Research in PsychologyResearch in Psychology Psychology is defined as the Psychology is defined as the

scientific study of ……scientific study of ……

Introducing ResearchIntroducing Research

1.1. What does it mean to say that someone has a What does it mean to say that someone has a scientific attitude?scientific attitude?

2.2. What’s the difference between a correlational study What’s the difference between a correlational study and an experiment?and an experiment?

3.3. Identify three types of correlational studies and Identify three types of correlational studies and provide some strengths and weaknesses of each.provide some strengths and weaknesses of each.

4.4. What role do confounding variables play in an What role do confounding variables play in an experimental study? Provide some examples.experimental study? Provide some examples.

5. What role do controls play in a research study? 5. What role do controls play in a research study? (Provide some examples.) (Provide some examples.)

Why do we need research?Why do we need research?The Dangers of Common SenseThe Dangers of Common Sense Hindsight BiasHindsight Bias or “I-knew-it-all-along” or “I-knew-it-all-along”

tendency people have to view events as tendency people have to view events as more predictable than they really were.more predictable than they really were.

IntuitionIntuition : : sensing without the use of rational processsensing without the use of rational process

False Consensus effectFalse Consensus effect – tendency to – tendency to overestimate others’ agreement with usoverestimate others’ agreement with us

OverconfidenceOverconfidence

Confidence level is not a consistent predictor Confidence level is not a consistent predictor of accuracy of accuracy

The Limits of “Common Sense”The Limits of “Common Sense” Remember – Hindsight bias and Remember – Hindsight bias and

overconfidence often lead us to overconfidence often lead us to overestimate our intuition.overestimate our intuition.

We tend to remember our correct We tend to remember our correct predictions and disregard our wrong ones.predictions and disregard our wrong ones.

Research StrategiesResearch Strategies

generate or refine

research and observations

lead to

hypothesis

theories

TheoryTheory an explanation that organizes and predicts an explanation that organizes and predicts

observationsobservations Hypothesis (Hypothesis (If…, thenIf…, then…)…)

a testable prediction often implied by a a testable prediction often implied by a theorytheory

Operational DefinitionsOperational Definitions the specific procedures or steps used in the the specific procedures or steps used in the

research studyresearch study

Scientific MethodScientific Method State the ProblemState the Problem Gather InformationGather Information Form a HypothesisForm a Hypothesis Test the HypothesisTest the Hypothesis Record and Analyze DataRecord and Analyze Data State the ConclusionState the Conclusion Repeat the WorkRepeat the Work

Types of ResearchTypes of Research Correlational StudiesCorrelational Studies

Explores the strength of a relationship Explores the strength of a relationship between two or more variablesbetween two or more variables

Can make predictions, but cannot Can make predictions, but cannot explain cause and effectexplain cause and effect

IOW: Does not explain behavior, only IOW: Does not explain behavior, only describes itdescribes it

Types of Correlational StudiesTypes of Correlational StudiesCase StudyCase Study An in-depth study of one person.An in-depth study of one person. StrengthStrength: Can provide valuable insight : Can provide valuable insight

on an issue / condition on an issue / condition WeaknessWeakness: findings can rarely be : findings can rarely be

generalized to a populationgeneralized to a population Exceptions: Phineas Gage / brain injury, Exceptions: Phineas Gage / brain injury,

Piaget’s study of childhood development, Piaget’s study of childhood development, and chimpanzees and languageand chimpanzees and language..

Correlational Studies….Correlational Studies….Survey MethodSurvey Method Used to research the self-reported Used to research the self-reported

attitudes or behaviors of peopleattitudes or behaviors of people Questionnaire / Survey / interview...Questionnaire / Survey / interview... Strength: can be generalized to a Strength: can be generalized to a

larger population (if sample is random)larger population (if sample is random) Weakness: No cause and effectWeakness: No cause and effect

Wording of survey can bias the researchWording of survey can bias the research

Correlational MethodsCorrelational MethodsRandom SamplesRandom Samples Random Sample – when every person in the Random Sample – when every person in the

entire group has an equal chance of entire group has an equal chance of participating.participating.

The larger the sample size the more likely to The larger the sample size the more likely to represent the wholerepresent the whole

Ex. Computer generated list of every 5Ex. Computer generated list of every 5 thth person. person.

Why not send survey to entire school?Why not send survey to entire school?

Correlational MethodsCorrelational MethodsNaturalistic ObservationNaturalistic Observation Observing subjects in their Observing subjects in their

natural habitats / no interaction natural habitats / no interaction between researcher and subjectsbetween researcher and subjects

Strength: valuable insight into Strength: valuable insight into natural behaviornatural behavior

Weakness: no cause and effectWeakness: no cause and effect

Bias in Naturalistic ObservationBias in Naturalistic Observation Observer EffectObserver Effect: Behavior is changed : Behavior is changed

because the subject knows its being because the subject knows its being watched (animals or humans)watched (animals or humans)

Observer BiasObserver Bias: : When researchers notice what they want When researchers notice what they want

to see and ignore what doesn’t support to see and ignore what doesn’t support their theorytheir theory

Anthropomorphic FallacyAnthropomorphic Fallacy: Attributing : Attributing human thoughts, feelings, or motives to human thoughts, feelings, or motives to animals during research (especially when animals during research (especially when explaining behavior)explaining behavior)

Bias in research…Bias in research…

Experimenter EffectsExperimenter Effects: Changes in : Changes in behavior caused by the unintended behavior caused by the unintended influence of the experimenterinfluence of the experimenter

Self-Fulfilling ProphecySelf-Fulfilling Prophecy: Negative or : Negative or positive beliefs / attitudes predict positive beliefs / attitudes predict negative or positive outcomes (teacher negative or positive outcomes (teacher hears a new student is a hears a new student is a troublemaker…)troublemaker…)

Correlational Research Correlational Research Analyzing DataAnalyzing Data

Correlation Coefficient: measures the strength of a Correlation Coefficient: measures the strength of a relationship.relationship.

