Scientific Method

Science Science is something you know and something you do. Body of knowledge and getting answers about the natural world. Pure science seeks to answer questions about how the natural world works. Applied science uses the information from the pure sciences to solve problems Ecology is the the study of how living things interact with each other and their nonliving environments. What is science (pure and applied). Something you do and know Add sorting table on next slide

Pure or Applied Applied ecology biology environmental science physics medicine engineering chemistry

Scientific Method Observation Questions Hypothesis Experiment and Data Collection Summarizing Data Communicating Results Ecology and Scientific Method

How it Begins All science begins with observations. Lead to Questions Use your senses: see, hear, smell, feel (not taste) Use instruments: X-rays, thermometers, etc. Lead to Questions Why, how, what if. . . Asking interesting questions is the basis of all science. A Hypothesis is a testable explanation for the question or observation. A possible answer that we can investigate All science begins with observations that lead to Questions and Hypothesis Water in a balloon demo!

1 Good Design Need two groups Only change one thing (variable) Experimental group Control group Only change one thing (variable) Everything else must be kept the same. Why? 1 Good design (only test on variable) (control and experimental groups)

Studying Warblers Theory predicted that two species with identical ecological requirements would compete and push each other out. Observation: 5 species of very similar warblers live together in a northeastern spruce forest. Question: Hypothesis: Warblers example

Ways to Test a Hypothesis Observation Benefits: In the field (natural environment), can observe natural behavior Limitations: Hard to control experiment, hard to collect quantitative data Experiment Benefits: Can set-up and control experiment, focus on one thing to collect data from. Limitations: Not natural environment, can’t replicate all cases. Modeling : using computer programs to predict Benefits: predict future or what if events, don’t disturb environment. Limitations: Must include as many factors as possible in model, hard to measure all components to include, lots of assumptions must be made. Ways to test a hypothesis (3 fundamental) Energy and NPP model examples

Setting up an Experiment Hypothesis is tested under controlled conditions. Two groups are studied Only one variable changed All other variables are controlled Control group show what would happen with no treatment (normal) Why only change one thing? Experiments (variables tested under controlled conditions) Set up balloon experiment

Why Control Control groups show us that the variable we are changing is truly causing the result. If we see the same result in both the control and experimental group what does that mean? If we change more than one variable we can’t tell which one is causing the result. Value of a control group

What to do with Data Data is most useful when it has been organized and presented in easy to understand ways. Three main ways to organize data Tables Graphs (line and bar for example) Pie Charts Easier to see trends when presented Tables show numbers easily and compactly. Do not show relative relations well. Very good for non-numerical data. Line graphs are great for showing change on one thing over time. Can get confusing if too many lines. Bar graphs are great for showing several comparisons at once. Pie charts are great for showing percentages.

Examples Observation: Question: Hypothesis: Experiment: amphibian and environmental chem.

And then . . . Scientist want to share their results . . . To advance other discoveries To gain credit for their work Publish results in scientific journals Peer reviewed Searchable Science builds on science Learn from past experiments Change and update results as new information is available Sharing results