impression of psychology with hopes of satisfying curiosity, many people listen to talk-radio...

Impression of Psychology

With hopes of satisfying curiosity, many people listen to talk-radio counselors and psychics to

learn about others and themselves.

Dr. Crane (radio-shrink) Psychic (Ball gazing)

The Need for Psychological Science

Intuition & Common Sense

Many people believe that intuition and common sense are enough to bring forth answers regarding

human nature.

Intuition and common sense may aid queries, but they are not free of error.

Limits of Intuition

Personal interviewers may rely too much on their “gut

feelings” when meeting with job applicants.

Psychological Science

1. How can we differentiate between uniformed opinions and examined conclusions?

2. The science of psychology helps make these examined conclusions, which leads to our understanding of how people feel, think, and act as they do!

The Need for Psychological Science

The biases and errors of people’s everyday judgments illustrate the need for:

1. Skepticism2. Humility3. Critical Thinking

The Need for Psychological Science

Critical Thinking thinking that does

not blindly accept arguments and conclusions examines

assumptions discerns hidden

values evaluates evidence

The Amazing Randi--Skeptic

Goals of Psychology

Describe Explain Predict Control

behavior and mental processes

Scientific Method Formulate testable questions

Develop hypotheses Design study to collect data

Experimental Descriptive

Analyze data to arrive at conclusions Use of statistical procedures Use of meta-analysis

Report results Publication Replication

The Need for Psychological Science Theory

an explanation using an integrated set of principles that organizes and predicts observations

For example, low self-esteem contributes to depression.

Hypothesis a testable prediction often implied by a theory People with low self-esteem are apt to feel more

depressed.

Research would require us to administer tests of self-esteem and depression.

Individuals who score low on a self-esteem test and high on a depression test would

confirm our hypothesis.

Research Observations

The Need for Psychological Science

The Need for Psychological Science

Operational Definition a statement of procedures (operations)

used to define research variables Example-

intelligence may be operationally defined as what an intelligence test measures

Testing the effects of vitamin C on the health of students could be measured by the number of colds experienced during the month.

The Need for Psychological Science

Replication repeating the essence of a

research study to see whether the basic finding generalizes to other participants and circumstances

usually with different participants in different situations

Thinking Critically …

Description The Case Study

The Survey

Naturalistic Observation

Thinking Critically …

Correlation Correlation and Causation Illusory Correlation Perceiving Order in Random

Events

Thinking Critically …

Experimentation Exploring Cause and Effect

Evaluating Therapies

Independent and Dependent Variables

Description

Psychologists describe behavior using case studies, surveys,

and naturalistic observation

Description

Case Study Psychologists

study one or more individuals in great depth in the hope of revealing things true of us all Is language uniquely human?

Case Study

A clinical study is a form of case study in which

the therapist investigates the problems associated

with a client.

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Clinical Study

Defined as a thorough, exhaustive study of a person. It includes personal, educational, family and work histories.Advantage:

A wealth of background information about one person

Disadvantages:Information cannot be generalized to others; also, researcher’s biases can influence subject’s behavior.

The Case Study Method

Description

Survey technique for ascertaining the self-

reported attitudes or behaviors of people usually by questioning a representative,

random sample of people

Survey

Wording can change the results of a survey. Even subtle changes in the order or wording of

questions can have major effects.

Q: Should cigarette ads and pornography be allowed on television? (not allowed vs. forbid)

Wording Effect

The Survey Method

Defined as asking questions of a carefully selected group of people and tabulating their answers.

Information can be gathered about feelings, opinions, and behavior patterns.

Interpretation difficult; people lie; sample may not be representative.

Advantage:

Disadvantages:

Description

False Consensus Effect tendency to overestimate the extent

to which others share our beliefs and behaviors

Population all the cases in a group, from which

samples may be drawn for a study

Samples and Sampling

Sampleselected segment of the population

Representative sampleclosely parallels the population on relevant characteristics

Random selectionevery member of larger group has equal change of being selected for the study sample

Survey

Random SamplingIf each member of a

population has an equal chance of inclusion into a

sample, it is called a random sample

(unbiased). If the survey sample is biased, its results are not valid. The fastest way to know about the

marble color ratio is to blindly transfer a few into a smaller jar and

count them.

Description

Naturalistic Observation observing and

recording behavior in naturally occurring situations without trying to manipulate and control the situation

Naturalistic Observation

Observing and recording the behavior of animals in the wild and recording self-seating patterns in a multiracial school

lunch room constitute naturalistic observation.

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The Naturalistic Observation Method

Defined as observing behaviors in their natural settings.

Disadvantages:Researcher cannot interact with the subject.

Researcher may interpret subject’s responses incorrectly.

Correlation

When one trait or behavior accompanies another, we say the two correlate.

Correlation coefficient

Indicates directionof relationship

(positive or negative)

Indicates strengthof relationship(0.00 to 1.00)

r = 0.37+

Correlation Coefficient is a statistical measure of the

relationship between two variables.

