What is Science?? Biology IA Spring 2013

Goals of Science To investigate and understand the natural world To explain events in the natural world Use the explanations to make predictions

Observations and Inferences In your notebook, make two columns like you see below: ObservationsInferences

Carefully examine the details of the picture below and write 3 observations and 3 inferences in the correct column in your notebook.

Observation - gathering information about events using the senses Inference – a logical interpretation based on prior knowledge or experience o Follows an observation

Examine the picture below. Write 3 observations and 3 inferences in your notebook. Label each statement as O (observation) or I (inference). Examine the picture below. Write 3 observations and 3 inferences in your notebook. Label each statement as O (observation) or I (inference).

Designing an Experiment

Scientific Method A series of steps: Observation Ask a Question Research State the Hypothesis Controlled Experiment Record and Analyze Data Draw a Conclusion

It’s what you want to learn Must be specific and testable! Example: Does growing a plant in fertilized soil produce more flowers? Question

Research Find out what is already known about the topic o Example: research plant growth, soil, fertilizer

A proposed answer to the question A statement Must fit observations Must Predict Must be testable Contains If….Then Example: If a planted is in fertilized soil then it will produce more flowers. Hypothesis

Design a Controlled Experiment Only change one variable at a time Independent (Manipulated) variable - the factor that will be changed (ex: type of soil) Dependent (Responding) variable - what is being measured (ex: number of flowers) Controls - all of the factors that will stay the same (ex: plant type, water, light)

Groups in an Experiment Control Group - nothing is changed (normal conditions) o Example: Petunia plants in regular soil Experimental Group - the group containing the variable that has been changed o Example: Petunia plants with fertilizer in soil

Data- information gathered from observations Quantitative – expressed as numbers o Example: There are FIVE flowers on the plants. Qualitative – descriptive characteristics (usually can’t be counted) o Example: The flowers are bright purple. Record and Analyze Results

Draw a Conclusion Explains results of experiment Was the hypothesis supported or not?

Scientists must be able to test one another’s investigations to see if the same results can be reproduced! Repeated results from experiments may lead to a: Theory - a well-tested explanation that is supported by many observations o Develops from evidence after doing many experiments