I bought a set of tires from Neal Tire and Auto Service in Mattoon, Illinois. I needed tires in a hurry, and after calling around this was the place with the best price on the tires I needed. An acquaintance, an elderly widow, had trouble with them not replacing her oil drain plug after an oil change. They had made good on that mistake somehow, I told myself. Hey, mistakes happen.
So it was time to get the tires rotated and oil changed. Neil Tire and Auto Service in Mattoon, Illinois assured me at the time I bought the tires that they would use the Mobil 1 full synthetic oil in my diesel Jetta. I had noticed what felt like tire balance issues at highway speed. I made an appointment for 2pm, allowing 3 hours before my next schedule item at 5pm. I thought I could get home for a while after the oil change. I mean, three hours?
So I took my lunch in to the waiting area. An older lady, well-dressed and hair coiffured, sat reading the newspaper.
Two hours in, they told me they were having trouble getting the lug nuts off. I could hear the pneumatic wrench grinding away. I wondered if I should have brought a cot. I also wondered how well they would balance the tires, since closing time was coming up and there were people waiting.
The old woman was snoring quietly in the waiting room.
After it was done, with 45 minutes left before 5pm, they told me the price, and it was $30 less than I expected. I asked what kind of oil they used. They told me they'd used Rotella. Why didn't they use synthetic? Blank look. "We always use Rotella on diesels." Realizing that the engine had had full synthetic in it since it rolled off the lot, I dropped the F-bomb. Why didn't they use Mobil 1? The clerk was polite, despite my obvious anger. Same blank look. "We always use Rotella on diesels. "
Every other place I've taken my Jetta to have the oil changed has warned me to use full synthetic.
Mobil 1 is listed on their in-store advertising, but Rotella is not.
After consultation with my wife, who's a lot tougher about stuff like this than I am, I said I wanted them to replace the oil with Mobil 1, and no, I wasn't going to pay the difference. "We always use Rotella -- I think that's good enough", he repeated with a shrug. Still, they went ahead and changed it, and didn't charge me extra.
That's the last time I get my oil changed there. I will even pay to have someone else rotate the tires I bought from Neil Tire and Auto Service in Mattoon, Illinois, because I think they're nice, but incompetent.
Showing posts with label reviews. Show all posts
Showing posts with label reviews. Show all posts
Thursday, February 26, 2009
Tuesday, December 11, 2007
How to win on Deal or No Deal
[Originally blogged 2006-03-26, updated 2007-12-11 (see below)]
NBC's vapid, but fun, game show Deal or No Deal seems simple enough. I doubt it will be the next Wheel of Fortune, or even the next Weakest Link, but stranger things have happened.
The contestant picks a suitcase out of 26 held up by scantily clad models. A board shows amounts, from 1 penny up to ONE MILLION DOLLARS (-oooh-). The contestant gets to pick some more, revealing the amounts held in them -- will it be ONE MILLION DOLLARS (-oooh-)? The contestant is given the choice to keep the suitcase he has, and win its contents, or go on picking others.
How to decide?
The answer is with expected value, a principle of mathematics that sounds fancy but in this case requires only simple arithmetic.
Expected value normally means finding the sum of all possible outcomes multiplied by their individual probability. It can get unwieldy, but in this simple case the odds of the outcomes are all the same, 1/N, where N is the number of values left on the board.
At any given step, add the total amount left on the board, and divide by the number of entries left. Since each amount left has equal chance of being in any of the suitcases, including your own, the expected value for a given suitcase is just the average.
When the banker calls, if your expected value if you remain in the game is higher than his offer, reject it. If his offer is higher or the same as the expected value, take it.
For instance, suppose you have entries on the board (three suitcases and your own). The amounts are $100,000, $50,000, $10, and $.01. The penny looks scary, but the $100k looks tempting. What to do?
The total is $150,010.01, which you round to $150k for an average of about $37,500. If the banker calls with an offer: $35,000, you should reject the offer. If the offer is $38,000, take it.
The reason this is the best strategy is that if you played the game many, many times, on average you'd win the expected value of what's left.
[Update: After watching this show off and on for a few months, I realized two things. First, the show did become the next Weakest Link. Secondly, simply math wasn't enough to provide a winning strategy, and in fact isn't really needed.
