Which of the following features are indicative of random errors? So the first option, doing numerous measurements and taking the average to minimize any errors. Remember we talked about this up above. Random errors are unpredictable. On the same scale that you're measuring something, you may get a total that's 1 gram too high, and then another instance it may give you a measurement that's 2 grams too light. It's always fluctuating between being too much or too low. Here, a way to minimize random error is to take numerous measurements and then take the overall average of those measurements. So yes, this is indicative of a random error. So we know that option 1 is at least true.

The results of an experiment are consistently greater than expected or less than expected. Here it's saying consistently. Consistently would imply that it's a predictable outcome. So this would indicate that we have a systematic error. Remember, systematic errors will consistently give us a value that's greater than expected or less than expected. Never both. So, this would not be an option.

Refining the parameters of the experiments helps eliminate any errors. Now remember, a random error is unpredictable. So there's nothing really we can do ourselves to stop it from happening. All we can do is help to minimize random error by taking several measurements. Here, if we're going to redefine or refine the parameters, that means that we're dealing with a systematic error. One reason that systematic errors occur is that the design of the experiment may be flawed. So we go back and we tweak it a bit to make it better. This helps to eliminate systematic errors.

Finally, the existence of the error is hard to determine. Here it's easy to see that we have a random error. You measure something several times, and you get numbers that are too high and too low. It's always fluctuating back and forth between being too high or too low. We know that's not normal, so we know there's a problem there. A systematic error, though, will consistently give us a number that's too high or give us a number that's too low. Because it's consistently doing this, it's hard for us to determine if an error does occur or not. So this would be indicative of a systematic error. So, out of my four options, only option 1 represents random error.

Now that we've done this example, try to do the final one. See if you get the same answer that I get when you come back and take a look at my explanation.