Doing Science

Week 2 Tuesday

Announcements:

• Be sure to sit with another NEW GROUP!! 

• what should you call me...?

• OFFICE HOURS!

• Syllabus or assignment questions?

• Carbonless paper!! 

Question 1: How does science work?  What is the "scientific method?"

Question 2: How are hypotheses developed and tested?

What is a hypothesis, & how is it formulated?

Termite Wrangling Exercise:

Roles of team members:

·     Termite wrangler

·     Recorder

·     Time keeper

·     Encourager (keeps the discussion focused), collect all 4 folders at the end of class. Replace in box at front of room.

Time for activity: ~60 minutes.

Equipment: termites in small petri dish, white paper, paint brush, 1 pen & 1 pencil from the equipment supply up front

Procedure:

1.On a sheet of white paper, draw two circles (1 pen, 1 pencil) about the size of a silver dollar near each other on the center of the paper.

2.Termite wrangler -- release the termites onto the paper.

3.Team -- discuss what you observe.

4.Recorder -- take notes on carbonless paper.

5.Team -- Develop a testable question, then write it as a formal hypothesis.

6.Design a method to test the question. Everyone in the group make predictions about what you will observe. Record.

o    Termites can be placed back in their habitat while you are doing this.

7.Test the hypothesis as many times as possible.

8.Record the results.

Group discusses, getting feedback from all individuals (hint: try round-robin), and writes responses to the following questions on Carbonless Paper:

1. What was your group's hypothesis?

2. Describe the experimental design.

3.What variables were involved in your experiment?

4.What was the sample size (how many times did you do the experiment?)

5.What were the results of your experiment?

6.Based on your question, do the data support it or not support it -- explain why.

7.What are the potential sources of error in your experiment?

Place the original copy of your work in the Recorder's folder, give all folders to Encourager to put in box at front of room.

Homework: Find some background information to help assess your hypothesis about the termite behavior, and come prepared to share it with the class next time.

Science is a way of knowing - what is the nature of science?

Science is:

• Repeatable, although not all questions are testable.

• If results do not support hypothesis, investigator returns to ask questions, develop and test new hypothesis.

• Hypotheses are tested: evidence either supports or discredits the hypothesis.

• Hypotheses are never PROVEN, but if not rejected are added to the body of knowledge, allowing us to make better and better predictions about the behavior of the natural world.

What is the nature of the evidence? -- critically evaluate evidence throughout this course!

 Experimental design- terminology:

variables - dependent variables, independent variables, controlled variables

Dependent variable: what the investigator measures (or counts or records). It is what the investigator thinks will be affected by the experiment. 

Independent variable: what the investigator varies during the experiment. It is what the investigator thinks will affect the dependent variable. 

What was the dependent variable in your termite experiment?
What was the independent variable in your termite experiment?

(Other experimental terminology...:

sample size - how is it determined?  why is a large sample size usually better than a small sample size?

experimental error (use statistics)