Unit 1 Scientific Method, Theories, & Graphing Data

1.List and describe the steps of the Scientific Method. 2.Explain why we need the Scientific Method. 3.Explain how and why theories change. 4.Analyze the parts of a scientific investigation. (SPI 3221.Inq.2) 5.Interpret graphs that depict real-world phenomena. (SPI 3221.Math.3) 6. Determine why a conclusion is free of bias. (SPI 3221.Inq.6) 7.Evaluate the accuracy and precision of data. (SPI 3221.Inq.4) Objectives

Scientific Method What do you know?!?!

In the beginning… Aristotle (384 BCE-322 BCE or BC) ancient Greek philosopher

Aristotle was so famous that his work influenced thinking in the Western world from his time to the present. This was fine when he was right. But he was so influential that his mistakes were never noticed. Aristotle and his contemporaries believed that all problems could be solved by thinking about them.

Sometimes this worked, other times it did not. For example, Aristotle thought that heavy objects would fall faster than lighter ones.

Now that does seem reasonable at first. And this is how “science” was done in ancient times. But what did Aristotle not do? He never tested his ideas! The world would have to wait almost 2000 years for that to happen.

Galileo Galilei AD or CE Lived in what is today Italy Is considered to be the first true scientist. Why???? Because he actually did the experiment.

Aristotle said that heavy objects fall faster than lighter ones. So Galileo asked, “How much faster?”

So he sent students up to the top of a building and had them drop a heavy ball and a lighter one off at the same time. He had other students waiting below to measure the difference in time between the two hitting the ground.

Today of course we know what happened. Much to everyone’s surprise both balls hit the ground at about the same time! This shows that it is much preferred to test your ideas rather than merely think about them. “One test is worth a thousand expert opinions.” -Bill Nye

Key Idea When conducting an experiment, change one factor and keep everything else exactly the same. The one thing you change is called the variable. All the things you keep the same are called controls.

Galileo’s Experiment What was the variable in Galileo’s experiment? The weight of the balls. What were some controls? Dropped from same height. Dropped at same time. Balls had same shape/size.

Review 1 1.Aristotle 1.Aristotle – smart guy, but didn’t test his hypotheses 2.Galileo 2.Galileo – smarter guy b/c he DID test his hypotheses 3.Variables 3.Variables – change 4.Controls 4.Controls – stay the same

Activity 1 1.In teams of 2, determine the controls and variables of each experiment. Remember, some aspects are obvious while you will have to assume or dig deeper into other aspects. Good Luck!!! *Keep this page, as we will be doing more activities on it.*

Activity 1 Experiment 1 Experiment 1: Kayla and Lucas want to know if the temperature of vinegar affects how quickly it reacts when added to baking soda. They place 1.0g of baking soda into 3 beakers each. They add vinegar of varying temperatures (5ºC, 25ºC, and 80ºC). ---Determine the variables and controls.

Activity 1 Experiment 2 Experiment 2: Veronica and Rhett want to know if stirring affects how quickly sugar dissolves in tea. Veronica weighs out 2g of sugar into two beakers each. Rhett adds 100mL of unsweet tea to each beaker. As he is adding the tea, Veronica is stirring one beaker and Rhett leaves the other untouched. ---Determine the variables and controls.

Scientific Method Steps State the problem (in form of a question). Make a hypothesis. Conduct the experiment. Record and analyze data. Make a conclusion. Report findings to others so they can repeat the experiment.

Hypothesis An educated guess a prediction Use “If”, “then” format if thenWe predict that if we drop a ball from a higher height, then it will bounce higher.

Observations Observations: We use our senses to gather information about the world around us. There are two types of observations. –Qualitative – “quality” –Quantitative – “quantity”

Qualitative Usually made with our senses. Color, shape, feel, taste, sound. Olivia is wearing a blue sweater. The lab tabletop is smooth. You describe this picture qualitatively…

Quantitative How many? Will always have a number. Based on exact measurement. The room is 8 meters across. Sarah is 141-cm tall. Tatyana measured 0.78 g of sodium chloride.

Inferences Inference:A logical interpretation of an event that is based on observations and prior knowledge. What does this mean in 6th grade terms? (Break it down for me.)

Making Inferences You are at the counter in the office to sign in late, and you see a student leave Mr. Nolan’s office crying and upset. We could make an inference as to why the student is upset…………… –Could be in trouble (ISS, OSS, Coots!) –Family problems at home (sick, accident) –Student not feeling well –Student has poor grades (failing, retention)

Theory Has a very different meaning in science than in everyday life. “The detective has a theory about who robbed the bank.” This is a guess. notWhen scientists use the word theory it is not used as a guess.