To win, you have to define "winning". There are two kinds of winning: winning lottery-big (a life-altering amount), and walking out with a respectable prize, one that will solve some immediate problems for you: let you open a business, buy/pay off the house, take a less stressful job, whatever.
So that gives us three kinds of numbers the cases can hold:
Think about the end game: you have some small prizes and two big ones, $100,000 and $400,000. If you open a case with a small number, your offer will go up; keep going. Even if you open the $100,000 case, your offer will still not go down that much, and you can accept it with glee. Only if you choose the highest of the lottery amounts will your offer go down significantly, and you walk away with a nice paycheck.
If you reject the offer when you have only one lottery prize left, you risk coming away with nothing when you have a very easy way (at that point) to solve some problems for yourself. If you only have one big amount left on the board, make the Deal.
]
NBC's vapid, but fun, game show Deal or No Deal seems simple enough. I doubt it will be the next Wheel of Fortune, or even the next Weakest Link, but stranger things have happened.
The contestant picks a suitcase out of 26 held up by scantily clad models. A board shows amounts, from 1 penny up to ONE MILLION DOLLARS (-oooh-). The contestant gets to pick some more, revealing the amounts held in them -- will it be ONE MILLION DOLLARS (-oooh-)? The contestant is given the choice to keep the suitcase he has, and win its contents, or go on picking others.
How to decide?
The answer is with expected value, a principle of mathematics that sounds fancy but in this case requires only simple arithmetic.
Expected value normally means finding the sum of all possible outcomes multiplied by their individual probability. It can get unwieldy, but in this simple case the odds of the outcomes are all the same, 1/N, where N is the number of values left on the board.
At any given step, add the total amount left on the board, and divide by the number of entries left. Since each amount left has equal chance of being in any of the suitcases, including your own, the expected value for a given suitcase is just the average.
When the banker calls, if your expected value if you remain in the game is higher than his offer, reject it. If his offer is higher or the same as the expected value, take it.
For instance, suppose you have entries on the board (three suitcases and your own). The amounts are $100,000, $50,000, $10, and $.01. The penny looks scary, but the $100k looks tempting. What to do?
The total is $150,010.01, which you round to $150k for an average of about $37,500. If the banker calls with an offer: $35,000, you should reject the offer. If the offer is $38,000, take it.
The reason this is the best strategy is that if you played the game many, many times, on average you'd win the expected value of what's left.
[Update: After watching this show off and on for a few months, I realized two things. First, the show did become the next Weakest Link. Secondly, simply math wasn't enough to provide a winning strategy, and in fact isn't really needed.
To win, you have to define "winning". There are two kinds of winning: winning lottery-big (a life-altering amount), and walking out with a respectable prize, one that will solve some immediate problems for you: let you open a business, buy/pay off the house, take a less stressful job, whatever.
So that gives us three kinds of numbers the cases can hold:
- Small: lower than your "respectable" win
- Respectable: At or higher than your "respectable" expectation
- Lottery: A number big enough to make your offer close to respectable.
Think about the end game: you have some small prizes and two big ones, $100,000 and $400,000. If you open a case with a small number, your offer will go up; keep going. Even if you open the $100,000 case, your offer will still not go down that much, and you can accept it with glee. Only if you choose the highest of the lottery amounts will your offer go down significantly, and you walk away with a nice paycheck.
If you reject the offer when you have only one lottery prize left, you risk coming away with nothing when you have a very easy way (at that point) to solve some problems for yourself. If you only have one big amount left on the board, make the Deal.
]
Thursday, September 20, 2007
Why not to buy an LCD TV
When the Microvision Pico Projector technology spreads and stabilizes, you won't need a screen, just a white wall.
Though I'm told they do it all with mirrors.
Though I'm told they do it all with mirrors.
Tuesday, September 18, 2007
Paperless Voting Logic Errors
The Information Technology & Innovation Institute has published their report (pdf) on electronic voting, and as advertised in their press release last week, they think a paper trail is unneeded and even harmful. To this end their report employs a series of logical fallacies, hinting that their research began with a premise and attempted to validate it, rather than simply seeking the facts.
