Scientific Thinking Topic 1 Day 3

Today you will… Evaluate the merits of scientific explanations produced by others. Identify examples of scientific inferences made from observations.

Benchmarks SC.912.N.1.1 Define a problem based on a specific body of knowledge. SC.912.N.1.6 Describe how scientific inferences are drawn from scientific observations, and provide examples from the content being studied.

Essential Question How has the scientific method contributed to the development of modern science?

Scientific Method Observation – Use five senses to gather information Problem Statement – Observations lead to a question you’d like to answer Research – Look up background information/prior knowledge Hypothesis – A prediction of what you think is going to happen Experiment/Procedures – Testing of the hypothesis Data/Results – Recording the results of the experiment Analysis (Interpretation) – Explanation of results collected Conclusion – Summary of the experiment and stating whether or not hypothesis was supported Communication – Publication of the experiment and results Students will rotate through the following stations using the student guide completing each of the listed activities.   Teacher should set up two of each of the following stations keeping group size between 2-3 students. Students should complete each station in no more than 10 minutes then move on to the next available station. Observe Hypothesis Measure Infer/Predict Interpret and Communicate

THINK-WRITE-PAIR-SHARE Write some observations from this picture. Based on those observations write one logical explanation for what happened. Encourage students to share their “observations.” At this point clarify that an observation can only be made with their senses. You may have a student say that someone died or was shot, but that is not an observation, it is an inference they are making on prior knowledge and experience.

Observations vs. Inferences Good science investigations and projects begin with detailed observations. These observations, plus your natural curiosity, lead to effective problem statements. What are some observations you can make about the picture above? What are some inferences you can make about your observations? Discuss with students that observation is the act of using the 5 senses to collect information while inference is the use of logic to make conclusions from observed data. Remind students that observation can be quantitative or qualitative, e.g., number of girls and boys, the color of their uniform shirts, etc. Example of inferences could be: this schools has more boys than girls; there is only 1 color shirt allowed, etc.

Control and Variables Constants – All the factors that remain the same throughout experiment. Independent (manipulated) – Only ONE factor being tested. (Test and Trials) Dependent (responding) – The part of the experiment that responds to the change. The outcome of experiment. Control – Part of the experiment that does NOT include the Independent Variable (except in living things) and is used for comparison.

DRY MIX DRY – Dependent/Responding Variable on the Y-axis MIX – Manipulated/Independent Variable on the X-axis MIX

Graphing 101 Title: MV vs RV Label (units) Label (units) Use graphing paper. Must be large, at least half the page Graph parts Must have a Title Axis: X & Y must have Labels and units. Plot the data correctly and connect the points (Don’t extend beyond the points) If a legend is needed include it somewhere within the graph Axis must be in equal increments Choice of type of graph Line graphs are used to track changes over time, length, volume, concentration, etc. Bar graphs are used to compare groups of things or large changes of time Label (units) Label (units)

Quantitative vs Qualitative Qualitative = Quality (descriptions) Quantitative = Quantity (amounts)

Relationships between Variables Directly Proportional: If the relationship is direct, then as your x value increases, your y value increases. On a graph, this would be a positive slope and the graph would increase from left to right. Inversely Proportional: If the relationship is inverse, then as your x value increases, your y value decreases. Trend: Upward trend: there has been a steady/sudden/dramatic increase. Downward trend: there has been a steady.....decrease. Stable: the graph displays a stable growth pattern.

Hypothesis and Theory Hypothesis Theory Definition A hypothesis (plural hypotheses) is a proposed explanation for a phenomenon. Scientists generally base scientific hypotheses on previous observations that cannot satisfactorily be explained with the available scientific theories. In science, a theory is a well-substantiated, unifying explanation for a set of verified, proven hypotheses. Based on Suggestion, possibility, projection or prediction, but the result is uncertain. Certainty, evidence, verification, repeated testing. Testable Yes Falsifiable Is well substantiated No (revisable with new evidence) Yes (revisable with new evidence) Data Usually based on very limited data Based on a very wide set of data tested under various circumstances. Instance Specific: Hypothesis is usually based on a very specific observation and is limited to that instance. General: A theory is the establishment of a general principle through multiple tests and experiments, and this principle may apply to various specific instances.

Theory vs Law SIMILARITIES BOTH are well-supported by the result of many different experiments. BOTH are widely accepted by the vast majority of people in that field. BOTH help unify a field. Both can be changed if new observations or evidence do not fall within the theory or law. A Law is a well-supported description of WHAT is happening (a set of observations) A Theory is a well- supported explanation of HOW it happens.

Title for a graph: M.V. (I.V.) vs R.V. (D.V.) Hypothesis: Increases or Decreases Increases Or Decreases If M.V. (I.V.) then R.V. (D.V.) Because Relationship between the variables: The relationship between the variables is Therefore, as the M.V. (I.V.) , the R.V. (D.V.) Directly proportional or Inversely proportional Increases or Decreases Increases Stays constant Decreases

SCIENTIFIC METHOD STATIONS

Seed Germination Lab It’s not easy to tell if a seed is “dead.” Only if it fails to germinate when provided the proper conditions and any dormancy mechanisms are broken can we consider a seed “dead.” Seed companies typically test the germination of seeds before sale. The results of these tests, the germination percentage, are typically provided on a seed packet. The radish (Raphanus sativus) is an edible root vegetable of the Brassicaceae family that was domesticated in Europe in pre-Roman times. They are grown and consumed throughout the world. Radishes have numerous varieties, varying in size, color and duration of required cultivation time. There are some radishes that are grown for their seeds; oilseed radishes are grown, as the name implies, for oil production. Radish can sprout from seed to small plant in as little as 3 days.

Now It’s Your Turn Pre-Lab: Set Up Seed Germination Write the Following parts of your lab report in class Title Problem Statement Introduction Hypothesis Materials Procedures Variables Finish for HW. MUST BE COMPLETED in order to do lab next class. It must be HANDWRITTEN!

PROBLEM STATEMENTS Water Does the amount of water affect seed germination? Does different concentrations of salt water affect seed germination? Does changing the temperature of the water affect seed germination? Light Does the amount of light affect seed germination? Air Does the amount of air affect seed germination? Soil Does the amount of soil affect seed germination? Seed How does the number of seeds affect germination rates? pH How does pH affect seed germination?

Exit Ticket Which of these inferences is BEST supported by observations of this animal? The animal spends much of its time digging. This animal usually hunts for food at night. This animal is herbivorous. This animal has poor hearing. If a student needs to do research on heredity for a science project, which of these sources is the most reliable resource A weekly magazine. A newspaper tabloid. A national newspaper. A professional journal. 3. Hypothesis: If pine seeds are exposed to a forest fire, then there is an increase in their germination rate because their coat is thinner and quicker to germinate. Based on the hypothesis above, the most valid and reliable test of this hypothesis would include an experimental group of pine seeds that was recovered from a fire area and pine seeds that were germinated after a fire. tolerant of fire. found before a fire. placed in a fire.