The focus of the field of statistics is studying data and information while determining how to interpret this information in useful ways. The primary goal of statistics is to collect reliable information and interpret it to learn more about the world around us and the people and things in it. Statistical methods are often applied to questions about nature and society in order to learn more about them, and can also be applied in many different situations and contexts.
You are seemingly always encountering statistics in the media, perhaps in your job, at the doctor's office, etc. Knowing statistics is important when looking at your exam grade and understanding how well you did relative to the rest of the class. Knowledge of statistics is also important when a doctor is explaining that there is a 5% chance that a drug they are prescribing you can have a specific side effect.
Knowing more about statistics and how they are created and analyzed can allows you a greater understanding of these situations and provides a greater ability to interpret the significance of the statistics that you come across.
There are many methods of gathering information and statistics, including:
While you could disclose information simply by observing, using the experimental method is beneficial because it permits us to establish whether there is a cause and effect relationship existing between two things. Take a look at some example of situations that benefit from using the experimental method:
- One would expect that the more time you spend studying, in all likelihood, you're going to get better grades. The experimental method, on the other hand, would track that. You record how much time you spend studying. Then you record the grades that you get and see if you can determine any kind of cause and effect relationship between those two.
By using the experimental approach with these scenarios, you would have the ability to determine whether one element of each pair is causing the other element.
- One expects that the fewer calories they consume, in all likelihood, they're more likely to lose weight. You would engage in the experimental method by tracking those calories and tracking the weight.
- One would expect that the slower a person drives, the better gas mileage they're going to get. How will we actually engage in the experimental method with that? You would simply track how fast we drive, and then track what kind of gas mileage you received.
The elements that are being changed or observed are called variables. The explanatory variable is the element that the experimenter actually changes. The response variable is the element that is observed that may be changing in response to the explanatory variable.
The idea here is that the experimenter will keep careful records and measurements as they make changes to the explanatory variable, and observe how the response variable responds or fails to respond.
With the experimental method, there are eight steps. You are going to go through these eight steps by using the example of taking a specific medication in order to reduce the symptoms of a cold.
Maybe you've had a cold for a while, and you're trying to figure out what medication is going to help you feel better. By using the experimental method, you could actually figure out a methodical way of tracking these results.
The first step is to choose two things that you think might have a cause and effect relationship, where one might be causing the other. In this case, you're choosing a specific medication. You think it has a cause and effect relationship, because if you take that medication, it will make you feel better or relieve the symptoms of a cold.
Step two is to make a guess as to how these elements might have a cause and effect relationship. If you take the medicine twice a day, you would imagine that it's probably going to make you feel better shortly after taking it.
Step three, predict what you think will happen if changes are made to one thing, and how that will affect the other thing based upon your guess. Your prediction is, if I take this medication, I will feel better.
Step four, test your experiment with a prediction by trying to determine if, in fact, the things we are looking at share the cause and effect relationship that was predicted.
Perhaps you're taking the medication for a few days and you don't notice feeling any better, so you stop taking it. Then you record what happens then. If you feel the same or you do feel better, the medication wasn't doing much good. If you feel worse, the medication probably was helping your symptoms.
The fifth step of the experimental method is to analyze the results of the test to determine what the results tell you about the cause and effect relationship between the two variables. The experimenter will analyze the information from step four; they will use statistical tests to determine whether changes in the explanatory variable are, in fact, causing the changes observed in the response variable.
Step six, conclude whether or not the tests showed that the prediction was correct or incorrect. In this case, conclude whether or not taking the medication made you feel better or whether it didn't. While a conclusion may or may not indicate a cause and effect relationship between two things, the results are not absolute. If the environment or things being tested were to change, then the results may no longer be valid, and new tests should be conducted. In a case like this, maybe you were taking more than one medication for the cold. Maybe the second medication was the one affecting it, and not necessarily the first one, or the one you were testing.
Step seven, revise your guess if the prediction was wrong and start from step two. Or if the prediction looks plausible, start testing again from step four to verify your results. In general, it is a good idea to conduct multiple tests, as doing so helps to confirm the prediction when multiple tests show similar results.
Step eight is the final step. Once satisfied, report the findings so that others can review and possibly test it themselves.
Take a look at other example besides the medication and the cold symptoms. Say you're interested in getting to work a little bit earlier than you have been. You've been running late and your boss is kind of frowning at you every time you walk in the door five minutes late.
In order to change that, you're interested in setting your alarm clock a little bit earlier to see if that makes a difference in terms of how late you are to work. In the case like this, by setting the alarm clock just a few minutes earlier every day, you can determine whether or not you would get to work earlier as a result.
In this instance, it would be important to use the experimental method rather than just an observational approach. As you would be able to determine just how much earlier you had to get up in order to get to work earlier, rather than simply just noticing a trend or maybe getting to work early by chance. The experimental method helps us realize if there is a strong cause and effect relationship between two things, whereas just observing still leaves room for speculation on whether or not two things actually do have a cause and effect relationship.
Sometimes we come across explanations of experiments that have already been done, such as studies that have been conducted on new over-the-counter drugs, or surveys regarding how many people consider a particular politician trustworthy. It can be useful in better understanding the experiment and its results if one can recognize the explanatory and response variables.
So let's take a look at a couple different examples here to see if we can identify explanatory and response variables.
Source: This work is adapted from Sophia author Dan Laub.
The quantity whose change is observed as a result of varying the independent variable.
The quantity varied by the person conducting an experiment.