Welcome to Welcome to Research Research

Methods and Methods and ExperimentationExperimentation

How do How do psychologists psychologists collect data collect data

about behavior?about behavior?

Regardless of the method Regardless of the method used, all research is based used, all research is based on the on the Scientific MethodScientific Method of Psychologyof Psychology

ScientificScientific means means systematic, testable, systematic, testable, and objective.and objective.

What are the three What are the three main principles main principles that guide the that guide the

Scientific Method Scientific Method of Psychology?of Psychology?

Scientific MethodScientific Method

Step 1Step 1 – Theory – TheoryStep 2Step 2 – Hypotheses – HypothesesStep 3Step 3 – Research – Research and Observationand Observation

TheoriesTheories organize organize known facts and known facts and summarizes current summarizes current research in the field.research in the field.

A A hypothesishypothesis is then is then created as created as a testable a testable predictionprediction based on based on what is currently known what is currently known and what we want to and what we want to find out.find out.

Research or observation Research or observation or experimentsor experiments are are generated to collect data, which generated to collect data, which then goes into evaluating the then goes into evaluating the hypothesis, which may or may hypothesis, which may or may not add to the existing theory.not add to the existing theory.

What are the most What are the most common methods common methods

used by used by psychologists to psychologists to

collect data?collect data?

Naturalistic Naturalistic ObservationObservation

Naturalistic Observation Naturalistic Observation Study behavior Study behavior in in a subject’s in in a subject’s naturalnatural environment. environment.

No interaction No interaction with the with the subject.subject. Is this natural?

What are some What are some potential problems potential problems with this type of with this type of research?research?

BiasBias Situation in which a Situation in which a

factor unfairly factor unfairly increases the increases the likelihood of a likelihood of a researcher reaching researcher reaching a particular a particular conclusionconclusion

Example of BiasExample of Bias I am researching teenagers behavior and I was I am researching teenagers behavior and I was

recently mugged by a group of teenagers… am recently mugged by a group of teenagers… am I likely to observe teenage behaviors as being I likely to observe teenage behaviors as being motivated by evil versus good? motivated by evil versus good?

Why?Why?

Let’s try this out Let’s try this out !!!!!!

Going for an “observational” walkGoing for an “observational” walk We are going to walk through the We are going to walk through the

buildingbuilding Your job is to write EVERY behavior Your job is to write EVERY behavior

you see… you see… When we come back to the room, ask When we come back to the room, ask

yourself “Why was ____ doing ____?”yourself “Why was ____ doing ____?” Please do not communicate with Please do not communicate with

anyone during this exercise !!!!anyone during this exercise !!!!

Case StudiesCase Studies

Case StudyCase Study In depth study of one In depth study of one

individual with the individual with the hopes of determining hopes of determining universal principlesuniversal principles

Very open to biasVery open to bias

Difficulty of applying Difficulty of applying data from one person to data from one person to everyoneeveryone

Case StudyCase Study

Case studies often Case studies often include face-to-face include face-to-face interviews, paper and interviews, paper and pencil tests, and more.pencil tests, and more.

IE. I want to know why Bart IE. I want to know why Bart killed thirty-five people over killed thirty-five people over a twenty-year period of a twenty-year period of time. I will examine the time. I will examine the police files, observe and police files, observe and interview Bart, talk to his interview Bart, talk to his and the victims families, etc.and the victims families, etc.

Difficulty of applying data from one person to everyoneDifficulty of applying data from one person to everyonebias, etcbias, etc

What are some What are some potential potential problems with problems with this type of this type of research?research?

SurveysSurveys

Survey MethodSurvey Method Research method that Research method that

relies on self-reports; uses relies on self-reports; uses questionnaires, interviews.questionnaires, interviews.

Usually a very Usually a very efficient efficient and inexpensiveand inexpensive method method to collect a lot of to collect a lot of information and create information and create basic assumptions about basic assumptions about behaviors. behaviors.

……very tricky to make a good very tricky to make a good survey!survey!

Questions need precise answersQuestions need precise answersWording must be simple: Wording must be simple: 77% of 77% of

New Yorkers interested in plants and trees, but only New Yorkers interested in plants and trees, but only 39% interested in botany; 39% interested in botany;

Don’t embarrass or humiliateDon’t embarrass or humiliate Responders will lie if there is a Responders will lie if there is a

perceived punishmentperceived punishment To longTo long Etc…Etc… Can you spot the problems….?Can you spot the problems….?