The biggest mistake the report makes is a result of the incorrect assumption that all-electronic voting is a worthwhile goal. It fails to think outside the box created by that assumption, which would have revealed a better solution.
The report begins
The fallacies fly beginning with the opening three words: "Americans trust computers" relies on an Appeal to Popularity, and Ambiguity in the words "trust" and "computers". A report intending to provide technical background and subject-matter expertise should not rely on public opinion for its primary argument. That Americans believe a certain thing does not make it true, unless we are talking about the definition of words or something else which is made true by popular acceptance. While "trust" has a variety of meanings to politicians, it has a more specific meaning in the field of computer security and information assurance. That something is trusted means only that its level of insecurity is acceptable, not that it is perfect. And the computers and most importantly the ways they are connected in banking, medicine, and aviation are markedly different than voting machines.
So the report begins by asserting that the paper trail debate is only about trusting computers, even unleashing against those who want a paper trail the ad hominem "technophobic", when in fact there is far more to it than trusting computers. It is about designing a process that doesn't require trusting computers. Many of us seeing the need for a paper trail are among the least technophobic people there are, knowing exactly when to trust a computer and when not to do so.
Most of the report sets up paper-only ballots as a sinister straw man, bringing up the history of paper ballots (e.g., with the sidebar: "How LBJ Stole and Election with Paper Ballots") and insisting that anyone opposed to direct-record electronic (DRE) voting machines must be for that kind of corruption and inefficiency.
Despite the imprecise terminology (misusing the word "vote" for "ballot"), the electronic "guarantees" provided to the voter are not worth the paper they aren't printed on. The guarantees all require trusting the system, which is exactly what we are trying to establish. This is known as "begging the question".
The report goes even further, however, and makes a misstatement of fact, saying "The third property, that the vote was tallied as recorded, is not provided by voter-verified paper audit trails." In fact it is precisely this property which a paper trail provides.
An machine which prints the official ballot and sends an electronic copy to a central location can be far more secure and trustworthy than an all-electronic one. If each voter, or a statistically important sample of them, inspects his paper ballot, then the tally of the paper ballots had better match the electronic one. The reason is this: the ballot box could be compromised, and the electronic data could be compromised, but the task of compromising them both in the same way is exceedingly difficult, equivalent to compromising everyone and everything involved. DRE systems as recommended by this report are incapable of that level of assurance.
All-electronic voting can never be as secure, and especially not as robust, possibly even as paper-only but especially not a hybrid of both. This report may have concluded that if it had not begun with its conclusion already fixed in place.
The biggest mistake the report makes is a result of the incorrect assumption that all-electronic voting is a worthwhile goal. It fails to think outside the box created by that assumption, which would have revealed a better solution.
The report begins
Americans trust computers to run critical applications in fields such as banking, medicine, and aviation, but a growing technophobic movement believes that no computer can be trusted for electronic voting.The report could have ended with its conclusion that a computer could be trusted for electronic voting, and saved us all the trouble, but unfortunately it did not.
The fallacies fly beginning with the opening three words: "Americans trust computers" relies on an Appeal to Popularity, and Ambiguity in the words "trust" and "computers". A report intending to provide technical background and subject-matter expertise should not rely on public opinion for its primary argument. That Americans believe a certain thing does not make it true, unless we are talking about the definition of words or something else which is made true by popular acceptance. While "trust" has a variety of meanings to politicians, it has a more specific meaning in the field of computer security and information assurance. That something is trusted means only that its level of insecurity is acceptable, not that it is perfect. And the computers and most importantly the ways they are connected in banking, medicine, and aviation are markedly different than voting machines.
So the report begins by asserting that the paper trail debate is only about trusting computers, even unleashing against those who want a paper trail the ad hominem "technophobic", when in fact there is far more to it than trusting computers. It is about designing a process that doesn't require trusting computers. Many of us seeing the need for a paper trail are among the least technophobic people there are, knowing exactly when to trust a computer and when not to do so.
Most of the report sets up paper-only ballots as a sinister straw man, bringing up the history of paper ballots (e.g., with the sidebar: "How LBJ Stole and Election with Paper Ballots") and insisting that anyone opposed to direct-record electronic (DRE) voting machines must be for that kind of corruption and inefficiency.
