KWL Topic: _________Scientific Method______________________________ Know What do you already know about the topic? Be specific Want To Know What do you want to know about the topic? Learned What have you learned about the topic?

Scientific Inquiry Related to Ch 1

Objectives Apply the scientific method to planning and developing laboratory exercises. Demonstrate lab safety through proper use of laboratory equipment and identify misuse of equipment. Formulate a testable hypothesis using statements such as “If, then, and because.” Make observations of biological processes. Identify relevant variables (Independent, Dependent, Controlled) and explain how to manipulate them. Collect, organize, analyze, predict, infer, evaluate reliability and validity of data. Communicate scientific concepts effectively as a team. Relate scientific principles to everyday life. Interpret and use models and diagrams. Generate questions for further research. Reflect upon the scientific process and outcomes.

What is science? Are you more logical or more creative? On a 1-5 scale, rate how logical you think your thinking is. Now rate how creative your thinking is. Science demands the use of both as we try to make sense of the world around! Prime Example http://www.uweb.ucsb.edu/~feliciano/Bill%20Nye.jpg

Definitions Logic- A way of thinking that uses reasoning to make sense of the world around us. Creativity- A process that involves the generation of new ideas or concepts.

☺The goal of science is to; investigate and understand the natural world, explain events in the natural world, and use those explanations to make useful predictions.

Thinking like a Scientist: observation – process of gathering information (or the info itself) about events or processes in a careful, orderly way data – the information gathered from careful observation 1. quantitative data – obtained by counting or measuring 2. qualitative data – descriptions and characteristics that don’t involve counting inference – logical interpretation of data based on prior knowledge & experience

Explaining and Interpreting Evidence: hypothesis – proposed scientific explanation for a set of observations Often stated in an “If…then…because…” format “If” - (give the conditions including the levels of the manipulated/independent variable) “then” - (state what you predict the responding or dependent variable will do – ↑, ↓, or remain the same) “because” - briefly give the scientific basis for that prediction Use the controversy surrounding the spread of HIV/AIDS in the beginning – competing hypotheses for the spread of the disease and the implications for each on school life! Then Ebola, West Nile, Lyme Ds, what will be next?

Variables and Groups: independent (manipulated) variable - the variable that is deliberately changed, the treatment dependent (responding) variable - the variable that is measured, the response experimental group – the group with the altered level of the independent variable or treatment control group – the group where the level of the independent variable (the treatment) is “normal” or zero, the standard group

Set up a Controlled Experiment: ☺Whenever possible, a hypothesis should be tested by an experiment in which only one variable (treatment) is changed at a time. All other variables should be kept unchanged or controlled. This is known as a controlled experiment.

BrainPOP

1-2 How Scientists Work When have you seen maggots? For thousands of years, people have noticed maggots on rotting things and debated why they appeared spontaneous generation – belief that life could arise from non-living matter Ex: rats come from an abandoned pile of rags http://actionsportsgroup.net/blog/snow/uploads/maggots.jpg

Designing an Experiment State the Problem Form a Hypothesis Analyze Results Set Up a Controlled Experiment Draw a Conclusion Publish Results Record Results

Redi’s Famous Experiment OBSERVATIONS: Flies land on meat that is left uncovered. A few days later, maggots appear on the meat. HYPOTHESIS: Flies produce maggots. Redi was an Italian physician

Independent (manipulated) Variable: gauze covering that keeps flies away from meat Dependent (responding) Variable: whether maggots appear Controlled Variables: - jars - type of meat - location - temperature - time Is there a control group?

Maggots form only when flies come in contact with meat Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur. CONCLUSION:

Recording and Analyzing Data: Written records of data in lab notebooks (now on laptops) 1. Organized into data tables then 2. Transformed into graphs (figures) to see trends & relationships (see pg 25) Water Released and Absorbed by Tree

Drawing Conclusions: Does the data support the hypothesis? Explain how the data does or doesn’t – be specific, like a lawyer in court! Suggestions for improvement – if the experiment was done over, what would make it a better or fairer test? Suggestions for further research – might a different factor be better to investigate, or do your results raise other questions? The answer to the last question is always, “Yes!”

Repeating Investigations: or Do you want to take a new drug that’s only been tested once on one person? Credit – see last slide Are the results repeatable? Are the same results always achieved? If not, was the procedure clear? reliability – consistency of a set of measurements (or the measuring instrument) Common Problems – errors & inconsistencies in reading the instrument, sample size too small, too few readings taken validity – how well did the experimental method actually measure what it was supposed to measure? reliability is precision, while validity is accuracy.

Scientific Theories: ☺In science, the word theory applies to a well-tested explanation that unifies a broad range of observations. Theories must have evidence to back them up. well-tested hypotheses → theory well-tested theory may → law

http://upload. wikimedia http://upload.wikimedia.org/wikipedia/commons/b/ba/Zero_Gravity_Corporation_2.jpg

Characteristics of a Good Experiment Can be repeated by anyone & get the same results Large sample size/many test subjects Performed over long periods of time Tests only one (independent) variable Peer-reviewed – examined by several scientists to determine accuracy Does NOT have to agree with hypothesis – a scientist’s prediction is allowed to be incorrect – and often is Is objective – fair & unbiased, fact (observations) & opinion (inferences) are clearly separated

Related Vocabulary Science Observation Inference Hypothesis theory Independent variable (manipulated) Dependent variable (responding) Controlled variables Data Control group Experimental group Bias Sample size Spontaneous generation Controlled experiment