This lesson describes what science is, and how scientists are supposed to think when they are doing their job. It discusses the pros and cons of traditional manipulative experiments and, more common in ecology, observational experiments.
Estimated Time of Activity 45 min - 1.5 hours
- Have general grasp of the scientific method and the components of an experiment
- Understand the terms hypothesis, variable (dependant variable), factor (independent variable), observational study and manipulative study
PowerPoint (link coming soon)
1. The class begins with a brief discussion on what the students believe it means to “think scientifically.” Draw from the last class, where you defined "ecology", and ask what is the difference between a science and another academic discipline. What kind of goals are there in a scientific field vs. a humanities? How do these goals affect the way we must think? In other words, what makes science science? This lesson is short so you can spend time in this discussion and return to it at the end of the lesson.
2. This leads into a PowerPoint lecture on what science is, the scientific method and the components of an experiment (variables, factors, observational vs. manipulative designs). Then, given them the Two Trees worksheet to do in class. They should spend 10 - 15 minutes on this.
One of the early slides in the powerpoint asks how is scientific thinking different than "regular" thinking? In many ways, it is not, and a good way to teach the scientific method is to note that humans tend to use it in almost any problem-solving situation. For example, if you are trying to use a flashlight and it doesn't work you form a few hypotheses (Maybe the batteries are dead, maybe the bulb is burnt out, maybe the connections are not making contact, etc.) and proceed to test (or attempt to disprove) each one. This is basically the scientific method.
Scientific thinking however differs in some ways from normal thinking in that it requires much more organization and preparation beforehand. In particular, scientists must be especially careful of assumptions they are making about system or how they relate systems to different mathematics or statistics or models. Scientists typically look at systems much more complex and variable than a flashlight so they must be that much more careful when making predictions.
The biggest difference however is that scientists are not trying to make conclusions about a single event or item (eg, a particular flashlight) but ALL items in a defined populations (eg, all flashlights). This will be expanded on more in the stats lesson.
Assessment: Assessment at this point is mostly informal (response to discussions and readings). The Trees worksheet should be used by the teacher as assessment but is probably not worth a grade.