Scientific Methodology Science is a way of thinking, not a process done by a few people

The Process of Science

Observing and Asking Questions Observe Ask a question Example: you observe that some marsh grass is growing taller in one location, naturally you question – why?

Inferring and Forming a Hypothesis Research your Question – Get background info first – Have other studies been done that might help? Inference – – reasonable conclusions or possible hypotheses drawn from a small sampling of data. – Example: I’ll bet the marsh grass is growing taller in that region because there is some nutrient present – I wonder what it is??– It might be nitrogen…. Prediction – – done beforehand – what is the expected outcome? Make a Hypothesis – – testable scientific explanation for a set of observations – You end up with an “If…Then…” statement – Example:

Designing Controlled Experiments Experimental design is important- need a way to test your hypothesis that keeps track of various factors that can change, or variables Examples of variables are: Why control variables??? – Independent Variable – – Dependent Variable – – Control group – – Experimental group – group where the independent variable is changed EXAMPLE: To test the marsh grass- –2 groups of grass – one control group and one experimental group –Keep all variables the same in both groups, except one (indep. var) –Therefore there is the same temperature, water amount, and nutrient amounts for both –Independent variable – the one that you change - here it is going to be nitrogen amount –Dependent variable – the one that you measure – here it is growth Which group do we change the nitrogen amount in?

Drug Trials (pharmaceuticals) Placebo (in control group) Blind test, double-blind test

Collecting and Analyzing Data Data – There are two different types of data: QualitativeQuantitative 'informal' or relative characteristics such as warmth or smellinvolves analysis of numerical data examples What type of data would the height of the plants be? How about the color of the plants? Many considerations when collect data – Sampling # of trials repeatability/reliability Using averages (mean) Graphically display your data when possible Be sure to avoid sources of error! Example: when sampling, use a large sample group to avoid changes in data due to differences in individuals.

What’s your conclusion based on this data?

Drawing Conclusions Use your data to support, refute, or revise your initial hypothesis – this will then allow you to better draw a conclusion Often times you made need to run more experiments to fully support your hypothesis A scientific theory or law represents a hypothesis, or a group of related hypotheses, which has been confirmed through repeated experimental tests As new information is gathered, theories may be amended

Reporting Your Findings: This should be published in a reputable scientific journal for others to read/evaluate/critique. = “Peer Review” is important! Why? Ex: Journal of Cell Biology, Biological Reviews, Journal of Molecular Biology, Journal of Theoretical and Applied Genetics, Journal of Ecology, Journal of Plant Biology, etc.

When Experiments are NOT Possible Ethics can also prevent experiments – especially when people are involved Example: New chemical is thought to cause cancer in humans – can’t test it on humans to find out! Example: Animal behavior study Bioethics

The Process of Science