Nature of Science Notes

Nature of Science  Nature of Science –  Scientific should be reliable and always changing  Science is complex  No step-by-step method will always be the answer to a question  science relies on skills:  making inferences and observations,  asking questions  analyzing data  communicating to others.

Observations and Inferences  Observation – Using your senses or a tool to record an event, characteristic, or behavior  Example:  Inference – a logical conclusion drawn from available evidence and prior knowledge. They often develop from observations.  Example :

Effective Scientific Questioning  Scientific Question –  question based on observations  identifies something you would like to learn more about by experimentation/researching /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  cannot be measured

Processes Used by Scientists  Ask a Question (state the problem)  questions come from 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 detailed 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.

Conducting Experiments  Test the Hypothesis  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 changed or 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 in a normal situation  Experimental Groups (one or more) – variables are tested in these groups

Sample Experiment 3.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: ____________________________________

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