Coefficient of Correlation

Numerical indication of magnitude and direction of the relationship between two variables Positive correlation— two variables

vary systematically in the SAME direction

Negative correlation— two variables vary systematically in OPPOSITE directions

Perfect positivecorrelation (+1.00)

Scatterplot is a graph comprised of points that are generated by values of two variables. The slope

of the points depicts the direction, while the amount of scatter depicts the strength of the

relationship.

Scatterplots

No relationship (0.00)Perfect negativecorrelation (-1.00)

The Scatterplot on the left shows a negative correlation, while the one on the right shows no relationship between

the two variables.

Scatterplots

Data

Data showing height and temperament in people.

Scatterplot

The Scatterplot below shows the relationship between height and temperament in people. There

is a moderate positive correlation of +0.63.

CorrelationThree Possible Cause-Effect Relationships

(1)Low self-esteem

Depression

(2)Depression

Low self-esteem

Low self-esteem

Depression

(3)Distressing events

or biologicalpredisposition

could cause

could cause

could cause

or

or

and

Illusory Correlation

The perception of a relationship where no relationship actually exists. Parents conceive children after adoption.

Confirming evidence

Disconfirming evidence

Do not

adopt

Disconfirming evidence

Confirming evidence

Adopt

Do not conceiveConceive

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Two Random Sequences

Your chances of being dealt either of these hands is precisely the same: 1 in 2,598,960.

Order in Random Events

Given large numbers of random outcomes, a few are likely to express order.

Angelo and Maria Gallina won two California lottery games on the same day.

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Experimentation

Like other sciences, experimentation is the backbone of psychology research.

Experiments isolate causes and their effects.

Exploring Cause and Effect

Many factors influence our behavior.

Experiments (1) manipulate factors that interest us, while other factors are kept under (2) control.

Effects generated by manipulated factors isolate cause and effect relationships.

Exploring Cause & Effect

Experimentation Experiment

an investigator manipulates one or more factors (independent variables) to observe their effect on some behavior or mental process (the dependent variable)

by random assignment of participants the experiment controls other relevant factors

Experimentation Placebo

an inert substance or condition that may be administered instead of a presumed active agent, such as a drug, to see if it triggers the effects believed to characterize the active agent

Double-blind Procedure both the research participants and the

research staff are ignorant (blind) about whether the research participants have received the treatment or a placebo

commonly used in drug-evaluation studies

Hindsight Bias is the “I-knew-it-all-along” phenomenon.

After learning the outcome of an event, many people believe they could have predicted that very outcome.

We only knew the dot.com stocks would plummet after they actually did plummet.

Hindsight Bias

Overconfidence

Sometimes we think we know more than we actually know.

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would take to unscramble these anagrams?

People said it would take about 10 seconds, yet on average they took about 3 minutes (Goranson, 1978).

The Hawthorne Effect refers to the fact that some subjects will alter their behaviors simply because they know that they are part of an experiment, regardless of what is being done to them.

Experimentation

Experimental Condition (group) the condition of an experiment that

exposes participants to the treatment, that is, to one version of the independent variable

Control Condition (group) the condition of an experiment that

contrasts with the experimental treatment serves as a comparison for evaluating the

effect of the treatment

Experimental Design

Random sample— every member of the population being studied should have an equal chance of being selected for the study

Random assignment— assigning subjects to experimental and control conditions by chance.

Randomization helps avoid false results

Experimentation Independent Variable

the experimental factor that is manipulated

the variable whose effect is being studied Dependent Variable

the experimental factor that may change in response to manipulations of the independent variable

in psychology it is usually a behavior or mental process

Conducting Psychology Experiments

Hypothesis• Scientific method• Hypothesis formulation

=

Operationalization• Operationalization: to put an experiment into a form

that allows researchers to test the hypothesis• Independent variable: the variable that researchers

control

Independent variable

Dependent variable

• Dependent variable: the variable that researchers are studying

• What other questions should the researchers ask?

Operationalization• Confounding variables• Reliability• Validity

What else might cause nightmares?

What makes a movie scary?

SCARY

= ?

How can we tell if a child has had a

nightmare?

Experimenting, Recording Results, Conclusion

Recording the resultsConducting the experiment

Drawing conclusions

does cause

Correlation vs. Causation

Correlation versus causation: just because two things are related doesn’t mean one thing caused the other

Just because happened and then

happened

doesn’t necessarily mean that

caused

Replication and Theory Development

• Replication• Theory

development

==

=

Experiment 1 results

Experiment 2 results

Experiment 3 results

THEORY:

=

X amount of sleeping pills helps the healthy person with insomnia to sleep better.

Sleeping pills

Experimental Group

# of people whohad restful nights

PlacebosIndependent Variable

Groups

Dependent Variable # of people who had restful nights

The hypothesis proves to be incorrect. People taking the sleeping pill over a period of days had more insomnia than before. They had less restful sleep than the people in the control group.