Theory defined An explanation based on many observations during repeated experiments that is valid only if it is consistent with observations, makes predictions that can be tested, and is the simplest explanation. A logical, time tested explanation for events that occur in nature.

So the theory of gravity, theory of electricity, the germ theory of disease, and the theory of evolution are tested, accepted explanations for events that occur in nature. Theories can really never be completely proven, only disproven. When new evidence comes along, we must modify our theory or at times even get rid of it and start over again.

Ptolemy’s [Tah-Lo-Mi] earth centered theory of the solar system is an example of what can happen when new evidence comes along. When Copernicus showed that putting the Sun in the center made it much easier to predict the planets motions, the old earth centered theory was discarded and a new one developed.

Review 2 1.Scientific Method 1.Scientific Method: Question, Hypothesis, Experiment, Record/Analyze Data, Conclusion, Repeat Experiment. 2.Qualitative Quantitative 2.Qualitative – Physical Description; Quantitative – Numerical Description. 3.Inferences 3.Inferences – Logical, educated guess. 4.Theory 4.Theory – Simple explanation based on several observation and repeated experiments. Can be disproved.

Activity 2 1.In the same teams of 2, read the experiment and describe it in terms of the Scientific Method. *** REMEMBER TO INCLUDE THE FOLLOWING *** 1) Question 2) Hypothesis (if-then) 3) Steps of the Experiment 4) Record Data in table/graph 5) Analyze the Data 6) Form a Conclusion (based on your hypothesis 7) Explain how you would change or modify the experiment if you repeat it.

Activity 2 Experiment Experiment: Brandon and Megan planted 4 pea plants in soils with varying pH (4, 6, 8,10). They thought the plant would grow best with pH=8. Everything besides pH of the soils remained the same throughout the experiment. The plant with pH=4 did not grow, pH=6 grew 6cm, pH=8 grew 1cm, and pH=10 did not grow. 1) Question 2) Hypothesis (if-then) 3) Steps of the Experiment 4) Record Data in table/graph 5) Analyze the Data (full sentences) 6) Form a Conclusion (based on their hypothesis 7) Modifications: Explain how you would change or modify the experiment if you repeat it.

Graphing The visual characteristics of a graph make trends in data easy to see. One of the most valuable uses for graphs is to "predict" data that is not measured on the graph.

Graphing Steps Identify the Variables Determine the scale Number and label each axis Plot the points Draw the graph Give your graph a title

Identify the Variables –Independent Variable - (the thing you changed)  Goes on the X axis (horizontal)  Should be on the left side of a data table. –Dependent Variable - (changes with the independent variable)  Goes on the Y axis (vertical)  Should be on the right side of a data table.

Day (x)Temp (y) “Temperature (Y-axis) changes because of the Day (X-axis).”

Scale –Determine a scale, (the numerical value for each square), that best fits the range of each variable. –Spread the graph to use MOST of the available space.

Label Axes You need to tell everyone reading your graph what the graph means. Be sure to include units.

Plotting Plot each data value on the graph with a dot. You can put the data number by the dot, if it does not clutter your graph.

Day (x)Temp (y) Scale? Axes Labeled? Plotted Points?

Drawing –Draw a curve or a line that best fits the data points. –Most graphs of experimental data are not drawn as "connect-the- dots".

Title Your title should clearly tell what the graph is about and be AS SPECIFIC AS POSSIBLE – ASAP! Example: “The Effects of Acid Rain on Blue-Green Algae During Spring and Fall Precipitation Cycles in Midwestern Colorado” If your graph has more than one set of data, provide a "key" to identify the different lines

Interpolation Interpolate: predicting data between two measured points on the graph. (Can be any point between data points…does not have to be the “midpoint”.) Think - Interstate …traveling between states.

Extrapolation Extrapolate: extending the graph, along the same slope, above or below measured data. Use a dotted line. Think – “Adding extra stuff”

What is Bias? What Is Bias? One kind of bias is a strong opinion about something. You can be biased in favor of something or biased against it. In either case, you may have some facts to support your position, but a bias is based more on feelings and opinions than on facts. In some cases, bias results from a person’s past experiences. Examples: 1. The pollution in our river is caused by the big factory upstream. The people who own the factory are only interested in making money. They don’t care about the environment at all. I heard about them from my friend Barry, and he knows what he’s talking about. 2. Every morning, my grandfather’s rooster crows when it is still dark. About five minutes later, the sun comes up. I don’t know how it works, but my grandfather’s rooster is responsible for the sunrise!

