Variables, Hypotheses, & Scientific Method
Variables, Hypotheses, & the Scientific Method COPY
Biology
Inference vs Observation • Observation-an act or instance of viewing or noting a fact or occurrence for some scientific or other special purpose • Inference-a conclusion or opinion that is formed because of known facts or evidence
Scientific Method = DR. HERC • D = Define the Problem – Written as a question – How can I be a great fighter like Rocky!
• R = Research background info – Ate raw eggs – Punched raw meat – Chased a chicken
• H = Hypothesis/Prediction – Always written in “If. . . then” format • IF (I change this…) • THEN (this will happen…) – Dependent variable (become a great fighter)
• E = Experiment – Includes materials and procedure
COPY
– Independent variable (eat raw eggs)
Scientific Method = DR. HERC • R = Results (FIGHT-Loss) – Data and observations from the experiment – Graphs and charts
– Revisit the Problem and Hypothesis – Restate the results (use numbers) – Evaluate the results • What do the results indicate or show? • Identify errors and possibilities for future experimentation • Should have trained to fight not just eat raw eggs
COPY
• C = Conclusion (3 parts)
Three kinds of variables • An independent variable– is changed by the investigator in an experiment
• A dependent variable– might be affected as a result of that change (IV)
• A controlled variable-
COPY
– A factor that is not changed, or that is held constant – If NOT controlled, could cause a change in results – Can be more than one controlled variable
• Use an IF…THEN statement • The IF is for independent, the THEN is for the dependent. • Teachers have noticed that students who don’t get a good night’s rest before a test do worse than those students who do. • IF students receive a good night’s rest before a test, THEN they will do well on tests.
CO PY
Write a Hypothesis
Example • A student wanted to test how the mass of a paper airplane affected the distance it would fly. Paper clips were added before each test flight. As each paper clip was added, the plane was tested to determine how far it would fly.
Example (cont’d) • The independent variable was the mass of the plane (number of paper clips added). • The dependent variable was the distance flown. • A controlled variable in the experiment was the fact that the same plane was used for each trial.
Practice: Variables & Hypothesis
COPY
• A study was done to find if different tire treads affect the braking distance of a car.
Practice: Variables & Hypothesis
COPY
An ecologist performed an experiment to see if the length of daylight had an effect on the time it takes for fish eggs to develop.
Biology
Inference vs Observation • Observation-an act or instance of viewing or noting a fact or occurrence for some scientific or other special purpose • Inference-a conclusion or opinion that is formed because of known facts or evidence
Scientific Method = DR. HERC • D = Define the Problem – Written as a question – How can I be a great fighter like Rocky!
• R = Research background info – Ate raw eggs – Punched raw meat – Chased a chicken
• H = Hypothesis/Prediction – Always written in “If. . . then” format • IF (I change this…) • THEN (this will happen…) – Dependent variable (become a great fighter)
• E = Experiment – Includes materials and procedure
COPY
– Independent variable (eat raw eggs)
Scientific Method = DR. HERC • R = Results (FIGHT-Loss) – Data and observations from the experiment – Graphs and charts
– Revisit the Problem and Hypothesis – Restate the results (use numbers) – Evaluate the results • What do the results indicate or show? • Identify errors and possibilities for future experimentation • Should have trained to fight not just eat raw eggs
COPY
• C = Conclusion (3 parts)
Three kinds of variables • An independent variable– is changed by the investigator in an experiment
• A dependent variable– might be affected as a result of that change (IV)
• A controlled variable-
COPY
– A factor that is not changed, or that is held constant – If NOT controlled, could cause a change in results – Can be more than one controlled variable
• Use an IF…THEN statement • The IF is for independent, the THEN is for the dependent. • Teachers have noticed that students who don’t get a good night’s rest before a test do worse than those students who do. • IF students receive a good night’s rest before a test, THEN they will do well on tests.
CO PY
Write a Hypothesis
Example • A student wanted to test how the mass of a paper airplane affected the distance it would fly. Paper clips were added before each test flight. As each paper clip was added, the plane was tested to determine how far it would fly.
Example (cont’d) • The independent variable was the mass of the plane (number of paper clips added). • The dependent variable was the distance flown. • A controlled variable in the experiment was the fact that the same plane was used for each trial.
Practice: Variables & Hypothesis
COPY
• A study was done to find if different tire treads affect the braking distance of a car.
Practice: Variables & Hypothesis
COPY
An ecologist performed an experiment to see if the length of daylight had an effect on the time it takes for fish eggs to develop.
