Scientific Method

 A sequence of steps that guide our attempts to understand a behavior or phenomenon (Bacon 1620).

 Science is a process that is guided by observation of the material world, attempts to build a framework of understanding, draws tentative conclusions, and is falsifiable.

 What does this mean?

 Epistemic mediation- science depends on OUR observations.

 Science is independently repeatable.

 Science cannot claim to prove eternal verities

Science is falsifiable. Be prepared to have your brilliant hypothesis fall apart in the harsh light of the data.

 This is a primary difference between science and faith based belief systems.

 The process of the scientific method

1). Observation:

2). Hypothesis formation:

3). Test a controlled experiment with variables that are explicitly defined operationally, so that they

Experimental treatment:

Control treatment:

Replication

All tests usually involve 2 or more hypotheses:

a) Null hypothesis (Ho)

b) Alternative hypothesis Ha) or H1

4) Conclusion: we form a tentative conclusion and determine if the results support or reject the hypothesis

5) Make new hypotheses based on deduction or induction.

C. Science usually attempts to reject the null hypothesis which is usually the simplest of the hypotheses. If you reject the null hypothesis you tend to accept an alternative hypothesis.

 Why do we disprove hypotheses?

A.Both true and false hypotheses can make predictions that appear to come true, because of unforeseen factors. If your hypothesis is that all the swans in the world are white

it is to search for a single black exception than to find all the swans in the world and determine if they are white (Popper).

 Scientists do not rely on authority, faith, or votes, but replication is essential to science. This is why the experimental design and methods should be carefully described.

After repeated tests fail to reject a powerful hypotheses it may be called a theory. Scientific theories are not half baked ideas, but powerful sets of explanations that explain many related observations.

Measurements and uncertainty

 Every measurement is an approximation.

Measurements are limited by the precision and the accuracy of the measuring instrument . In science we want a measure of uncertainty.

 Deduction versus induction

 Induction: makes general conclusions from specific observations.

Even if inductive reasoning makes use of facts that are all correct, the conclusion may still be false.

2.Deduction- makes specific predictions from generalized principles.

Scientists use induction to develop generalizations, then use deduction to test if the conclusions are false.