Science Literacy PDF

Science Literacy Scientific Method Ask Questions Do Report Backgroun...

Science Literacy Scientific Method Ask Questions Do Report Background Results Research Hypothesis is Supported or Construct Hypothesis is Hypothesis False Analyze Design and Results + Conduct an Draw Experiment Conclusions 1-2 Experimental Design Good experimental design is essential for proper scientific method Large # of samples Reduce role of change in determining results Prevent bias Randomization Observers should be blinded to experiment when measuring results Standardize variables Ideally the experiment + control groups differ by only one factor (independent variable) Measure the dependent variable Replication Repeat the test conditions (experiment) on more than one subject Experimental Design Good experimental design is essential for proper scientific method How to determine if 2 variables are related? Large # of samples ReduceIndependent Variable results role of change in determining Prevent bias The variable you manipulate (change) Randomization Dependent Observers Variable should be blinded to experiment when measuring results Standardize variables The variable you measure Ideally the experiment + control groups differ by only one factor (independent Standardized (constant) Variables variable) Measure the dependent variable Anything other variable that may affect Replication the results must be kept the same Repeat the test conditions (experiment) on more than one subject Experimental Design Ask Questions: Could plants benefit from the increase in CO2 in the atmosphere? Background: Not all plants use CO2 for photosynthesis in the same way C3 plants are less efficient at photosynthesis when there is more O2 than CO2 C4 plants overcome low CO2 levels by storing it in their tissues before using it in photosynthesis Experimental Design Do you have reliable results? How do you know the difference between the test groups are the result of the independent variable (CO2) not chance? 1. Repetition Repeat the experiment many times to see if there is the same trend each time. Can someone else repeat the experiment and get similar results? 2. Sample Size (N) Use a large sample size, greater than 30. The more, the better. 3. Standardize Variables Keep all variables (other than the independent variable) the same Experimental Design Do you have reliable results? Do you have reliable results? How do you know the difference between the test groups are the result of the Youvariable independent can only be 100% (medicine) certain if you measure not chance? every possible individual in the system. 1. Repetition Repeat the experiment many times to see if there is the same trend each time. Obviously that is not possible. Can someone else repeat the experiment and get similar results? So we take samples (ie, the plants you decide to grow in 2. Sample Size (N)experiment, or the people in a medical study) your Use a large sample size, greater than 30. But The more, theone sample cannot represent the whole system. better. 3. Use all theSo there is always a chance that the results are due to dtaa another factor……. 4. Standardize Variables Keep all variables (other than the independent variable) the same Experimental Design What conclusions can you make about your hypothesis? After experimental or observational data is gathered, it is analyzed If the data are consistent with the hypothesis, the hypothesis is supported If the data are not consistent with the hypothesis, the hypothesis is proven wrong (null hypothesis) A hypothesis is never proven correct – there might always be other explanations for the data that you havenʼt considered Experimental Design Testing supports What conclusions can youamake hypothesis about not yourby proving hypothesis ? it correct but by not eliminating it through falsification After experimental or observational data is gathered, it is analyzed A hypothesis gains credibility through If the data are consistent with the prediction, the hypothesis is supportedmultiple testing dataCannot If the prove with are not consistent a hypothesis the prediction,because cannot the hypothesis is proven wrong exhaust all alternative hypotheses A hypothesis is never proven correct – there might always be other explanations for the data that you havenʼt considered Repetition in data Scientific Theory A scientific theory Much broader in scope than a hypothesis Usually general enough to generate many new, specific hypotheses, which can then be tested Supported by a large and usually growing body of empirical evidence Widely accepted theories explain a great diversity of observations + are supported by lots of evidence A scientific theory is never proven It becomes stronger as evidence accumulates or it is eventually rejected Global Climate Change The increase of GHG due to human activity as the cause of climate change is a scientific theory (IPCC Assessment Report 2014) Q: Can this theory be proven correct? Science + Technology Science + technology are interdependent Scientific discoveries lead to development of new technologies New technologies benefit scientists But basic goals differ Science aims to understand nature Technology applies scientific knowledge for a specific purpose Science identifies problems, provides insight for solutions Solutions determined by politics, economic, cultural value as well as science + technology 1-13 Science Science is a social activity Most scientists working in teams Scientists share information – publications, seminars, meetings, internet Science seeks natural causes for natural phenomena Limited to the study of structures and processes that we can directly observe and measure Scientific method is necessarily repetitive Scientific literacy is necessary Learning Objectives By the end of the lecture, you should be able to: Appreciate how a scientist asks questions, thinks, and seeks answers. Recognize sound scientific research vs poor scientific design Recognized the different scientific processes to learning facts - Hypothesis based testing, Discovery Science Design an experiment using the appropriate variables and control groups. Recognize the strengths + limitations of a scientific theory, give an example. Understand the role of collaboration in science Recognize how science and technology are related. Recognize how science and politics/economics are related