CORRELATIONAL RESEARCH

• Asks what several events have in common• Asks whether knowing one event can allow

prediction of another event• Does not imply causation

Module 4: Research Strategies

*Correlation-When research shows that two traits are connected together-If one trait is there, the other is too

*Positive Correlation

*When one trait is strong, the other is too

*Negative Correlation

*If one trait is strong, the other is weak

*Zero Correlation

*There is no relationship at all between the two traits.

*However, correlation is NOT causation *One trait does not cause the other

Blue

Green

Brown

Brow

n

Red

Blonde

Hair Color

Eye

Col

or

Hair color does not CAUSE eye color

EXPERIMENT

A research method in which the researcher manipulates and controls certain variables to observe the effect on other variables.

Hypothesis- a testable prediction about the outcome of research

ACTIVITY:

Design an experiment for each of these ideas. Playing sports makes a person more/less

aggressive Women are more/less friendly than men Teenagers have more/less emotional

problems than adults People become friends with others who

are similar/different from themselves.

Experimental Research – highest constraint“True Experiment”

Control: Systematic methods

Reduce threats to validity

Limit Extraneous variables (confounds)

RANDOM ASSIGNMENT

Measurement procedures carefully designed and precisely followed

Variables

Variable - A behavior or cause of behavior that is studied through experiments

Independent Variable (IV):

The variable that a researcher changes

Each group is given a different variable

…”I” do the research…it’s what “I” control

Example 1:Group 1 gets 100mg of a drug Group 2 gets 25mg Group 3 gets a fake pill

Here the IV is DRUG (different amounts)

100 mg

25 mg

Sugar pill

IV

Independent Variable

Example 2:Either give some subjects 20, 60 or 40 watts and test

their performance on a math test

60 watts20 watts 100 watts

The IV = the amount of light

Dependent Variable:-The variable that changes because

the researcher changed the IV

-The variable that you measure

Example 1:Group 1 gets 100mg of a drug --- Sleeps for 9 hoursGroup 2 gets 25mg – Sleeps for 4.5 hoursGroup 3 gets a fake pill – Sleeps for 1 hour

Here the DV is sleep (different amounts)

100 mg

25 mg

Sugar pill

IV

Dependent Variable

Example 2:Either give some subjects 20, 60 or 40 watts and test

their performance on a math test

60 watts20 watts 100 watts

The DV = the different test scores

Dependent Variable:

Reaction time

cancer cells

errors on memory test

1.Nonscientific 2.Naturalistic Observation3.Case Study4.Correlational Research5.Quasi-experimental

Research6.Experimental Research

Types of Research = (approach to gathering data)

Lev

el o

f C

onst

rain

t

HI

LOW

HI Level of Constraint: More control = more precision

Non Scientific: ex: Historians

CONSTRUCTS: Inferences we make

ego

id

Super ego

Reification of a construct: logical error when we confuse a fact with a construct

personality

memory

An unexpected (confounding) variable??

Confounding Variables

The only thing that should change in an experiment is the independent variable. If

something else changes during the experiment, it is a

confounding variable

Confounding = confusing; causing problems

Confounding Variables-Any variable that is different for the two groups of subject-It might change the results of the study

Examples of Confounding Variables:

• Different environments– Room color– Temperature, seat comfort– Loudness

• Sample is not random• Researcher treats the groups differently

– Helps one group more– Is nicer to one group

• Subjects know the experiment and hypothesis

testing subjects on a memory test …temperature in the room is HOT …impact on the tests results

Examining the effects of alcoholon driving and obeying posted signs…but you don’t test their eyesight

examples of confounding variables

Life Expectancy

Figure 5-1. (p. 106)Graphical representation of the data in Table 5-3 showing the

characteristic pattern of

(a) high positive correlation, (b) essentially zero correlation, (c) strong negative correlation.

TRUE EXPERIMENTAL RESEARCH

• Sample is assigned to groups• The surrounding is controlled by researcher

Experimental Design

Schizophrenia and semantics

*Confounding Variable

*In an experiment, a variable other than the independent variable that could produce a change in the dependent variable

*The variable “confounds” the results

Module 4: Research Strategies*Experiments: Control for Other Confounding Variables

*Confounding Variables:

Environmental Differences

*Any differences in the experiment’s conditions--between the experimental and control groups

*Differences include temperature, lighting, noise levels, distractions, etc.

*Ideally, there should be a minimum of environmental differences between the two groups.

*Confounding Variables:

Expectation Effects

*Any changes in an experiment’s results due to the subject anticipating certain outcomes to the experiment

*Blind procedure

*An experimental procedure where the research participants are ignorant (blind) to the expected outcome of the experiment

*Sometimes called single blind procedure

*Double Blind Procedure

*A research procedure in which both the data collectors and the research participants do not know the expected outcome of the experiment.

*Both groups are ignorant (blind) to the experiment’s purpose or expected results

*Placebo

*A non-active substance or condition administered instead of a drug or active agent

*Many times an inactive pill that has no known effect

*Given to the control group

POPULATION The entire group of

people about whom you would like to know something.

Random Sample- fairly represents a population because each member of the population has an equal chance of being included.

Data and the Nature of Measurement

Research Ethics

Module 4: Research Strategies

Ethics:Human Research

(Four Basic Principles)

Module 4: Research Strategies

1. Informed Consent• Participants must be informed, in

advance, about:– the general nature of the research,

and– any potential risk. – Participants must have the right to

refuse participation or withdraw at any time.

2. Right to be Protected from Harm and Discomfort

• Studies involving harm or discomfort may be conducted only under certain circumstances, and only with the informed consent of the participants.

3. Right of Confidentiality• Individual data about research

participants should never be discussed or released.

4. Right to Debriefing• Participants have a right to receive a

complete explanation of the research at the end of the study.

• This is extremely important if the research involves deception.

Module 4: Research Strategies

*Ethics:Animal Research

*Reasons for Animal Research

*Interest in animal behavior as a topic of study

*Data from animal studies may apply to humans.

*Easier to do some type of studies (genetics) due to the shorter life span of animals

*Reasons for Animal Research

*Easier to exercise more control over experiments with animals as compared to humans

*Procedures that are not ethical to perform on humans may be considered acceptable when performed on animals

*Care of Animals used in Research

*Animals used in research must:

*Have clean housing with adequate ventilation

*Have appropriate food

*Be well cared for