Chapter 1 How Scientists Work Scientific Method Chapter 1 How Scientists Work

Lecture Outline – The Scientific Method PowerPoint Notes textbook questions Keys

How Scientists Work: Solving the Problems Much of biology deals with solving problems These problems can be environmental, ecological, health related, etc. No matter what types of problems are being studied, scientists use the same problem-solving steps called… The Scientific Method

Scientific Method Definition The scientific method is- A logical and systematic approach or process to problem solving.  An organized way of using evidence to learn about the natural world. http://images.google.com/imgres?imgurl=http://web.syr.edu/~ksegrave/Courses_pages/FieldBiology/FieldBioImages/method.gif&imgrefurl=http://web.syr.edu/~ksegrave/Courses_pages/FieldBiology/Science.html&h=175&w=225&sz=17&hl=en&start=11&um=1&tbnid=wdFWEsauzWqdBM:&tbnh=84&tbnw=108&prev=/images%3Fq%3Dscientific%2Bmethod%26svnum%3D10%26um%3D1%26hl%3Den%26rls%3DGGLB,GGLB:1969-53,GGLB:en%26sa%3DN http://en.wikipedia.org/wiki/Scientific_method

Scientific Method Listing the Steps Make an Observation Define the Problem State the Hypothesis Design an Experiment to test Hypothesis Collect and Record Data Analyze Data Draw Conclusions Report Results If needed, Do more investigation

1. Make Observations As we all know, frogs have four limbs. An observation is recording a description of something unusual in your natural world by using your senses What’s up with these froggies? http://www.science.psu.edu/alert/Images/Kiesecker7_-02images/Deformed_frog_assorted_RASY.jpg

2. Questioning Recognize, state or define the problem Ask scholarly questions: What…? When…? Where…? Who…? Why…? How…? http://images.google.com/imgres?imgurl=http://news.minnesota.publicradio.org/features/2005/10/21_bensonl_research/images/truncfemur_large.jpg&imgrefurl=http://news.minnesota.publicradio.org/features/2005/10/21_bensonl_research/&h=225&w=300&sz=9&hl=en&start=7&um=1&tbnid=lA9c0bTzPYtApM:&tbnh=87&tbnw=116&prev=/images%3Fq%3Dfrog%2Bdeformities%26svnum%3D10%26um%3D1%26hl%3Den%26rls%3DGGLB,GGLB:1969-53,GGLB:en%26sa%3DN http://academic.brooklyn.cuny.edu/geology/leveson/core/graphics/nyc_mins2/qmarks.gif http://www.kidcrosswords.com/animated_dictionary/d_e_f/frog.gif

3. Researching Gather information related to the problem by: Reading, observing , measuring, taking samples, etc. How frogs normally develop from eggs The % of frogs with the deformities Number of other species in the pond with deformities Previous or new pollutants in the pond Change in amount of UV (sunlight) exposure on eggs http://www.okc.cc.ok.us/biologylabs/Images/Scientific_method_images/frog.jpg

4. Hypothesizing A hypothesis is: An educated guess, trial answer, possible solution, prediction Must written as an “If…Then…” statement Must be testable or measurable Is based on your research and previous experience http://info.hartwick.edu/biology/def_frogs/Introduction/Exploration/explore.html#The%20obvious%20question http://www.science.psu.edu/alert/Images/Kiesecker7_-02images/Deformed_frog_assorted_RASY.jpg

5. Experimenting An experiment is a procedure to test your hypothesis Design an experiment that will realistically examine the claim made in the hypothesis http://info.hartwick.edu/biology/def_frogs/Introduction/Exploration/explore.html#The%20obvious%20question http://www.tmbfree.com/images/graphics/clipart/froggy2.gif http://images.google.com/imgres?imgurl=http://www.frogcollecting.com/gallery/A2t.gif&imgrefurl=http://www.frogcollecting.com/gallery/gallery.html&h=97&w=80&sz=1&hl=en&start=8&um=1&tbnid=hR-tjkzZyAWtTM:&tbnh=81&tbnw=67&prev=/images%3Fq%3Danimated%2Bjumping%2Bfrog%26svnum%3D10%26um%3D1%26hl%3Den%26rls%3DGGLB,GGLB:1969-53,GGLB:en%26sa%3DN

Control and Experimental Groups used as a standard of comparison the group containing the factor (variable) that has been changed Control group: Experimental group: (manipulated or independent variable) Two groups of jars Uncovered jars Covered jars

Variables in an Experiment Variables - Factors that can be changed Controlled Variables - all the variables that remain constant Manipulated Variable or Independent Variable - factor in an experiment that a scientist purposely changes or makes different Responding Variable or Dependent Variable - the outcome or results, factor in an experiment that may change because of the manipulated variable…. what a scientist wants to observe or measure

6. Collect and Record Data Information in the form of observations and measurements made in an experiment Types of Recorded Data Quantitative - observations that are numerical Ex: amounts, frequency, measurements Qualitative - observations that are of a descriptive nature Ex: color, smell, texture, taste, sound http://images.google.com/imgres?imgurl=http://www1.istockphoto.com/file_thumbview_approve/310758/2/istockphoto_310758_the_mad_scientist.jpg&imgrefurl=http://www.istockphoto.com/file_closeup/%3Fid%3D310758%26refnum%3D361997%26Lang%3Den&h=367&w=380&sz=49&hl=en&start=27&um=1&tbnid=vejiM3E-VcJ5JM:&tbnh=119&tbnw=123&prev=/images%3Fq%3Dscientist%26start%3D20%26ndsp%3D20%26svnum%3D10%26um%3D1%26hl%3Den%26sa%3DN

Number of Plants in each area Data Data must be grouped neatly and organized into: tables charts Figures graphs A Table has rows and columns to organize data. Number of Plants in each area Plant # Area A B Area C D 1 10 6 25 30 2 5 3

7. Analyze the Data Examine data tables, charts, and graphs Examine experimental notes Look for trends, patterns, and averages Report what your data shows

8. Draw Conclusions A conclusion is a restatement of the hypothesis: Ex: The data from the experiment either supports or rejects the hypothesis. Support your conclusion with specific, numerical data gathered from the experiment

9. Determine Limitations Scientists look for possible flaws in their research They look for faulty (inaccurate) data They look for experimental error or bias's They decide on the validity of their results They make suggestions for improvement or raise new questions

10. Publish Results Communication is an essential part of science Scientists report their results in journals, on the internet, or at conferences This allows their experiments to be evaluated and repeated Scientists can build on previous work of other scientists Redi’s experiment on insects generation

Scientific Theory A theory is an explanation of a set of related observations or events based upon proven hypotheses and verified multiple times by detached groups of researchers http://www.antiquark.com/img/scientific_method.jpg http://wilstar.com/theories.htm

Scientific Law Scientific Method Scientific laws represent the cornerstone of scientific discovery They must be simple, true, universal, and absolute If a law ever did not apply, then all science based upon that law would collapse http://www.debunking911.com/hypothesis.gif http://wilstar.com/theories.htm