What is Bias? What Is Bias? One kind of bias is a strong opinion about something. You can be biased in favor of something or biased against it. In either case, you may have some facts to support your position, but a bias is based more on feelings and opinions than on facts. In some cases, bias results from a person’s past experiences. More Examples: 3. On the Internet, I learned about a place where aliens have secretly landed a spaceship on Earth. They’re going to take over the world, and when they do, they’ll put all of the redheaded people like me in charge. You’d better be nice to me! 4. Our new science textbook will be terrific! I have used other textbooks by the same company, and they are always well-written and accurate. One of the teachers at our school says this is the best textbook she’s ever used.

Accurate & Precise Data Accuracy: how close a measurement is to the correct answer. Precision: how close each measurement is to one another.

Accurate & Precise Data What do you think?

Accurate & Precise Data What do you think?

Review 3 1.Graphing 1.Graphing: Identify variables, scale, number/label axes, plot points, draw line, title. 2.Independent Variable Dependent Variable 2.Independent Variable – you change, on x-axis. Dependent Variable – changes because of the independent, on y-axis. 3.Interpolate Extrapolate 3.Interpolate – adding points to the middle. Extrapolate – extending points past the end. 4.Bias 4.Bias – prejudice, unfair conclusion. 5.Accurate Precision 5.Accurate – correct. Precision – how close to each other

Activity 3 Each person will complete this on his/her own piece of paper, but you may work in the same teams of 2. You will be given data from an experiment. Your FIRST task is to determine what the Independent Variable is and what the Dependent Variable is. Explain why you chose them. Your SECOND task is to design a graph, plot the points, and label all parts of the graph using the data given to you. Your THIRD task is to interpolate and extrapolate 2 points each on your graph. Be sure to show which points are from the data table and which are inter/extrapolated.

Activity 3 Reminder: 1 – Dependent Variable, Independent Variable. Why? 2 – Graph, Plot Points, Label. 3 – Interpolate 2 points, Extrapolate 2 points Experiment: Kierra and Logan want to know how salt affects the freezing point of water/ice. They think since salt is used to melt icy roads, the salt must lower the freezing point of the water. They test their hypothesis by taking the temperature of an ice-water solution compared to an ice-water-salt solution over 2.5 minutes. Here are their results: Time No Salt With Salt 30s6ºC6ºC0ºC0ºC 60s5ºC5ºC-5ºC 90s4ºC4ºC-10ºC 120s3ºC3ºC-15ºC 150s2ºC2ºC-20ºC

Activity 3 Reminder: 1 – Dependent Variable, Independent Variable. Why? 2 – Graph, Plot Points, Label. 3 – Interpolate 2 points, Extrapolate 2 points Dependent Variable: Temperature Independent Variable: Time – or – Salt WHY?!?! Time No Salt With Salt 30s6ºC6ºC0ºC0ºC 60s5ºC5ºC-5ºC 90s4ºC4ºC-10ºC 120s3ºC3ºC-15ºC 150s2ºC2ºC-20ºC

Activity 3 Reminder: 1 – Dependent Variable, Independent Variable. Why? 2 – Graph, Plot Points, Label. 3 – Interpolate 2 points, Extrapolate 2 points Time No Salt With Salt 30s6ºC6ºC0ºC0ºC 60s5ºC5ºC-5ºC 90s4ºC4ºC-10ºC 120s3ºC3ºC-15ºC 150s2ºC2ºC-20ºC

Activity 3

Reminder: 1 – Dependent Variable, Independent Variable. Why? 2 – Graph, Plot Points, Label. 3 – Interpolate 2 points, Extrapolate 2 points Now Interpolate and Extrapolate 1.Draw a line of “Best Fit” for each set. 2.Interpolate: - Pick two points on each line, label. 3. Extrapolate: - Continue your lines out farther. - Pick two points past 150 seconds on that line. Time No Salt With Salt 30s6ºC6ºC0ºC0ºC 60s5ºC5ºC-5ºC 90s4ºC4ºC-10ºC 120s3ºC3ºC-15ºC 150s2ºC2ºC-20ºC

Activity 3

1.List and describe the steps of the Scientific Method. 2.Explain why we need the Scientific Method. 3.Explain how and why theories change. 4.Analyze the parts of a scientific investigation. (SPI 3221.Inq.2) 5.Interpret graphs that depict real-world phenomena. (SPI 3221.Math.3) 6. Determine why a conclusion is free of bias. (SPI 3221.Inq.6) 7.Evaluate the accuracy and precision of data. (SPI 3221.Inq.4) Review of Objectives

1.List and describe the steps of the Scientific Method. 2.Explain why we need the Scientific Method. 3.Explain how and why theories change. 4.Interpret and/or construct a graph that depicts real-world phenomena. 5.Describe an object qualitatively and quantitatively. 6.Determine independent and dependent variables. 6.Determine why a conclusion is biased or free of bias. 7.Evaluate the accuracy and precision of data. 8.Be able to interpolate/extrapolate data. What Can I Expect on the Test?