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BIOLOGY NOTES SCIENTIFIC METHODS PART 2 PAGES 13-18
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Standards: _____ Describe how scientific inferences are drawn from scientific observations and provide examples from the content being studied ____ Define a problem based on a specific body of knowledge and: pose a question about the natural world; plan an investigation; conduct systematic observations; infer the meaning of data collected to answer the question; communicate the data and explanations to others 1.2 1.3
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____ Recognize that theories do not become laws, nor do laws become theories; theories are well supported explanations and laws are well supported descriptions 1.6
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Essential Questions: 1. 2. What inferences can we make about living
things from our observations? How can we tell science from non-science?
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I. The Goal of Science The goal of science is to ___________ and ___________ nature How is this goal accomplished? By using the _________ ________ Scientific Method = the use of certain processes to find ________ to questions about the world investigate understand scientific method answers
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it is an _________ process
it provides us with a way of knowing ____ and _____ things occur in nature it does NOT answer questions about __________________, ______, or morals It is considered science only if it is __________, _____________, ________, ____________, ________ and _________ on-going how why aesthetics (beauty) ethics consistent observable natural predictable testable tentative
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e.g. There are no scientific methods to discover if:
Is abortion right or wrong? Is the Mona Lisa beautiful?
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II. Steps of the Scientific Method
1. Asking questions about ______ Usually, a scientists seeks answers to topics that are __________ to him or her e.g. nature interesting Which bat is the best? What are the healthiest foods for an athlete? “Lorenzo’s Oil”
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2. Make observations about the _____ through _________ or ___________
Observations = information that is gathered using the five ________ topic research experience senses
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2 Types of observations:
a. quantitative observations = observations in ___________ form e.g. b. qualitative observations = observations that are ____________ and do not involve __________ numerical counting, temperature, mass, density, volume, pH, area, etc. descriptive numbers behavior, appearance, voice recordings, tape recordings, etc.
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3. Form a scientific ________
A scientific question differs from a general _________ because it is very ________ observations and _________ allow a scientist to narrow his _______ so that the outcome answers a very precise question e.g. A good scientific question would be: A bad scientific question would be: question question specific research search What is the effect of lysol on radish seeds? What is the effect of household cleaners on plants?
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4. Form a __________ observations and research on a specific scientific question lead scientists to make __________ inference = a logical explanation using _____ knowledge, research or ___________ hypothesis inferences prior experience
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e.g. You are interested in the subject of Daphnia, or water fleas, and their heart rates. You know caffeine speeds up human heart rates through experience and research. You have already formed the following scientific question: What is the effect of caffeine on the heart rates of Daphnia? What is a reasonable inference based on your observations and research of your topic? caffeine speeds up Daphnia heart rates
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hypothesis = a tentative, ________ explanation for a question or problem.
What is the difference between a hypothesis and an inference? ________________________ a hypothesis is not just a random ______ to make a hypothesis testable apply ___ and _____ statements e.g. How could you turn your inference above into a hypothesis? testable an inference is not testable guess if then If caffeine is given to Daphnia, then their heart rate will increase .
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5. Design an experiment Experiment = a __________ that tests a ___________ by the process of collecting information under __________ conditions. light, temperature, _____, equipment used, type of material and use of _________ are all different conditions or variables that could be considered in any ___________ the goal of an experiment is to know that only __ variable effects the _________ procedure hypothesis controlled time materials experiment 1 outcome
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controlled experiments test a hypothesis by changing only __ condition or ________ at a time
2 types of variables in controlled experiments: independent variable = the variable that is ________ in the experiment; also known as the ___________ variable b. dependent variable = the variable that is being _________ in the experiment; also known as the __________ variable 1 variable changed manipulated measured responding
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e.g. It is hypothesized that if roses are given more water than normal, then they will grow taller than normal. To test this, a student grew 3 identical types of roses. One with a normal amount of water, one with twice as much water and one with three times the recommended amount of water. They were given the same amount of sunlight, plant food and type of water.
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1. What is the independent variable. 2. What is the dependent variable
1. What is the independent variable? 2. What is the dependent variable? 3. Why were all other variables kept the same? amount of water rose growth to know that only water effects the outcome
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in any experiment in which a scientists changes how something naturally occurs, he or she must also have a control ______ to serve as a basis of ___________ control groups allow a scientists to compare their outcome to what is ________ seen e.g. In the example above, was there a control group? If so, why? group comparison normally yes because without a control group it would not be known if any of the roses grew more than normal
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6. Collect Results Results, often called the _____, can be collected in a variety of ways e.g. Some results will be collected in a __________ under controlled conditions. Other results cannot be collected in a lab. These types of experiments are called _____ _______. data notes, recordings, pictures, timing measurements laboratory field studies migratory paths of birds
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A good scientist will have results that include both ____________ and __________ observations
Results from an experiment that are ___________ can be represented easily using a ______ the independent variable would be on the __________ axis (also called the ___ axis) while the dependent variable would be placed on the _______ axis (also called the ___ axis). quantitative qualitative quantitative graph horizontal X vertical Y
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e.g. Using the chart below to graph the results:
ROSE PLANT AMOUNT WATER AMOUNT GROWTH mL cm mL cm mL cm
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7. Draw a conclusion Conclusion = a logical ___________ that summarizes the results or evidences and either _________ or denies the hypothesis. e.g. What was the conclusion of the rose experiment? explanation supports more water = more growth
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A good scientist will repeat their experiments many times so that their experiment can be considered _____ e.g. Data and conclusions that are proven ______ because of repeated trials are often published in scientific ________ so that other scientists can test them. valid new medicines valid journals
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III. Theories vs. Laws If a particular hypothesis is supported by a large body of evidence, over time, from many different _____________ conducted by multiple scientists then it can become a ______ Theory = an explanation of natural phenomenon that is __________ by a large body of scientific evidence from many different _____________ and ____________; explanation of _____ things occur in nature e.g. investigations theory supported investigations observations why theory of evolution, big bang theory cell theory
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theories DO NOT become scientific _____ thus, a theory is generally considered a universal ___________ for some sort of natural phenomena Scientific law = certain __________ of nature; descriptions of _____ things occur in nature e.g. What is the difference between a theory and a law? laws explanation principles how gravity, inertia, laws of thermodynamics theories describe why nature occurs laws describe how nature occurs
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