On page 4 of your notebook, write:

What is Science? How does science work? What is the purpose of science?

WARM-UP:

Set up Notebook

How to Take Notes in Biology Class

Paste to page 1 of notebook (first page after Table of Contents)

What is science?

How does science work?

What is the purpose of science?

Scientific Method Notes

(page 2)

Science is a process by which we try to understand how the natural world works.

It extends the curiosity with which we are born.

Science is… A search for understanding

Limited to the natural world

Observable

Testable, Measurable, Repeatable

Modifiable (open to change)

Disprovable

Biased

Based on experimentation

Made stronger by different lines of evidence

Science is NOT….

Based on belief or faith

Based on authority

Decided by debate or law

Rigid

Able to solve all problems

A collection of facts

Science asks questions:

What’s there?

How does it work?

How did it come to be this way?

The purpose of science is to learn about the universe.

Science is based on the idea that our senses, and extensions of those senses through the use of instruments, can give us accurate information about the Universe.

How science works…Science relies on observable evidence from the natural world.

This includes evidence of past events (geology, evolution, fossils) and those that are difficult to see (atoms, molecules).

How science works… The Scientific Method

Making ObservationsFormulating QuestionsCollecting Background InfoForming a HypothesisTesting the hypothesis through observational studies or experiments (Procedure)

Examining Results of testDrawing ConclusionsForming a new modified hypothesis

Re-testing the new hypothesis

Two Types of Observations

Qualitative

A description using adjectives.

Example: The rock has black ridges along the edge and a white spot in the middle.

Quantitative

A description using numbers to quantify.

Example: The bean plant is 12.5 centimeters tall and it has 3 new leaves.

In science, Questions are always asked!

Why did this plant grow taller than that one?

How do gorillas communicate with their young?

How do cells obtain energy?

How can birds fly?

Why do cakes rise in the oven?

Why do apples turn brown once they're cut?

How does the brain store memory?

Because people have studied the natural world for such a long time, there is a lot of scientific knowledge already.

So, one step in the scientific process is to gather background information- read books, take classes to learn about the subject, ask experts.

Observations and Background Info help us make inferences.

Inference- logical explanation based on observable facts.For example, you see a

plant wilting on a hot day. What do you infer?

Inferences help us design thoughtful experiments.

Knowing the difference between an observation and an inferences is important in an experiment.

Identifying Variables in an Experiment

The independent variable is what the experimenter changes during the experiment.

The dependent variable is what the experimenter measures.

The standardizing variables are things that are kept equal so that any changes in the dependent variable can be attributed to the changes in the independent variable.

The control group is when the independent variable is eliminated or set at a standard value.

Identifying Variables

Complete the worksheet. (10 pts)

Next, develop a hypothesis!

A hypothesis is an explanation to a question that is testable. It predicts how one variable will affect another.

A hypothesis is formatted like this:

“If… then…”

Example: If one plant is grown in the light and another plant is grown in the dark, then the one grown in the light will survive while the one grown in the dark will not survive.

Writing Hypotheses

Write Hypotheses on the handout.

10 points

How science works…Scientific explanations are tested through observational studies or experiments. If the hypothesis doesn’t work, it is rejected and revised.

Drawing Conclusions Hypotheses can be supported or rejected, but never proven.

How science works…Scientific claims are subject to peer review and replication.If it can’t be

replicated, it isn’t accepted.

This is why a well-written procedure is so important!

Science is done collaboratively.

Disagreement is the fuel between scientists. It helps them develop better ideas and come to more accurate conclusions.

Good science requires constant questioning.

So… always ask questions!

Constructing a TheoryA collection of hypotheses that have

been repeatedly tested and are supported by a great deal of evidence forms a theory.

Theories are based on evidence, allow scientists to make valid predictions, and have been tested in many ways.Examples:Theory of gravityCell theoryEvolutionary theory

Theories and “Truth”

No theory is ever accepted as absolute “truth” in science.

All theories are expected to be further tested no matter how many previous tests have been done.

Models and theories, not truth, is what science produces.

Science exists in a cultural context.

Scientists are influenced by the culture and time period in which they live. This influences what and how they study.Example: Before Galileo, geocentrism

was the rule. The geocentric model of the Universe persisted for centuries. Eventually, people came to accept that the Earth is not the center of the Universe.

Science changes.Science is always a work in progress, and its conclusions are tentative.

All ideas are open to scrutiny.

Practice: You conduct an experiment with three mice. You want to know what type of food they prefer. One mouse gets cheese, one gets carrots and the other one gets regular mouse food. You give them each 10 grams of food every day and you measure how much is left after they are done eating.

What is your independent variable?

Dependent variable?

Control group?

The Scientific Method Isopod Lab!

Scientific Method: Senses Lab

Imagine you want to know which sense is fastest- sight, touch, or hearing.

You have decided to design an experiment to test this question.

You have a ruler and a lab partner. You will drop the ruler and your lab partner will catch it. You will do it with each of the following senses: sight (they watch you drop it), sound (you tell them, “NOW”) and touch (tap their shoulder).

What is your Hypothesis?

Experimental Error

An error during an experiment in detection or measurement due to inadequate technique or the uneven application of measuring techniques.

Accuracy vs. Precision

The accuracy of a measurement system is the degree of closeness of measurements to the actual (true) value.

The precision of a measurement system, also called reproducibility or repeatability, is the degree to which repeated measurements under unchanged conditions show the same results.