcome to remind me in the comments section). What I do remember is lots of laughter amid cries of "you stole my answer!" and good-natured ridiculing of desperate shots in the dark as the obvious guesses were taken. If nothing else, my students now know that the most viewed youtube videos are not necessarily the best ones. :)