Transcript for:
Understanding the Scientific Method in Research

science often starts when we observe something and it makes us wonder one way to explore the questions we have is to use the scientific method the scientific method creates a framework for logically and systematically experimenting in order to find answers it has several steps including forming a question researching background information making a hypothesis doing an experiment analyzing data and communicating the results in this video we will look at each step of the scientific method in more detail using the science of popping boba juice-filled balls that pop in your mouth as an example formulating the question we want to answer is the first step of the scientific method a scientific question usually starts with who what when where why or how the most important thing about your question is that it must be testable this means it needs to be something that you can do an experiment to figure out so while you might be tempted to ask a general question like how is popping boba made this isn't a good scientific question to answer that question all you need is a recipe instead choose a more specific question like what kinds of liquids can be turned into popping boba or what determines the size and shape of popping boba with these more specific questions we could experiment by testing different liquids or by changing the process by which we make popping boba sometimes you can wonder about something but not know enough about the topic to make a question that is specific and testable that's okay if that happens you can start with a general question go on to step two and then come back and refine your question to make it testable once you know more about the topic step two is doing background research in this step we want to find out as much as possible about our research topic and learn from the experiences of others when doing background research we can find information in many different places we can use books in the library search the internet or ask an expert or specialist questions about the subject we are exploring learning more about the subject helps us to find the best way to do things gives us clues about what data we need to collect or explains how to set up our experiment in our popping boba example we could research different popping boba recipes to find out what ingredients are necessary to turn juice into juice balls we might also want to find out what the purpose of each ingredient is what equipment is used and what factors affect the ability of a liquid to successfully become hopping boba all this information will be helpful for the next steps of the scientific method with the information we have gathered we can move on to step number three which is constructing a hypothesis a hypothesis is an educated guess based on background research about the answer to our question a hypothesis always includes a prediction that is easy to test and measure it's common for the prediction to take the form of if i do this then this will happen for example based on the background research we did for our popping boba project we learned that sodium alginate a key ingredient in some popping boba recipes only thickens in environments that are not too acidic thinking about how this might affect our popping boba we might come up with a hypothesis that says if i use liquids that are very acidic then the popping boba shape will be less spherical once we have made our hypothesis we will test it by designing and carrying out an experiment to do this we first need to identify the variables of the experiment there are usually three different kinds of variables the independent variable is the one and only variable that is changed during the experiment in our popping boba experiment the acidity or ph of a liquid would be a good independent variable that we could change to investigate how acidity affects the shape of the popping boba the dependent variable is the one that is measured during the experiment to determine the effects of the changes we are making in our popping boba experiment we want to know if the shape of the popping boba changes since good popping boba is considered to be spherical or ball like in shape we could measure the longest and shortest dimension or the diameter and height of the popping boba we make it is okay to have more than one dependent variable controlled variables are all the other conditions in the experiment that we want to keep the same in our popping boba experiment the reaction temperature or quantities of each ingredient are some examples of controlled variables by keeping all the controlled variables the same we know that any changes in the height or diameter of the boba are due to the acidity of our juice instead of one of these factors determining the variables of our experiment helps us to come up with an experimental procedure or step-by-step instructions that will allow us to collect the data we need to test our hypothesis a simplified experimental procedure for our popping boba experiment could look like this choose a liquid or food you want to test then follow a step-by-step recipe to make several popping boba balls measure the diameter and the height of each ball using graph paper and finally redo the experiment but change the acidity of the food mixture an important aspect of a scientific experiment is to repeat the experiment for each testing condition several times to make sure that the results are reproducible and not random make sure to carefully record everything you do measure and observe in a lab notebook so that you have a clear record of your experiment taking videos pictures or making drawings is also a good idea when doing our experiment we need to actively ask is the procedure working as we collect our data if the experiment is not working we will need to troubleshoot the procedure and restart the experiment for example we might find that it is really difficult to produce a single drop of food mixture using a syringe this means that we have to rethink our procedure and then redo the experiment for example instead of using a syringe we might try using a medical dropper the goal of conducting the experiment is to collect enough data to confidently determine if our hypothesis is supported or not the next step after we finish our procedure and have collected our data is to review and analyze our data analyzing the data means looking at it in as many ways as we can this includes things like calculating an average for the different trials of our experiment making graphs and evaluating whether or not the collected data is complete of good enough quality and is valid for our popping boba experiment we could make graphs that show how the diameter or height of our popping boba balls change with juice acidity in graphs like these we usually place the independent variable on the x-axis and the dependent variable on the y-axis it is important to label your graphs and results clearly and include their measurement units if our data is sufficient we can then draw conclusions about whether or not our data supports our hypothesis it is okay if our hypothesis is not supported this happens often to scientists sometimes the data leads to more questions and the process starts again with a slightly different question and a new hypothesis the final step of the scientific method is communicating our results this means communicating all of our data and findings in a written report oral presentation or in some other way so that anybody who is interested in making popping boba balls can use our information to optimize their size shape and deliciousness now that you know how the scientific method works you are ready for your next science adventure remember though that questions in some areas of science can be more easily tested than others don't be afraid to modify steps of the scientific method for example if direct experimentation is not possible to test your hypothesis you could use a simulation or mathematical model instead just keep in mind that the goal of your investigation should be to discover cause and effect relationships by asking questions carefully gathering and examining the evidence and seeing if all the available information can be combined into a logical answer if you want to practice the scientific method or need more information visit us at www.sciencebuddies.org where you can find thousands of free hands-on science and engineering projects you