Unfortunately, paper-based auditing trails such as these do not allow the voter to verify that the results of an election are accurate. A DRE voting machine can provide up to three different guarantees to a voter: first, that the vote was cast as intended; second, that the vote was recorded as cast; and third, that the vote was tallied as recorded.
Despite the imprecise terminology (misusing the word "vote" for "ballot"), the electronic "guarantees" provided to the voter are not worth the paper they aren't printed on. The guarantees all require trusting the system, which is exactly what we are trying to establish. This is known as "begging the question".
The report goes even further, however, and makes a misstatement of fact, saying "The third property, that the vote was tallied as recorded, is not provided by voter-verified paper audit trails." In fact it is precisely this property which a paper trail provides.
An machine which prints the official ballot and sends an electronic copy to a central location can be far more secure and trustworthy than an all-electronic one. If each voter, or a statistically important sample of them, inspects his paper ballot, then the tally of the paper ballots had better match the electronic one. The reason is this: the ballot box could be compromised, and the electronic data could be compromised, but the task of compromising them both in the same way is exceedingly difficult, equivalent to compromising everyone and everything involved. DRE systems as recommended by this report are incapable of that level of assurance.
All-electronic voting can never be as secure, and especially not as robust, possibly even as paper-only but especially not a hybrid of both. This report may have concluded that if it had not begun with its conclusion already fixed in place.
Sunday, July 15, 2007
Six Flags St. Louis
We went to Six Flags St. Louis on a 90°F July Sunday.
We got there at 9:30am, though the park opens at 10:30. There were about 20 cars ahead of us at the gate, and by the time they opened the gate to let us in the parking lot, there were at least 100 cars waiting. We parked, showed our Internet tickets to the cashier, and then waited until 10:15 at the entrance turnstyles. We made our way toward the first ride of the day, only to be stopped by park security. They held everyone back from the attractions until 10:30.
My take: either open, or don't open. Don't do it halfway. I guess it's their business, though.
While waiting for security to stop their tyranny and allow us to ride the rides, we developed a plan. Security had deputized a couple of pre-teen kids, signified with adhesive label badges. We decided that unless word came soon that we could go into the rest of the park, we would point to the ground and say "Look! A toy!", dash past the distracted kids, and quickly take over the park, allowing us to be the first to ride the rides that day. While demponstrating that move, I didn't realize that an older boy was watching me. He looked for the toy. This could work!
But while we were still laughing at the older kid for actually falling for the trick, the guards relented from their oppression, and we dashed to the first ride.
Mr. Freeze: thrilling, but too short. On the other hand, I could sit and watch the takeoff and landing for hours. We rode it twice.
Batman: Good coaster, but even though you're upside down a lot, there's no weightlessness. The line is always too long.
Ninja: Great coaster. No line, so we went through about 6 times. We found it physically tiring, because this older coaster beats you up. Still, there's lots of air time.
Screamin' Eagle: I was surprised at how much I liked this 30+ year old wooden relic. Once the biggest wooden coaster in the world, this thing is still great. The first time though, a dad was telling his 6- or 7-year-old that the boy was brave enough to ride the Screamin' Eagle. The boy wasn't sure, and whined about Mom not riding. Dad encouraged, saying "You've already been on Ninja and Batman, you can do this one!" I said if he'd been on those, this one would be a piece of cake. I turned to my own son and whispered that I was a big liar, that this was going to kill him. Buuaaa-haah-haah. Especially at the back, you get a lot of floating air time, and the 4000-foot ride is long enough to enjoy. Since it's old, it's not as popular as the newer ones, so we got to go through several times.
(The dad and kid behind us both loved it.)
The Boss: line too long, didn't ride it. Really long wooden coaster, people said it was pretty good.
Tidal Wave: This is a short little water-car ride, the entire object of which is to make a big splash. Yes, you get wet, no matter where you sit. To get really soaked, stand on the bridge overlooking the car as it splashes into the tidal pool. I wrapped my wallet in a little park map, and it stayed dry in my pocket. Wish I'd brought a Zip-lock baggie.
A word about prices: they suck. At Six Flags, everything costs way too much. $7.50 for a turkey thigh seemed like a bargain compared to the $3 bottled water, the $10 32oz sports bottle, and the other overpriced fare. And except for the turkey thigh, which I recommend, the rest of the food was crappy.
