Scientific Inquiry and the Scientific Method The Way Cool Way Science is Done

What is Science? Science is a process of inquiry. It's a way of knowing. It is a human endeavor to understand and describe the world we live in. That’s great, but HOW ?! What is Science?

“A Process of Inquiry” Process = a series of logical steps Inquiry = an examination into facts or principles; a systematic investigation How is this done?

Thinking like a scientist Observing Using your senses (see, hear, smell, touch, taste?) to gather information. Must be factual and accurate. Written and/or drawn observations are best. You can go about gathering data in one of two ways, through direct observation, or indirect observation.

Thinking like a scientist Direct vs. Indirect Observations Let's say you have been hired by a local dentist to do a study on local candy eating habits in the neighborhoods around his office. Direct observations – you are looking at an actual behavior or occurrence of some event. Example – you observe customers in a store and count how many bags of candy they purchase. Indirect observations – you observe the results of a certain behavior or occurrence of an event. Example – you look through trash cans on garbage day to see how many empty candy bags are in each trash bin.

Thinking like a scientist Qualitative observations – these are descriptions of what we observe. For example, it is hot outside today. (think of the stem for “qualitative” - “quality”) Quantitative Observations - these are measurements of what we observed. For example, it is 90 degrees Fahrenheit outside today. (think of the stem for “quantitative” - “quantity”) Quantitative observations or measurements should be as precise and accurate as possible. Precision = how exact the measurement is. Accuracy = how correct a measurement is.

Thinking like a scientist Inference – a logical explanation of an observation; a conclusion based on evidence and/or previous knowledge. An anomaly is something that deviates from what is standard, normal, or expected.

Think you can? Imagine you are walking through the desert and you come upon these tracks on the ground. What can you infer?

Now what can you infer? Imagine you are walking through the desert and you come upon these tracks.

Now how does your inference change?

The Scientific Method

It all begins with a question. It could be a question about something you observe, or it might be something you are curious about. “How…?” “What…?” “When…?” “Who…?” “Which…?” “Why…?” “Where…?” In order for the scientific method to answer your question, it must be about something you can measure, preferably with a number. Ask Question The Scientific Method

Do background research Don’t reinvent the wheel. Research your topic to find out what others have already done. Research will help you avoid mistakes of the past, and may help you refine your original question and hypothesis, as well as helping you structure your experiment for the best possible results. The Scientific Method

Construct Hypothesis “If I do this (cause), then this will happen (effect). Your hypothesis should be measurable, and it should help you answer your original question. This is where you state what you think will happen. Your hypothesis should be an “if…then…” statement (“cause and effect” ) The Scientific Method

Hypothesis vs. Predictions vs. Inferences The Scientific Method Hypotheses and predictions are similar in that they are trying to guess the outcome of a future event. Both are based on observations and prior knowledge. An hypothesis is an “If……, then…….” statement, whereas a prediction is an “I think….” statement. Hypotheses and predictions differ from inferences in one major way. Can you think what that might be? It’s all about timing. A prediction or hypothesis is a statement about something that hasn’t happened yet, whereas an inference is typically an explanation about an event that event that has already occurred.

Your experiment will determine whether your hypothesis is true or false. It should be a fair test. You make it fair by changing only one variable at a time. Test with an Experiment You should also repeat your experiments several times to make sure that the first results you got were not due to chance. The Scientific Method

Claims & Evidence Draw Conclusions After experiment is complete, compile your data and analyze it to see if you can support your claims with evidence. Hypothesis was correct Hypothesis was incorrect Go to next step Determine why, revise hypothesis or revise experiment, repeat experiment The Scientific Method Remember – Extraordinary claims require extraordinary evidence

Report Results Once your work is complete, write up your experiment in the proper format. In our case, that will be a lab report. We will discuss how to write the lab report later. The Scientific Method

Experimental Design Variables – Factor(s) that are changed in an experiment Remember that a well-written hypothesis is an “If…., then…” statement: “If I do this, then that will happen.” The “this” is the variable that you will change. The “that” is the variable that changes when you change the “this.” Confused? Let’s give them more proper names and take a closer look at each one.

