The Process of Science

Science is the quest to understand nature.

Discovery Science

Emphasizes inquiry and observation

• Biology blends two main forms of scientific exploration:• Discovery Science – describes nature• Hypothesis Science – explaining nature

• Most scientist practice a combination of these two approaches.

Science as an Inquiry

• Science is way of knowing• It’s a way to answer questions about the natural

world.• Curiosity is the starting point for exploring life

through inquiry.• Inquiry is a process of investigation

• Asking questions is a natural activity for all curious minds.

Penicillin

Alexander Fleminds (1928) Scottish Physician• Was studying bacteria

• Found mold in some of his cultures

Penicillin

• Flemings was going to discard the samples when he noticed bacteria was not growing near the mold.• That led to the discovery of penicillin• This discovery lead to what we know about

antibiotics today.

Observations & Data

The questions that drive scientific inquiry are based on observation.

Observation – the use of senses; such as

vision/hearing; to gather and record

information about structures or

process.

Data - recorded observation; items of information• All observations depend on human senses.

• Scientific instruments vastly increase the range of possible observation

Scientific Instruments

Astronomy – telescopes reveal other solar systems, galaxies, etc.

Biology – microscopes

make it possible to observe life that

is invisible to the unaided eye.

Quantitative Data – Recordable observations

Is the modern form of the metric system and is generally a system of units of measurements devised around seven base units and the convenience of the number ten. It is the world's most widely used system of measurements, both in everyday

commerce and in science.

Qualitative Data – data recorded as description instead of measurements

Data can best support science when they are clearly organized, consistently recorded,

and reliable.

Inferences In Science

Inferences – a logical conclusion based on observation

• Can be from prior experience• Inference is important in science because

they help refine general questions into specific questionsNot an observation; but based on previous

observations

Inferences In Science

• Doorbell Ringing – An Observation

• Someone at the Door? – Inference• Unless you can see through the door• Could be a short circuit.

Generalization

A general conclusionThe example of the cell:• Original discovery was in the 1600’s• After many years of research it became

accepted that the cell makes up all living things.

Hypothesis Based Science

A Search for ExplanationThe grown up

concept!

Forming and Testing a Hypothesis

Hypothesis – a suggested answer to a well-defined scientific question.• An explanation on trial

• Are usually concerned with natural phenomena

• Often based on past experience of knowledge gained from discovery science or other sources

An Educated Guess

• People normally use hypothesis to solve everyday problems.

• After you propose a hypothesis – you test these ideas by making additional observations or designing an experiment.

Hypothesis – If…. Then…..

• Additional observations allows you to make predictions• These predictions are tested.

A Hypothesis is written as an If… Then… Statement.

If a particular hypothesis is correct, and you test that hypothesis with a suitable experiment, then you should expect a certain result for the experiment.

Hypothesis

• An incorrect hypothesis does not mean failure• Just wrong• The inquiry continues with test of alternative

hypothesis.Even when an experiment supports a hypothesis curiosity can send you in a new direction.

Science Generates Questions

A Case Study of Hypothesis – Based Science

A Case Study – an in-depth examination of something that actually happened

From: Observation → Question → Hypothesis

• Testing a Prediction of the Hypothesis

Designing a Controlled Experiment

Variable – A condition that can differ within the experiment

Controlled Experiment – An experiment that test the effect of a single variable• In a controlled experiment scientist try to

eliminate (or control) other variables that could affect the outcome

Variables

• Variables could include temperature, humidity (if outside), light, and other weather conditions

• Even in a lab total regulation of all but one variable is not practical.

Eliminating Unwanted Variables

A Control Group• Equals Cancelled out

Experimental Group

If…. Then….. Reasoning

Organizing Data and Interpreting Results

Often the results of an experiment only begin to make sense after much analyze of the data

Evidence in Science

Evidence – consists of a collected body of data, form observations and experiments.

• Evidence is the information upon which inferences are made.

Evidence in Science

• Evidence does NOT begin to convince scientist until observations and experiments have been repeated multiple times with similar times.• Attempts to repeat independently the

observations and experiments of others, is common in science

Repeatability is the hallmark of scientific evidence.

What makes a Hypothesis Scientific?

In science, the only hypothesis that count are those that meet the standards of testability.

Falsifiable – there must be some observation or experiment that could reveal is such a hypothesis is false.

• Scientist test a hypothesis many times and in different ways.

What makes a Hypothesis Scientific?

Even if a hypothesis that stand-up to repeated testing may later be revised or even

rejected.

• A change can occur when new tools make new kinds of observations and experiments are possible.

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Limitations of Science

Science requires repeatable observations and testable answers to hypothesis.

• These standards restrict science to a search for natural phenomena.

Limitations of Science

• Science can not or have an answer to the unobservable or supernatural forces.

Science-based knowledge = confirmed observations/testable

hypothesis

Theories in Science

• Scientist are interested in finding patterns in data• Then expand on these patterns

• Now advances in science has allowed new theories to tie together previously unrelated facts.

Theory

A well tested explanation that makes sense of a great variety of scientific observations

• Compared to hypothesis, a theory is much broader in scope.

Models

Are physical, mental, or mathematical representations of how people understand a

process or an idea.

Analogy

A comparison that shows a likeness between two things

The brain is like a computer.

Communication in Science

Many scientist work in teams and are good communicators

They share information:

Cooperation and competition characterize the scientific culture.

Science, Technology, and Society

• Science and technology are related.• Goals and methods are different

Technology – to apply scientific understanding for specific purposes.

Biologist speak of Discoveries

Technologist (engineers) Speak of Inventions