Nature of Science

August 2014

Bio X

From the Solutions Lab

• What do you observe? Look for patterns in the “data.”

• What do you infer each solution to be?

• What evidence do you have for your inference?

• How confident are you in your answer?

• What would make you more sure?

How is what you were doing like science?

• Based on evidence/data (empirical)• You made inferences from

observations• Your ideas are never 100% sure

and could change with more data (tentative)

• You worked with others (collaborative)

• Your ideas were checked by each other (peer review)

• You used your background knowledge to guide your inferences (subjective)

Nature of Science

1. Empirical – based on data, testable

2. Tentativeness – subject to change, never certain, 100%

3. Observation vs. Inference – inferences make sense of observations, consistent with patterns in data

4. Subjectivity – each person’s background knowledge & scientific conceptual framework impact how they view data and even their observations

5. Collaborative – scientists work with each other, within individual labs as well as by building on each other’s findings throughout the world

6. Peer Reviewed – scientists make their findings public (presentations or publications) and findings are reviewed by other scientists

Science is limited – it can only address questions about things that can be observed.

What Is Science?

• Latin word scientia = knowledge

• Search for knowledge

• Something is science if it can be experimentally tested over and over

• It is objective and unbiased

Limitations of Science

• Science cannot answer questions regarding judgment

• Questions involving vague or intangible concepts (superstitions, “bad luck”) cannot be answered by science

• Many times, scientific experiments don’t yield answers but lead to more questions.

Types of Science

• Pure science- done to learn more and gain knowledge (for the sake of knowing)– Ex. Experiment used to learn how a new drug

works

• Applied science- puts knowledge to use– Ex. Using the drug to treat an illness

Branches of Science

• Biology

• Zoology

• Chemistry

• Physics

• Astronomy

• Botany

• Hydrology

• Physiology

• Biochemistry

• many many more!

How Do We Study Science?

• Make an initial observation

• Formulate a hypothesis

• Design an experiment

• Test hypothesis (conduct experiment)

• Collect Data

• Analyze Data

• Draw conclusions

• Communicate findings

Initial Observation

• Curiosity is the beginning of experimentation

• The scientific method generally begins with an unexplained observation about nature.

• Observations lead to questions

Forming A Hypothesis

• Possible answer to a scientific question

• TESTABLE!

• From the hypothesis made, scientists can make predictions that logically follow the hypothesis that was made

Experiment Design

• Plan out how you will test your hypothesis

• Performing the Experiment:– Designate a control group– Designate an experimental group

• Independent Variable• Dependent Variable

Performing an Experiment

• Control: standard to which you measure experimental results to

• Independent Variable: factor that is being tested

• Dependent Variable: responding variable (“depends” on the independent variable)

• Constant: factor(s) that remain the same in an experiment.

Collecting & Analyzing Data

• Quantitative Data vs. Qualitative Data– Quantitative: measurements (numbers)

• Must determine if results are reliable (errors?)• Compare results

– Charts/Tables– Graphs (Bar graphs, Line graphs, Pie Charts)

– Qualitative: descriptions • Ex.: descriptions of behavior, color changes, etc.

Drawing Conclusions

• Biologists analyze their tables, graphs & charts to determine if a hypothesis is supported or not

• Scientists make inferences from data– Inference: conclusion made on the basis of

facts and previous knowledge rather than on direct observations

• Scientists communicate their findings

Theory vs. Law

• Theory: Highly tested and confirmed idea that can explain a great amount of data.– Ex: Theory of evolution, Cell theory

• Law: Statement of fact that explains an action or set of actions. It is generally accepted to be true and universal– Ex: Law of gravity