Experimental Design Variables 101 Independent (manipulated) variables - When you design your experiment, you will want to change only one variable, and then observe what happens. The variable you change is the “independent” or “manipulated” variable. Dependent (responding) variable – When you change the independent variable, you will observe how the dependent variable changes. We also call the dependent variable the “responding variable,” since it changes in response to the change you make to the independent variable.

Experimental Design Variables 101 Controlled variables – All other variables in an experiment must stay the same. These are the controlled variables, and you will want to watch them as close as the dependent variable. If for some reason one of your controlled variables changes during an experiment, you will not be able to say that the results you got were not due to the change in the control variable or the change in the independent variable. Finally, all your variables should be measurable. Let’s look at some examples….

Question Which AA battery maintains its voltage for the longest period of time in low, medium, and high current drain devices? Hypothesis Hypothesis: As I test for increasingly longer periods of time, the Energizer AA battery will maintain a higher voltage than other batteries. Variables Independent Variable - Time, how long each battery operates Dependent Variable - Voltage Experimental GroupControlled Variables for Each Group Low current drain Same portable CD player Play the same music track Play at the same volume level Medium current drain Identical flashlight Identical light bulb High current drainSame camera flash All groups Battery size (AA) Constant temperature (A battery works better at a warm temperature.)

Variables Checklist What Makes for Good Variables? Is the independent variable measurable? Can you change the independent variable during the experiment? Have you identified all relevant dependent variables, and are they all caused by and dependent on the independent variable? Are all dependent variable(s) measurable? Have you identified all relevant controlled variables? Can all controlled variables be held at a steady value during the experiment? Yes / No If you have good Variables, you should be able to answer "Yes" to every question below

Patty Power Mr. Krabs wants to make Bikini Bottoms a nicer place to live. He has created a new sauce that he thinks will reduce the production of body gas associated with eating crabby patties from the Krusty Krab. He recruits 100 customers with a history of gas problems. He has 50 of them (Group A) eat crabby patties with the new sauce. The other 50 (Group B) eat crabby patties with sauce that looks just like new sauce but is really just mixture of mayonnaise and food coloring. Both groups were told that they were getting the sauce that would reduce gas production. Two hours after eating the crabby patties, 30 customers in group A reported having fewer gas problems and 8 customers in group B reported having fewer gas problems. Which people are in the control group? What is the independent variable? What is the dependent variable? What should Mr. Krabs’ conclusion be? Why do you think 8 people in group B reported feeling better?

Slimotosis Sponge Bob notices that his pal Gary is suffering from slimotosis, which occurs when the shell develops a nasty slime and gives off a horrible odor. His friend Patrick tells him that rubbing seaweed on the shell is the perfect cure, while Sandy says that drinking Dr. Kelp will be a better cure. Sponge Bob decides to test this cure by rubbing Gary with seaweed for 1 week and having him drink Dr. Kelp. After a week of treatment, the slime is gone and Gary’s shell smells better. What was the initial observation? What is the independent variable? What is the dependent variable? What should Sponge Bob’s conclusion be?

Patty Power Which people are in the control group? Group B What is the independent variable? New sauce What is the dependent variable? Amount of gas What should Mr. Krabs’ conclusion be? The new sauce appears to work as it reduced the amount of gas produced in60% of the people tested. Why do you think 10 people in group B reported feeling better? They thought they were getting the new sauce as a result thought that they didn’t have as much gas. (Placebo effect)

Slimotosis What was the initial observation? Slimotosis on Gary’s shell What is the independent variable? Cures (Seaweed and Dr. Kelp) What is the dependent variable? Slime and odor What should Sponge Bob’s conclusion be? Although Gary’s symptoms have disappeared, it is not known which cure was the one that worked. He should redo the experiment and include a control group as well as two other testing groups for each of the proposed cures.