CorrelationCorrelation

Correlational StudyCorrelational StudyResearch study designed Research study designed

to determine the degree to determine the degree to which two variables are to which two variables are relatedrelated to one another to one another

IE. What is the IE. What is the relationship relationship between between exercise and exercise and weight? weight? Smoking and Smoking and cancer? Brain cancer? Brain size and size and intelligence? intelligence? Education and Education and level of income? level of income?

Is there a Is there a correlation?correlation?

What are some What are some potential potential problems with problems with this type of this type of research?research?

Watch out for Watch out for

illusory correlationsillusory correlations!! Does sugar make kids more Does sugar make kids more

hyper?hyper? Does a full moon make people act Does a full moon make people act

crazier?crazier? Does going outside with no coat Does going outside with no coat

on mean you will catch a cold?on mean you will catch a cold?

Correlational StudyCorrelational Study

Correlation studies DO Correlation studies DO NOT prove causation.NOT prove causation. They can only They can only suggestsuggest that there is or is not a that there is or is not a relationshiprelationship between the between the two variables.two variables.

IE. IE. • A correlation study may A correlation study may

suggest that people who earn suggest that people who earn higher levels of education higher levels of education generally earn higher salaries, generally earn higher salaries, but it can’t definitively say that but it can’t definitively say that getting a degree will get you a getting a degree will get you a higher paying job. higher paying job.

•

Graphing Graphing Correlation Correlation

RelationshipsRelationships

After you plot the data the After you plot the data the slope (direction) of the line slope (direction) of the line indicates whether or not indicates whether or not there is a positive, negative, there is a positive, negative, or no relationship between or no relationship between variables.variables.

How close the dots are How close the dots are together indicates how close together indicates how close the relationship between the the relationship between the variables is.variables is.

PositivePositive Correlation Correlation

As the value of one As the value of one variable increases (or variable increases (or decreases) so does the decreases) so does the value of the other value of the other variable.variable.

Studying and GradesStudying and Grades• As students study more, their grades As students study more, their grades

increase.increase.Practice and AthleticsPractice and Athletics

• As athletes practice more, their batting As athletes practice more, their batting averages increaseaverages increase

Dieting and Weight LossDieting and Weight Loss• As dieters ate less, their weight dropped.As dieters ate less, their weight dropped.

NegativeNegative Correlation Correlation

As the value of one variable As the value of one variable increases, the value of the other increases, the value of the other variable decreases.variable decreases.• The more you exercise, the less you The more you exercise, the less you

weighweigh

• The more you study, the less your The more you study, the less your teachers yell at youteachers yell at you

ZeroZero Correlation Correlation

There is no relationship There is no relationship whatsoever between the two whatsoever between the two variables.variables.• The length of your hair has no The length of your hair has no

influence on your level of influence on your level of intelligence.intelligence.

Correlational StudyCorrelational Study

Important NOT to imply a cause and Important NOT to imply a cause and effect relationship between the variableseffect relationship between the variables

Correlational study does not determine Correlational study does not determine whywhy the two variables are related--just the two variables are related--just that they are related.that they are related.

Correlational studies are helpful in Correlational studies are helpful in making predictions.making predictions.

ExperimentExperiment

ExperimentExperiment

An investigation An investigation seeking to seeking to understand understand relations of relations of cause cause and effectand effect. .

IE. I want to know if new drug A will IE. I want to know if new drug A will help to alleviate the symptoms of help to alleviate the symptoms of insomnia. Patients will be given insomnia. Patients will be given different doses at different times to different doses at different times to see what works and what doesn’t. I see what works and what doesn’t. I need to control other factors, like need to control other factors, like mattress softness and room mattress softness and room temperature, to eliminate them as temperature, to eliminate them as causes of sleep deprivation.causes of sleep deprivation.

How do I create How do I create a valid and a valid and reliable reliable experiment?experiment?

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

Step 1:Step 1: Choose a Choose a HypothesisHypothesis

Hypothesis expresses a Hypothesis expresses a perceived relationship perceived relationship between two variables. between two variables. •IE. My hypothesis is that IE. My hypothesis is that

watching violent television watching violent television shows makes people more shows makes people more aggressive.aggressive.

Step 2:Step 2: Choose VariablesChoose Variables

Variables are things Variables are things that are measured, that are measured, controlled, or controlled, or manipulated in manipulated in research.research.

The The independent variableindependent variable is the manipulated is the manipulated variablevariable..

IE. Watching television IE. Watching television violence is the independent violence is the independent variable because I can adjust variable because I can adjust what shows are viewed, for what shows are viewed, for how long, by whom, etc.how long, by whom, etc.

