Chapter 1  4.1 Scientific Method

For both photos A and B, make 2 observations and one inference. QOD For both photos A and B, make 2 observations and one inference.

Look at these two sets of animal tracks. 1. List 3 OBSERVATIONS 2. Make an INFERENCE

Now what do you think? 3. Make 3 OBSERVATIONS 4. Make an INFERENCE

Now what do you think? 5. Make 3 OBSERVATIONS 6. Make an INFERENCE

Analyze Results and Draw Conclusions : (hypothesis true or false) Chapter 1.4 - The Process of Life A. Scientific Method: The general process of science is said to be characterized by a sequence of stages. (The Scientific Method!) Ask Question Do Research Construct Hypothesis Test with experiment Analyze Results and Draw Conclusions : (hypothesis true or false) Report Results Others test idea

Others test idea

Observation: direct method of recording information Scientists believe nature is orderly and measurable. Science also considers that natural laws do not change with time. Phenomena can therefore be understood from observations. Actual science research may also involve chance                  (e.g., Alexander Fleming’s discovery of penicillin). Quantitative – measureable or countable Qualitative – describable, not measureable -red flowers -smells like fresh baked cookies -Tastes bitter 3 meters long 4 marbles 50 kilograms 35 degrees Celsius

Inference: The process of drawing a conclusion from given evidence. C. Hypothesis 1. A hypothesis is a possible explanation for a natural event - must be testable Inference: The process of drawing a conclusion from given evidence. Examples of hypotheses, check those that are valid and can be tested _____Bluebirds sing to attract mates.  _____ Bluebird songs are beautiful. _____ Only male bluebirds sing.  _____ Sparrows will leave territories where they hear bluebird songs..  _____ Bluebirds hate sparrows.

FALSIFIABILITY - It must be testable! It is important than any statement or hypothesis is falsifiable - if there is no evidence out there that would prove the statement wrong, then there is no point in running any tests. - It must be testable!

It is bad science to ask someone to PROVE A NEGATIVE. For example: Prove that ghosts don’t exist. Prove that cell phones don’t cause cancer. Prove that there are no aliens. Prove that telepathy doesn’t exist. The burden of proof lies on the claimant. If you make a claim, then you must be the one to provide evidence for that claim. (It is not on other people to show it to be false.)

Do spotted frogs live better in dry, damp, or very wet environments? D. Experiments/Further Observations 1. Testing a hypothesis involves either further observations or conducting an experiment. 2. An experimental design is proposed that tests the hypothesis. Scientists may use a model (global warming), but models are not always valid Do spotted frogs live better in dry, damp, or very wet environments?

Do spotted frogs live better in dry, damp, or very wet environments? Experiment: three spotted frogs of similar size and put in three different tanks. The tanks are the same size and shape. The frogs are given the same food. Tank 1: wet environment Tank 2: damp environment Tank 3: dry environment

E. Data 1. observable and objective. 2. often displayed in a graph or table. 3. Often the data must be inspected for the probability the data could show a relationship by chance;                         this is a measure of “significance.” You roll two dice, they both turn up ONEs.  This does not fit your prediction that you will only roll a ONE  1 out of 6 times.  Is the data significant enough to change your prediction?

F. Conclusion 1. Whether the data support or reject the hypothesis is the basis for the “conclusion.” - avoid the word "prove"  2. The conclusion of one experiment can lead to the hypothesis for another experiment. 3. Science findings are reported in scientific journals so results are available to the research community (peer review). 4. The experiments and observations must be repeatable or the research is suspect.

what does it really mean? G. Scientific Theory: well-substantiated explanation of some aspect of the natural world that is acquired through the scientific method, and repeatedly confirmed through observation and experimentation. The ultimate goal is to understand the natural world in scientific theories, and conceptual schemes supported by a broad range of data. Say What?  what does it really mean? 

H. A Controlled Study: in a lab 1. Some investigations are managed where conditions can be kept constant a. A variable is a factor that can cause an observable change     b. The independent or experimental variable is the step that is manipulated or changes (ex. ? ). c. A dependent variable is part of the experiment that changes and is measured. (ex: ? ) Experiment: three spotted frogs of similar size and put in three different tanks. The tanks are the same size and shape. The frogs are given the same food.

Example of a Controlled Study Observation: Babies are born with severe birth defects, mothers of these babies report taking the drug thalidomide during pregnancy for morning sickness. Question: Does thalidomide cause birth defects? Hypothesis: Thalidomide causes birth defects.

Experiment: Control group: Mice not given thalidomide during pregnancy Variable: Mice given thalidomide during pregnancy In this experiment, mice born from both the control and variable group will not have birth defects. This experiment was performed long before thalidomide was marketed and prescribed to pregnant women. Does these mean that the hypothesis is not supported?

A Field Study: observe and collect data in the natural habitat or “real world” 1. Observations led the researcher to the hypothesis that male bluebirds vary their aggressiveness toward other males depending on the time during the cycle of breeding. 2. To test the hypothesis, a male bluebird model was placed by the nest while the male was gone and observations were made upon his return. 3. A control consisted of a model of a robin placed in the same position for some nests. Control

4. Resident male bluebirds did not bother the control model but were aggressive toward the male bluebird model depending on the stage in nesting. 5. The conclusions confirmed the researchers hypothesis and were published in a science journal

Quick Review:  What is a Theory? A Theory is an explanation for natural events that is based on a large number of observations. Can also be referred to as a PRINCIPLE or a LAW. Scientific Theories join together well supported and related hypotheses   Theories must explain a wide range of observations Theories must be falsifiable Theories can be changed if new evidence presents itself Generally, a THEORY explains the phenomenon  (WHY)         a  LAW defines it, or establishes a pattern  (WHAT)

The evolution and creationism theory debate? theory? Keeping in mind that there is nothing wrong with personal or religious beliefs, it is debated if things like evolution and creationism can be scientific theories because they may not meet the criteria of a scientific theory itself. 1. tells us what happened, does it explain how, when, why or through what mechanism? 2. Can either be proven false? - ie, how could you disprove the existence of a divine creation 3. Is it based on natural causes (natural causality)? 4. Can it be tested and proven in varies ways with multiple hypothesis? Can you test history?

Simply put: The simplest explanation is usually the correct one. What is Occam's Razor? Ockham's Razor (Occam is the latinized and more common spelling) is a principle proposed by William Ockahm in the 15th century. The original principle stated "Pluralitas non est ponenda sine neccesitate" which translates as "entities should not be multiplied unnecessarily" Simply put:  The simplest explanation is usually the correct one. 

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