Lecture #5 Scientific Process

What is science?

• The field of study concerned with discovering and describing the world around us by observing and experimenting

Different types of scientific questions

• Essential

• Comparative

• Correlative

• Descriptive

Essential

• main concept (big concept ideas)

Comparative

• One variable in different locations, organism, treatments

Correlative

• relationship between two variables

Descriptive

• description of natural system

Different types of experiments/studies

• Controlled/Manipulated

• Natural

• Observational

Controlled/Manipulated

• Variables are intentionally changed

  • Lab/Growth chamber - Highly controlled indoor study

  • Field - Conducted in a natural environment

Natural

• Uses naturally occurring differences

Observational

• No manipulation, only data collection

Tradeoffs for controlled/manipulated experiments

• More precise, can establish causation but may lack real-world applicability

Tradeoffs of observational experiments/studies

• More realistic, better for studying complex systems, but harder to establish causation

Components of a well-designed experimental study

• Replication - multiple trials or sampled

• Randomization - reduces bias

• Control group - provides a baseline for comparison

Critique of an experimental design

• Are there enough replicates?

• Is there a proper control group?

• Are variables properly controlled?

• Is the sample size sufficient?

• Are conclusions supported by data?