You want a mind open enough to accept radical new ideas, but not so open that your brains fall out

The Scientific Attitude: A "Baloney Detection Kit“Some things to watch for:• His descriptive of our tendency to see patterns, especially illusory

correlations

• His specific mention of confirmation bias as a source of error

• In point #3: the need for replication of research results

• In point #9: a description of the nature of scientific theories...and how they are different from what most of us casually refer to as "theories"

Experimental Design

A review of the elements of

conducting an experiment

This is the only form of research that can establish . . .

Cause and Effect

What is a Hypothesis?

This is a statement of what you think will happen given a set of circumstances. It must be able to be tested!

A hypothesis is usually brief and in this form:

• “If . . . then . . .”• Which variable is the “if” part of the

hypothesis?– independent

• Which variable is the “then” part of the hypothesis?–dependent

Your hypothesis must specify exactly how you will observe and measure behaviors you are studying!

• What is this called?Operational Definitions

Define the population you will study

What does that mean?

“Who does this apply to?”

Select a sample from the population

• Why not use the entire population?• How will you select the smaller sample?

RANDOM = everyone has an equal chance of being selected

Divide the sample into two groups

• What are those two groups called?– Control Group– Experimental Group

• Which one gets exposed to the independent variable?

Experimental Group

Compare the results of the two groups

• Evidence either SUPPORTS or DOES NOT SUPPORT the hypothesis

• What word do scientists avoid using?

Proven

Confounding Variables

1. Observer effect– Changes in behavior due to an awareness of being

watched

2. Observer bias– Experimenter focuses on results that support the

hypothesis and ignores some data

Confounding Variables

3. Experimenter effect– Giving preferential treatment to one group such

that their behavior is influenced

4. Courtesy bias– Subjects giving answers they think the

experimenter wants

Control Measures

• What can we do to make sure there are no extra variables that could potentially confuse the results?

1. Random selection of sample AND random assignment to control/experimental group

Control Measures

2. Single Blind– Controls subjects’

awareness of group assignment

3. Double Blind– Controls subject and

experimenter awareness of group assignment

Control Measures

4. Control of testing conditions

and treatments

Ethical Guidelines in Research

• Informed Consent• The right to be protected from harm and

discomfort• The right to confidentiality• The right to debriefing

Understanding Research

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