Chapter.3b Scientific Method Mrs. Baldessari Biology Objective : Identify and apply the steps of the scientific method. of 2
What is the goal of science? The goal of science is to: investigate and understand the natural world. explain events in the natural world. use those explanations to make useful predictions. 2 of 2
Thinking Like a Scientist Scientific thinking begins with observation. Observation is the process of gathering information about events or processes in a careful, orderly way Use your senses to observe See, hear, touch, taste, smell, etc. Can also use tools to measure Temperature, length, volume, etc. 3 of 2
What are the steps of the scientific method?. Define the problem a. Select an event or phenomenon for investigation. b. The problem is often based on some type of unexplainable observation. c. The problem is usually stated as a question to be answered. 4 4 of 2
What are the steps of the scientific method? 2. Gather relevant research a. The researcher gathers useful information from scientific literature. b. Observations of the problem may also contribute to research. 5 5 of 2
What are the steps of the scientific method? 3. Formulate a hypothesis A hypothesis is an educated guess about the answer to the problem. The hypothesis is based on information, which has been learned about the problem through research. May be stated as an If., then statement A hypothesis may be ruled out or confirmed. 6 6 of 2
What are the steps of the scientific method? 4. Test the hypothesis A hypothesis must be proposed in a way that can be tested. Hypotheses are tested by performing controlled experiments or by gathering new data. Remember, controlled experiments are experiments that only have one variable that can change, all other factors are held constant 7 7 of 2
What are the steps of the scientific method? 5. Record data and observations The information gathered from observations is called data. Quantitative data are expressed as numbers, obtained by counting or measuring. Qualitative data are descriptive and involve characteristics that can t easily be measured. 8 8 of 2
Look around the room list Five Quantitative observations:. 2. 3. 4. 5. 9 of 2
Look around the room list Five Qualitative observations:. 2. 3. 4. 5. 0 of 2
Inferences Scientists use data to make inferences. An inference is a logical interpretation based on prior knowledge or experience. Is this an observation or inference?. Sam is smiling because he is happy 2. Sarah s gold colored braces were removed today of 2
Observation vs inference 2 of 2
Designing an Experiment with Twinkies Discussion of independent variables and control variables 3 of 2
What is the control? What is the independent variable? 4 of 2
Control Is an experimental set-up with all the parts of the experiment BUT NOT the one variable being tested 5 of 2
What is the independent variable? What might a control be? 6 of 2
What is the independent variable? What might a control be? 7 of 2
Identify Variable and the control: 8 of 2 8
To get all the air out, the twinkie was liquified. So which side is the control? 9 of 2
What are the steps of the scientific 6. Draw conclusions method? Researchers often work in teams to analyze, review, and critique each other s data and hypotheses. A review process helps ensure conclusions are valid. To be valid, a conclusion must be based on logical interpretation of reliable data. Always address sources of error are your results legitimate? Theories and laws are heavily supported by experimental results 20 of 2 20
Figure.: The various parts of the scientific method. Copyright by McDougal Littell. All rights reserved. 2 2 of 2
Science is an ongoing process that involves: asking questions observing making inferences testing hypotheses 22 of 2
State the Question What is the effect of 23 of 2 23
Hypothesis If then If I diligently wear my goggles in the lab, then I will not injure my eyes during Chemistry class this year. 24 of 2
Experiment Independent Variable -what you change goes on the X-axis of the graph Dependent Variable -what changes as a result of what you did goes on the Y-axis of the graph 25 of 2
Independent Variable? Dependent Variable? 26 of 2
Experiment Constants-all the things in the experiment that stay the same In a Twinkie lab : same brand of Twinkies same flavor of Twinkies same degree of freshness 27 of 2
Experiment Control the part of the experiment that does not have the independent variable in it In a Twinkie lab, it could be the room temperature 28 of 2 28
Experiment Record the data graphs charts video write observations measurements 29 of 2 29
Conclusion Agree or disagree with the hypothesis Goggles did protect my eyes during an accident 30 of 2 30
Scientific method State your question or the problem Do background Research Formulate a hypothesis, identify variables Design a Controlled Experiment, establish a procedure Record Results Analyze Results Draw a conclusion Present results 3 of 2
Science as a Way of Knowing Scientific understanding is always changing. Good scientists are skeptics who question both existing ideas and new hypotheses. 32 of 2
Observations involving numbers are known as a. qualitative observations. b. hypothetical observations. c. quantitative observations. d. inferred observations. 33 of 2
A scientist takes paint chips from 0 apartments in a large building. She tests for the presence of lead in the paint and finds it in all 0 samples. She then concludes that lead paint is probably present in all 20 apartments in the building. This conclusion is an example of a. a scientific fact. b. a scientific error. c. proof. d. a reasonable inference. 34 of 2
A possible explanation for a set of observations is known as a. data. b. a hypothesis. c. an inference. d. a result. 35 of 2
A good scientific hypothesis must be a. correct. b. able to be tested. c. obvious. d. based on common sense. 36 of 2