The The dependent variabledependent variable is is measured for change.measured for change.

IE. Measuring the change in IE. Measuring the change in aggression levels is the aggression levels is the dependent variable in our dependent variable in our experiment because it experiment because it changes based on what is changes based on what is viewed, for how long, etc.viewed, for how long, etc.

Step 3:Step 3: Identify Identify Extraneous/Confounding VariablesExtraneous/Confounding Variables

Any factor that can effect an Any factor that can effect an experiment (other than the experiment (other than the variable being studied) is variable being studied) is considered an considered an extraneous extraneous variable.variable.

IE. An extraneous variable in our IE. An extraneous variable in our experiment would be a phone call from experiment would be a phone call from a solicitor during a program that might a solicitor during a program that might make the viewer angry, the viewer make the viewer angry, the viewer receiving mail including a poor report receiving mail including a poor report card, a viewer stubbing their toe during card, a viewer stubbing their toe during a show, alcohol abuse, etc. All of these a show, alcohol abuse, etc. All of these could increase aggressiveness, but are could increase aggressiveness, but are not related to viewing violent television.not related to viewing violent television.

Step 4:Step 4: Identify Who You Will Be Identify Who You Will Be TestingTesting

The individuals on which the The individuals on which the research will be conducted are research will be conducted are called called subjects.subjects.

A small group of subjects are A small group of subjects are drawn from a larger potential drawn from a larger potential populationpopulation..

IE. Our subjects will be drawn IE. Our subjects will be drawn from the overall population of from the overall population of 1212thth grade students at grade students at Appoquinimink High School.Appoquinimink High School.

Step 5:Step 5: How Do We Decide Who How Do We Decide Who Will Be Subjects, and Who Won’t?Will Be Subjects, and Who Won’t?

Since we can’t realistically Since we can’t realistically include all 12include all 12thth graders at graders at AHS in our study, we have to AHS in our study, we have to somehow narrow down the somehow narrow down the population to more population to more manageable numbers. But manageable numbers. But how?how?

Method 1: Rigorous Control Method 1: Rigorous Control DesignDesign

Designing an experiment with Designing an experiment with specific, hand-picked groups in specific, hand-picked groups in mind. mind.

IE. Only testing males, 18 years IE. Only testing males, 18 years

old, in CP Psychology. old, in CP Psychology.

Method 2: Sample DesignMethod 2: Sample Design

A A random samplerandom sample allows allows that that every every member of an member of an overall population has overall population has an equal chance to be in an equal chance to be in the sample. the sample. • IE. Drawing names IE. Drawing names from a hat.from a hat.

Step Six: AssignmentStep Six: Assignment

Once you have chosen Once you have chosen your subjects to study, you your subjects to study, you must assign them to one of must assign them to one of two groups; those that will two groups; those that will be manipulated, and those be manipulated, and those that won’t.that won’t.

Group 1: Experimental GroupGroup 1: Experimental Group

The The experimental experimental groupgroup receives the receives the independent variable independent variable and is manipulated and is manipulated throughout the throughout the experiment.experiment.

IE. In our television violence IE. In our television violence experiment, those in the experiment, those in the experiment group will watch experiment group will watch varying degrees of violent varying degrees of violent program, for varying lengths of program, for varying lengths of time, etc., and their changes in time, etc., and their changes in levels of aggression measured.levels of aggression measured.

Group 2: Control GroupGroup 2: Control Group

The The control control groupgroup does not does not receive the receive the independent independent variable.variable.

IE. In our television violence IE. In our television violence experiment, the control group experiment, the control group will be shown a variety of will be shown a variety of non-violent programming in non-violent programming in order to create a baseline to order to create a baseline to compare the experiment compare the experiment group against.group against.

Blind ProcedureBlind Procedure An experimental procedure where the An experimental procedure where the

research participants are ignorant (blind) research participants are ignorant (blind) to the expected outcome of the to the expected outcome of the experimentexperiment

Sometimes called single blind procedureSometimes called single blind procedure

Double Blind ProcedureDouble Blind Procedure

An experimental procedure where both An experimental procedure where both the research participants and those the research participants and those collecting the data are ignorant (blind) collecting the data are ignorant (blind) to the expected outcome of the to the expected outcome of the experimentexperiment

Step 7: ReplicationStep 7: Replication

Repeating the experiment to determine Repeating the experiment to determine if similar results are foundif similar results are found

If so, the research is considered reliable.If so, the research is considered reliable.