Improving scientific thinking and experimental design skills in undergraduate studentsAngela Hodgson, North Dakota State UniversityFiona Rawle, University of Toronto at Mississauga.
How did this collaboration start? • Talked at BLC • Emailed each other after BLC • Applied for and received catalytic grant THANK YOU Jane Reece, the family of Neil Campbell, and Pearson for your support!
Rationale – Science Process Skills • What are science process skills? • Experimental Design • Graphing and visualizing data • Statistical analysis and hypothesis testing • Scientific communication • Why are science process skills important?
Learning Outcomes UTM intervention NDSU Intervention • Explain what a hypothesis is. • Identify good vs bad hypotheses. • Identify elements of good experimental design. • Identify independent and dependent variables in an experimental design. • Explain the importance of replication in experimental design. • Critique an experiment. • Improve upon a prior experimental design. • Design an experiment to test a hypothesis. • Write a good hypothesis • Identify independent and dependent variables in an experimental design • Designan experiment to test a hypothesis. • Record and analyze scientific data in a spreadsheet • Perform a statistical hypothesis test • Create graph that correctly represents scientific data • Interpret and synthesize results from a scientific experiment
2. Case Study Based Tutorial Sessions UTM – Course Design 3. Inquiry Based Labs 1. “Thinking Like a Scientist” Introductory Module Introductory Biology Course Re-Design 4. “Science vs. Pseudoscience” Lecture Examples 6. Active Learning Exercises in Lecture 5. Scientific Literacy Assignment
Lecture Intervention Lab Intervention Assessment 1. EDAT Worksheets on hypothesis Testing and experimental design included in every lab Module: Thinking Like a Scientist Module: Experimental Design Module: Critiquing Scientific Literature Group Experimental Design Brainstorming Session Group EDAT Science Process Skills Concept Assessment Science vs Pseudoscience Clicker Case Studies 12. EDAT, Final Exam
In class example - UTM • “You should take chlorophyll supplements because your need to oxygenate your bowel” (See “Bad Science” by Ben Goldacre)
Lab Intervention Assessment Week # Inquiry Lab – Optimization of ethanol production (Yeast respiration) 1. EDAT pretest Inquiry Lab: Optimization of commercial osmotic dehydration (Diffusion and osmosis) 1st Lab Practical Inquiry Lab: Optimize greenhouse photosynthetic rate (Spectrophotometry and Photosynthesis EDAT, SPARST 2nd Lab Practical Inquiry Lab: Does race exist? From Peggy Brickman (ABLE proceedings Vol. 32) (DNA electrophoresis) 16.
NDSU – Example Inquiry Lab Question Agri-gas is a company currently producing ethanol by yeast fermentation of a 5% sucrose solution at 20°C. The company would like to increase the metabolic rate of the yeast in order to maximize ethanol production. Would changing any aspect of the current production system increase the rate of yeast fermentation? Materials Incubators that can be set at 40 degrees C and 60 degrees C, refrigerator (4 degrees C), carbohydrates- sucrose(table sugar), glucose, brown sugar, powdered sugar, lamps with different color light bulbs, dark cabinets, HCl (acid), base (NaOH)
Experimental Design Aptitude Test(Sirum, 2011 Bioscience) • Students taking the EDAT are given the following prompt: • Advertisements for a herbal product, ginseng, claim that it promotes endurance. To determine if the claim is fraudulent and prior to accepting this claim, what type of evidence would you like to see? Provide details of an investigative design.
EDAT Scoring Rubric • 1 pt. is awarded for each of the following rubric items that are included in the student answer. • Recognition that an experiment can be done to test the claim • Identification of what variable is manipulated • Identification of what variable is measured • Description of how dependent variable is measured • Realization that there is one other variable that must be held constant • Understanding of the placebo effect • Realization that there are many variables that must be held constant • Understanding that the larger the sample size or number of subjects, the better the data. • Understanding that the experiment needs to be repeated. • Awareness that one can never prove a hypothesis, that one can never be 100% sure.
NDSU: Pre and Post EDAT N=517
Learning Outcomes • Write a good hypothesis • Identify independent and dependent variables in an experimental design • Designan experiment to test a hypothesis. • Record and analyze scientific data in a spreadsheet • Perform a statistical hypothesis test • Create graph that correctly represents scientific data • Interpret and synthesize results from a scientific experiment
NDSU: Additional Rubric Items 11. Identified that a hypothesis is needed/wrote a hypothesis. 12. Identified that a null hypothesis is needed for hypothesis testing, or wrote a null hypothesis. 13. Stated that treatment means need to be significantly different to reject the null hypothesis.
Future Directions • Combine the NDSU (inquiry labs) and UTM (lecture modules) interventions • Use an expandedrubric for assessment. • Use the Science Process and Reasoning Skills Test (SPARST) developed by Clarissa Dirks and Mary Pat Wenderoth.
Acknowledgements • This project was funded by a Catalytic Grant. We thank Jane Reece, the family of Neil Campbell, and Pearson for this opportunity. • Clarissa Dirks and Mary Pat Wenderoth gave us access to SPARST, which we also used as a post-test. • We also thank our students that took part in this study, and our teaching assistants.
Science Process and Reasoning Skills Test • Learning Outcome • Identify a hypothesis • Identify a controlling variable • Evaluate the quality of the experiment to test the hypothesis • Choose a supporting hypothesis • Analyze treatments and controlling for variables • Apply knowledge of appropriate controls • Select prediction • Evaluate experimental design to determine if the conclusion is warranted • Evaluate experimental designs to determine which will yield valid results • Compare and identify the variables for which one should control • Compare and identify the variables for which one should control