Nature of Science

Nature of Science

August 2014Bio 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 Science1. 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