Nature of Science Notes

1. Nature of Science Notes Name: ______________________________________ Date: ______________________ Period: _______

2. What is the nature of science? • Nature of Science – • Scientific knowledge is both reliable and always developing • Science is so complex that a single step-by-step method may not always be the best way to answer a question, however, all science relies on skills such as making inferences and observations, asking questions, analyzing data, and communicating to others. • Science, by definition, is limited to learning about the natural world we live in. • Contributions to science can be made and have been made by people all over the world

3. Observations and Inferences • Observation – Using your senses or an instrument to note or record an event, characteristic, or behavior • Example of observation: ________________________________________ ____________________________________________________________ • Inference – a logical conclusion drawn from available evidence and prior knowledge. They are often made from observations. • Example of inference: __________________________________________ ____________________________________________________________

4. Effective Scientific Questioning • Scientific Question – A question based on observations that identifies something you would like to learn more about through experimentation/research/survey. • Good scientific questions will: • Be testable through experimentation, survey or research • Be based on observations • Deal with the natural world • Be genuine, something we don’t already know the answer to • It is NOT a scientific question if it: • Includes personal bias and opinion • Has to deal with morals and values • Deals with the supernatural • Relates to phenomena that cannot be measured

5. Processes Used by Scientists • Ask a Question (state the problem) • Good questions come from careful observations • Example: When dropped from a height of 5 meters, will buttered toast land butter-side up or butter-side down more often? • Form a Hypothesis • Hypothesis – A clear statement of what you expect the answer to your question to be • “Educated Guess”, prediction • Example: If dropped from a height of 5 meters, toast will land buttered side down 75% of the time.

6. Conducting Experiments Key Elements of Conducting Experiments: • Scientists conduct experiments, make observations, and take surveys • Controlled Experiment – tests only one factor (variable) at a time • Variables: • Independent Variable – the factor that you change/manipulate • Dependent Variable – the factor that is being observed • Controlled Variables – the factors that remain the same/are NOT manipulated • When testing the hypothesis, these are several things to consider: • Control Group (one) – nothing is tested; this acts as a baseline, i.e. what would happen a normal situation • Experimental Groups (one or more) – variables are tested in these groups

7. Sample Experiment • Test the Hypothesis – Example of a Test • Experimental Scenario: Ms. Freeman and Ms. Dowd wanted to determine if there was a correlation between eating a nutritionally balanced breakfast and success on tests. One group of students was given a healthy breakfast and another group ate their normal breakfast before a test. They found that 7 out of 10 students who ate the healthy breakfast scored 80% or better on tests while 5 out of 10 students who ate their regular breakfast scored 80% or better on tests. • Identify the following from the above experimental scenario: • Independent Variable: ___________________________________ • Dependent Variable: ____________________________________ • Controlled Variables: ____________________________________ • Control Group: ________________________________________ • Experimental Group: ____________________________________ Type of breakfast the students eat Test scores Same amount of sleep, studying, test, etc. Students who eat their normal breakfasts Students who eat the healthy breakfast

8. More Processes Used by Scientists • Analyze the Results • This is completed after all data from experiments has been collected • Tables and graphs are usually used in this step • Draw Conclusions • Do your results support your hypothesis? • Answer is YES repeat experiments or observations to verify results • Answer is NO  check for errors; formulate a new hypothesis • Communicate Results • Communicate results through written or oral report

9. Measurement • Measuring is used in almost all scientific experiments • Measuring can “make” or “break” the experiment • Measuring requires accuracy and precision • Accuracy – The correctness of measurements; is it right? • If measurements are not correct the experiment could have error • If measurements are not correct the data analysis could be wrong • Precision – Getting the same measurement repeatedly; exactness of measurement • SI (System International) Units are used: • The metric system: • meter (m) is used to measure length • liter (L) is used to measure volume • gram (g) is used to measure mass • celsius (oC) is used to measure temperature

10. Metric Prefixes and Conversions • The metric system is based on units of ten • Meter, liter, and gram are the units of 1 • One of these units must ALWAYS be indicated with the abbreviation • Prefixes can be added to indicate greater or lesser • Metric Prefixes: • To convert, simply move the decimal place the same number of spaces to the left or right that you move on the chart • Convert 12.3 m  _____________ mm • Convert 0.564 kL _____________ L • Convert 5.0 dkg  _____________ dcg 12300.0 564.0 500.0