The Scientific Method

The Scientific Method : 

The Scientific Method

What is the Scientific Method? : 

What is the Scientific Method? The scientific method is the process by which scientists, collectively and over time, work to construct an accurate representation of the world.

What is the Scientific Method? : 

What is the Scientific Method? A simple version looks something like this: 1. Observe 2. Come up with a hypothesis, that is consistent with what you have observed. 3. Use the hypothesis to make predictions. 4. Test those predictions by experiments or further observations and modify the hypothesis in the based on your results. 5. Repeat testing until there are no discrepancies between theory and experiment and/or observation.

Observations : 

Observations Observations are made by using the senses or instruments which could be described as extensions of the senses. An observation may provoke curiosity - about how things work, - why they happen or - what causes them. Observations provide the basic information leading to the formation of an hypotheses, the first step in the scientific method.

Observations : 

Observations Observations need to be: relevant Accurate Repeatable Observations may be either: Qualitative or Quantitative

Observations : 

Observations A good scientist is observant and notices thing in the world around him/herself. This can and does include reading and studying what others have done in the past because scientific knowledge is cumulative. In physics, when Newton came up with his Theory of Motion, he based his hypothesis on the work of Copernicus, Kepler, and Galileo as well as his own, newer observations. Darwin not only observed and took notes during his voyage, but he also studied the practice of artificial selection and read the works of other naturalists to form his Theory of Evolution.

?????? : 

?????? Question: The scientist then raises a question about what (s)he sees going on. The question raised must have a “simple,” concrete answer that can be obtained by performing an experiment.

Hypothesis : 

Hypothesis This is a tentative answer to the question: a testable explanation for what was observed. The scientist tries to explain what caused what was observed. An hypothesis is a limited statement regarding cause and effect in specific situations Example: suppose you discover that your car will not start. You may say, "My car does not start because the battery is low." This is your first hypothesis. You may then check whether the lights were left on, or if the engine makes a particular sound when you turn the ignition key. You might actually check the voltage across the terminals of the battery. If you discover that the battery is not low, you might attempt another hypothesis ("The starter is broken"; "This is really not my car.")

Cause : 

Cause A cause is something that makes something else happen.

Effect : 

Effect An effect is what happens because of the cause.

Slide 12: 

EXAMPLES OF CAUSE & EFFECT RELATIONSHIPS

Cause and Effect : 

Cause and Effect Today our class was very noisy. Our teacher turned off the lights to tell us to settle down. Randy got a bad sunburn. Last weekend Randy forgot to put on sunscreen. Emma went to the store to buy Ben a birthday present. Emma received an invitation to Ben’s birthday party. I was very tired today. I went to sleep very late last night. My dog Skip ran out of dog food. My dad went to the store to buy Skip some dog food.

Cause and Effect : 

Cause and Effect In a cause and effect relationship, what you observe is the effect, and hypotheses are possible causes.

Predictions : 

Predictions Next, the experimenter uses deductive reasoning to test the hypothesis.

Deductive vs. Inductive : 

Deductive vs. Inductive Inductive reasoning goes from specific observations to general conclusions: I observed cells in x, y, and z organisms, therefore all animals have cells. Deductive reasoning flows from general to specific. If all organisms have cells and humans are organisms, then humans should have cells.

Slide 17: 

Inductive or Deductive Reasoning?

Testing : 

Testing Scientist performs an experiment to see if the predicted results are obtained. If the expected results are obtained, that supports (but does not prove) the hypothesis.

Testing : 

Testing In science when testing, when doing the experiment, it must be a controlled experiment. The scientist must contrast an “experimental group” with a “control group”. The two groups are treated EXACTLY alike except for the ONE variable being tested.

What is a Variable? : 

What is a Variable? A variable is something that can be changed in the experiment. A variable is that part of the experiment that gives you your results

2 Types of Variables : 

2 Types of Variables Independent Variable - The variable whose effects are to be studied Dependant variable -The outcome. A variable that is not under the experimenter's control. It is the variable that is observed and measured in response to the independent variable.

Example : 

Example Bot thinks that his co-robots are likely to work harder on the production line if he gives them a special oil. To test this theory he decides on two groups of 20 workers each and gives Group A the special oil and Group B their normal oil. After two hours he counts how many items each group has produced. Group A has produced 1246 items and Group B has produced 1953 items. How does Bot make this a fair test? Identify the Independent variable. ( The one being varied) Identify the dependant variable. (The outcome) What does the result show? What should Bot’s conclusion be?

Testing : 

Testing The results obtained using the scientific method are repeatable