Hypothesis

ControlGroup

Basic Ethical Guidelines for Psychological Researchers

Do no harm.Accurately describe risks to potential subjects.Ensure that participation is voluntary.Minimize any discomfort to participants.Maintain confidentiality.Do not unnecessarily invade privacy.Remove any misconceptions caused by deception

(debrief).Provide results and interpretations to participants.Treat participants with dignity and respect.

Evaluating Media ReportsEvaluating Media Reports• Be skeptical of sensationalist claimsBe skeptical of sensationalist claims

• Goal of “shock” media is ratingsGoal of “shock” media is ratings

• Look for original sourcesLook for original sources

• Separate opinion from dataSeparate opinion from data

• Consider methodology and Consider methodology and operational definitionsoperational definitions

• Correlation is not causalityCorrelation is not causality

• Skepticism is the rule in science.Skepticism is the rule in science.

Experimentation

FAQ

Q1. Can laboratory experiments illuminate everyday life?

Ans: Artificial laboratory conditions are created to study behavior in simplistic terms. The goal

is to find underlying principles that govern behavior.

FAQQ2. Does behavior depend on one’s culture?

Ans: Even when specific attitudes and behaviors vary across cultures, as they often do, the underlying processes are much the same.

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FAQ

Q3. Does behavior vary with gender?

Ans: Yes. Biology determines our sex, and culture further bends the genders.

However, in many ways woman and man are similarly human.

Ethical Issues

Is it right to experiment on animals?

What limits should there be?

FAQQ4. Why do psychologists study animals?

Ans: Studying animals gives us the understanding of many behaviors that may have

common biology across animals and humans.

D. Shapiro, © Wildlife Conservation Society

FAQ

Q5. Is it ethical to experiment on animals?

Ans: Yes. To gain insights to devastating and fatal diseases. All researchers who deal with animal research are required to follow

ethical guidelines in caring for these animals.

Ethical Issues Is it right to experiment on

people? What limits should there be?

FAQ

Q6. Is it ethical to experiment on people?

Ans: Yes. Experiments that do not involve any kind of physical or psychological harm beyond normal levels encountered in daily

life may be carried out.

FAQ

Q7. Is psychology free of value judgments?

Ans: No. Psychology emerges from people who subscribe to a set of values and judgments.

© Roger Shepard

FAQ

Q8. Is psychology potentially dangerous?

Ans: It can be, but it is not. The purpose of psychology is to help humanity with

problems such as war, hunger, prejudice, crime, family dysfunction, etc.

Statistical Reasoning

Statistical procedures analyze and interpret data allowing us to see what the unaided eye misses.

Composition of ethnicity in urban locales

Frequency Distribution

Frequency Distributions• 1. What are they?

– Tables– Graphs

• Bar• Histogram

Distributions

Percentile Rank--the percentage of scores that fall below a particular score. You can never have a percentile rank of 100 because you are part of that 100. (You can’t exceed yourself!)

Bar Graphs (histograms)-- Percentile ranks and distributions can be represented in bar graphs or histograms.

Histogram

Statistical Reasoning

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Statistical Reasoning

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Statistical Reasoning Mode

the most frequently occurring score in a distribution

Mean the arithmetic average of a distribution obtained by adding the scores and then

dividing by the number of scores Median

the middle score in a distribution half the scores are above it and half are

below it

Median

Separates the upper and low half of distribution

1) mean and median not necessarily equal

2) median much less sensitive to extremes

Mode

• Most common value• Always present in the distribution• May be more than one mode• Used mainly with nominal data• Plays minor role in statistical

inference

Statistical Reasoning

A Positively Skewed Distribution

15 20 25 30 35 40 45 50 90 475 710

70

Mode Median Mean

One Family Income per family in thousands of dollars

Skewed Distributions

PositiveMean > Median

NegativeMean < Median

Measures of Variation

Range the difference between the highest and

lowest scores in a distribution

Measures of Variation

Standard Deviation: A computed measure of how much scores vary around the mean.

Table 1.4Myers: Psychology, Eighth EditionCopyright © 2007 by Worth Publishers

Variation

Normal Curve--a bell-shaped curve that describes the normal distribution of many types of data. Most scores fall near the mean and fewer and fewer fall near the extremes. In a normal curve the mean, median and mode are all near the middle.

Making Inferences

A statistical statement of how frequently an obtained result occurred by experimental

manipulation or by chance.

Correlation

Regression toward the mean— falling back to the norm. It can fuel the illusion that uncontrollable events correlate with out actions.

Statistical Inference

When is it safe to generalize from a sample?

1.Representative Samples are better than biased samples.

2.Less-variable observations are more reliable than those that are more variable.

3.More cases are better than fewer. Larger samples are better than smaller ones.

4.As the size of a sample increases, the size of the standard deviation is most likely to decrease

When is a difference significant?

When sample averages are reliable and the difference between them is large we say the difference has statistical significance (it reflects a real difference not due to chance or variation between samples). For psychologists this difference is measured through alpha level set at 5 percent.