Scientific Method

Ask a QuestionA. What makes a good scientific

question?1. It can be answered by direct

observation

2. It can be answered with scientific tools

B. What makes a bad scientific question?

1. It is based on values or opinions.

2. No “How” or “Why”… too general

? ??

C. Scientists may start with a broad question

1. Why do people get colds?

D. This kind of question must be broken down to more specific questions

1. Can you catch a cold from someone else?

2. Is there a relationship between getting chills and catching a cold?

E. Now state the final question in a way that can be answered by investigation or experiment

1. Does getting chilled cause colds?

F. Tips to asking good scientific questions

1. Begin by asking several questions about a topic.

2. Eliminate questions that cannot be answered by direct observation or by gathering evidence.

3. Break broad questions into smaller questions that can be investigated one at a time.

4. Word questions in a way that allows them to be answered by experiment

G. Ways to begin good testable questions:

1. “What is the relationship between…?”

2. “What factors cause…?”

3. “What is the effect of…?”

Yes, or no: Can the following topics be investigated scientifically?

1. You will remember best whatever you read just before you fall asleep.

YES

2. Taking something that belongs to another person is wrong.

NO

3. Activity will raise your heart rate.YES

As a table group, discuss and Rewrite the topic as a scientific question on the white

boards. Even groups do #1, odd groups #2

1. Some people work better in the morning, and other people work better in the afternoon.

2. You will remember best whatever you read just before you fall asleep.

Form a Hypothesis

• What is a hypothesis? Discuss with your table group, write your best definition on the whiteboard.

A. A testable statement which may include a prediction

B. May be written in a “If…. Then…Because…” format

Conduct Experiment

• When a scientist conducts an experiment, he or she investigates a phenomenon in a controlled setting to test a hypothesis.

The Variables

• A control group in an experiment is a group used for comparison.

• The experimental group is the group exposed to the factor being tested.

The Variables

• Manipulated Variable (Independent variable)—only one factor in a controlled experiment can change at a time.

The Variables

• Responding Variable (Dependent variable)—results from or depends on changes to the independent variable.

The Variables• Manipulated (Independent) Variable

– the thing you are changing• Are there levels?• How would you know?

• Responding (Dependent) Variable – the thing you are measuring

• Control or Control set-up– The thing that you do nothing to

• A level of the MV that you use as a baseline for comparison

• A level at which you know a change will not occur

Data Gathering

• Data is information gained from observations.

Quantitative Data

• Includes measurements of time, temperature, length, mass, area, volume, density, or other factors.

Qualitative Data

• Includes descriptions of what our senses detect.

Analyze the Data

• A graph of the data makes the pattern easier to grasp.

• Even when a hypothesis has not been supported, it is valuable.

Graphing…where do the variables go?

• D.R.Y. M.I.X.– Dependent Variable

– Responding Variable

– Y-axis

– Manipulated Variable

– Independent Variable

– X-axis

Title

Key

M.I.X.

D.R

.Y.

Report Conclusions

• If the reviewers agree on the merit of the paper, then the paper is published for review by the public and use by other scientists – “peer reviewed”