Aaron J. Powner, M.Ed.
High School Science Teacher

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SCIENTIFIC AND ENGINEERING PRACTICES

The Basics

1. Notice interesting objects or phenomena

2. Try to understand them

3. Use this information to do something useful

Methods of Scientific Research

Observation and Inquiry

• Perceive an object or phenomenon
• Formulate questions

Literature Review

• Has anyone already studied this object or phenomenon?
• Review all existing knowledge related to the questions

Hypothesis and Prediction

• Based on observations and literature review, propose an answer to the question
• Predict what will happen if the hypothesis is tested using an "If..., then..." statement.

Experimental Design

• A good experiment will test important variables of the prediction one at a time
• Independent Variable (aka Manipulated Variable) - the condition that is changed on purpose to see what happens
• Dependent Variable (aka Responding Vairable) - the measurment of what happens as a result of the changed independent variable
• Control - the version of the test in which the independent variable is not changed - natural conditions
• Trials - repetitions of each version of an experiment to gather large pools of data
• Data Table - a method for recording data in an organized way

Infer Meaning

• Analysis of the data to determine what the results mean
• Quantitative Data - measurements that produce numeric data
• Qualitative Data - observations recorded during the experiment (non-numeric)
• Statistical Analysis - graphing data to find patterns, finding mean/media/mode of data, calculating standard deviation and percent error (degree of certainty)

Draw Conclusions

• State whether the data supports or refutes the hypothesis
• Use logical arguments
• Identify potential sources of error

Reporting Findings

• Formal article to communicate findings/discoveries
• Elements of formal report include:
  • Anstract
  • Introduction
  • Materials and Methods
  • Results
  • Discussion
  • Acknowledgments
  • References
• Guide to Writing Science Journal Articles
• Example Professional Sciene Journal Article

Peer Review

• Other scientists in similar fields of research are invited to read the journal article before it is published
• Once published, science research facilities commision groups of researchers to repeat imporant experiments to verify the published findings
• These peers often communicate critiques of experimental design, further questions about the hypothesis, and suggest topics for further research

Processes of Engineering

Define and Delimit a Problem

• What is the design for?
• What are the criteria and constraints of a successful solution?

Develop Possible Solutions

• Brain Storming
• Specifying solutions that meet the criteria and constraints
• Model and test solutions

Optimize Solutions

• Compare and improve solutions
• Select "best fit" solution
• Modification of criteria and constraints as needed

Cumulative Nature of Science and Engineering

Every discovery leads to more questions or problems

Every great scientist builds new knowledge upon the foundation laid by countless other scientists

Every scientific discovery is either an addition to or a correction of old knowledge

Scientific Publications and Journals