Date: 03/25/2001 at 13:39:09 From: Rita Mazina Subject: Benchmarks What exactly is a benchmark? Could you please show an example? Thank you!
Date: 03/26/2001 at 15:03:55 From: Doctor TWE Subject: Re: Benchmarks Hi Rita - thanks for writing to Dr. Math. A benchmark is a way of comparing two or more things numerically. For example, to compare how efficiently different models of cars use gasoline, the Environmental Protection Agency runs the cars on a test track under controlled conditions, and measures their fuel efficiency. These numbers are called "benchmarks." A Mazda Protege, for example, might be EPA-rated at 30 mpg (miles per gallon) city / 38 mpg highway. A Ford Taurus, on the other hand, might be rated at 22 mpg city / 36 mpg city. What this means is that the Protege got much better gas mileage when they simulated city driving conditions (30 mpg vs. 22 mpg), but only slightly better gas mileage when highway driving conditions were simulated (38 mpg vs. 36 mpg). These numbers are for comparisons. If I was going to buy a new car and wanted one that would get good gas mileage, I'd look at these EPA numbers to see which was better. I'd also have to consider how much of my driving is city driving and how much is highway driving. Once I bought the car, how many miles I got per gallon of gas would depend on my driving habits, the weather, whether I kept the car in good repair, etc. That's why they always say, "your actual mileage may vary" at the end of the commercials. Sometimes (but not always) benchmarks have a "standard" against which other numbers are compared. For example, to compare the processing power of various models of personal computers, PC Magazine will run a set of test software on one particular type of machine. The resulting performance will be assigned a "benchmark" rating of 100, and all other machines tested will be compared to that standard. So a machine that gets a benchmark of 133 is 33% better (more powerful, faster, etc.) than the standard, while a machine that gets a benchmark of 80 is 20% worse than the standard. Of course, how well a machine performs for you depends on what software you're running on it. Again, "your performance may vary." Benchmarks aren't limited to cars and computers. Many institutions use benchmarks to evaluate everything from jet engines to stocks and bonds. In fact, any time you use a standardized testing environment to compare two or more things, you are using a benchmark. I hope this helps. If you have any more questions, write back. - Doctor TWE, The Math Forum http://mathforum.org/dr.math/
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