We took a bit of a tour of their water park area. Lines, crowds, and everything is $10. Rent an inner tube (required for some attractions) for $10, a locker for $10. At Holiday World / Splashin' Safari in Santa Claus, Indiana, the inner tubes are free.
At Holiday World, the rides are maintained better, the staff is friendlier, and there is free soda all day, every day. It makes for a nicer experience.
Overall, Six Flags has some nice roller coasters, but Holiday World does, too. Given the overall suckiness of Six Flags and their attitude about grabbing every last dime you have, I'll go to Holiday World next time.
(No one paid me to write this, and I'm not affiliated with any theme park or similar competitor)
We got there at 9:30am, though the park opens at 10:30. There were about 20 cars ahead of us at the gate, and by the time they opened the gate to let us in the parking lot, there were at least 100 cars waiting. We parked, showed our Internet tickets to the cashier, and then waited until 10:15 at the entrance turnstyles. We made our way toward the first ride of the day, only to be stopped by park security. They held everyone back from the attractions until 10:30.
My take: either open, or don't open. Don't do it halfway. I guess it's their business, though.
While waiting for security to stop their tyranny and allow us to ride the rides, we developed a plan. Security had deputized a couple of pre-teen kids, signified with adhesive label badges. We decided that unless word came soon that we could go into the rest of the park, we would point to the ground and say "Look! A toy!", dash past the distracted kids, and quickly take over the park, allowing us to be the first to ride the rides that day. While demponstrating that move, I didn't realize that an older boy was watching me. He looked for the toy. This could work!
But while we were still laughing at the older kid for actually falling for the trick, the guards relented from their oppression, and we dashed to the first ride.
Mr. Freeze: thrilling, but too short. On the other hand, I could sit and watch the takeoff and landing for hours. We rode it twice.
Batman: Good coaster, but even though you're upside down a lot, there's no weightlessness. The line is always too long.
Ninja: Great coaster. No line, so we went through about 6 times. We found it physically tiring, because this older coaster beats you up. Still, there's lots of air time.
Screamin' Eagle: I was surprised at how much I liked this 30+ year old wooden relic. Once the biggest wooden coaster in the world, this thing is still great. The first time though, a dad was telling his 6- or 7-year-old that the boy was brave enough to ride the Screamin' Eagle. The boy wasn't sure, and whined about Mom not riding. Dad encouraged, saying "You've already been on Ninja and Batman, you can do this one!" I said if he'd been on those, this one would be a piece of cake. I turned to my own son and whispered that I was a big liar, that this was going to kill him. Buuaaa-haah-haah. Especially at the back, you get a lot of floating air time, and the 4000-foot ride is long enough to enjoy. Since it's old, it's not as popular as the newer ones, so we got to go through several times.
(The dad and kid behind us both loved it.)
The Boss: line too long, didn't ride it. Really long wooden coaster, people said it was pretty good.
Tidal Wave: This is a short little water-car ride, the entire object of which is to make a big splash. Yes, you get wet, no matter where you sit. To get really soaked, stand on the bridge overlooking the car as it splashes into the tidal pool. I wrapped my wallet in a little park map, and it stayed dry in my pocket. Wish I'd brought a Zip-lock baggie.
A word about prices: they suck. At Six Flags, everything costs way too much. $7.50 for a turkey thigh seemed like a bargain compared to the $3 bottled water, the $10 32oz sports bottle, and the other overpriced fare. And except for the turkey thigh, which I recommend, the rest of the food was crappy.
We took a bit of a tour of their water park area. Lines, crowds, and everything is $10. Rent an inner tube (required for some attractions) for $10, a locker for $10. At Holiday World / Splashin' Safari in Santa Claus, Indiana, the inner tubes are free.
At Holiday World, the rides are maintained better, the staff is friendlier, and there is free soda all day, every day. It makes for a nicer experience.
Overall, Six Flags has some nice roller coasters, but Holiday World does, too. Given the overall suckiness of Six Flags and their attitude about grabbing every last dime you have, I'll go to Holiday World next time.
(No one paid me to write this, and I'm not affiliated with any theme park or similar competitor)
Subscribe to:
Posts (Atom)