A Positive correlation means the presence of one A Positive correlation means the presence of one thing predicts the presence of the other thing. (2 thing predicts the presence of the other thing. (2 sets of scores rise or fall together: +1=perfect sets of scores rise or fall together: +1=perfect correlation)correlation)

A Negative correlation means the presence of one A Negative correlation means the presence of one thing predicts the absence of the other thing. (one thing predicts the absence of the other thing. (one goes up, the other down: ---1= perfect negative goes up, the other down: ---1= perfect negative

0 – no correlation0 – no correlation

Correlations: Statistical AnalysisCorrelations: Statistical Analysis Scatterplot (aka scattergram, scatter diagram)Scatterplot (aka scattergram, scatter diagram)

Graphed data that shows the strength of a Graphed data that shows the strength of a correlationcorrelation

The more the data forms a line, the The more the data forms a line, the stronger the correlation, IOW:stronger the correlation, IOW: little scatter indicates high correlationlittle scatter indicates high correlation extensive scatter = little or no correlationextensive scatter = little or no correlation

the slope of the line suggests a positive or the slope of the line suggests a positive or negative correlationnegative correlation

Research MethodsResearch Methods

Perfect positivecorrelation (+1.00)

No relationship (0.00) Perfect negativecorrelation (-1.00)

Fig. 1.9 The relationship between

years of college completed and personal

income (hypothetical data).

Research StrategiesResearch Strategies

Scatter plot of Height and TemperamentScatter plot of Height and Temperament55 60 65 70 75 80 85

959085807570656055504540353025

Temperamentscores

Height in inches

Remember…Remember… Correlations do not prove causation.Correlations do not prove causation. Correlations only make predictions about Correlations only make predictions about

the relationship between two variablesthe relationship between two variables

Example: There is a positive correlation Example: There is a positive correlation between a child watching violent TV and between a child watching violent TV and that child displaying violent behavior. Why that child displaying violent behavior. Why can we not claim that violent TV causes can we not claim that violent TV causes violent behavior?violent behavior?

So…So…

Correlation indicates the Correlation indicates the possibilitypossibility of a cause-effect of a cause-effect relationship, but relationship, but it cannot proveit cannot prove causationcausation

Illusionary CorrelationIllusionary Correlation Illusionary Correlation – If we believe there Illusionary Correlation – If we believe there

is a relationship between two things, we is a relationship between two things, we are likely to notice and recall instances are likely to notice and recall instances that confirm our belief.that confirm our belief.

Examples:Examples: More babies born during a full moon, infertile More babies born during a full moon, infertile

couples who conceive after they adopt, couples who conceive after they adopt, premonition of a phone call followed by the premonition of a phone call followed by the phone callphone call

Remember…Remember…

Correlational methods can be Correlational methods can be used in case studies, surveys, used in case studies, surveys, and field experiences.and field experiences.

Experimentation: Cause and EffectExperimentation: Cause and Effect

The experiment: the clearest, The experiment: the clearest, cleanest way to isolate cause & cleanest way to isolate cause & effect effect

Experiments manipulate variables Experiments manipulate variables to test the resultsto test the results

Know the Difference…Know the Difference… Correlational studies uncover Correlational studies uncover

naturally occurring relationships.naturally occurring relationships. experiments manipulates a experiments manipulates a

setting to determine its effect.setting to determine its effect.

Key Experimental PrinciplesKey Experimental Principles Experimental group – Group that Experimental group – Group that

receives the treatmentreceives the treatment Control group – Group that does Control group – Group that does

not receive the treatment (placebo)not receive the treatment (placebo)

Each group must be from a Each group must be from a random random sample, and randomly assignedsample, and randomly assigned

Variables (Variables (Anything that can vary…)Anything that can vary…)

Independent Variable (IV) Independent Variable (IV) the variable that is manipulated the variable that is manipulated

(example, the drug)(example, the drug) Dependent Variable (DV) Dependent Variable (DV)

the variable that is measured (example: the variable that is measured (example: behavior, or memory)behavior, or memory)

…….Variables.Variables

Determine the IV and DV in the Determine the IV and DV in the following hypothesis:following hypothesis:

IfIf you give a child sugar, you give a child sugar, thenthen the child’s activity level the child’s activity level increasesincreases..

ConfoundingConfounding Variables Variables Inconsistencies between Inconsistencies between

experimental and control groups experimental and control groups that can skew the results (bias!)that can skew the results (bias!) Examples: Time, place, frequency, Examples: Time, place, frequency,

amount etc.amount etc.

……Confounding VariablesConfounding Variables If you give a child sugar, then the child’s If you give a child sugar, then the child’s

activity level increasesactivity level increases.. What confounding principles might affect What confounding principles might affect

this experiment?this experiment? Scheduled activities after the experimentScheduled activities after the experiment Location of observed behaviorLocation of observed behavior Peer group during experimentPeer group during experiment Size of peer group during experimentSize of peer group during experiment Amount and type of sugar ingestedAmount and type of sugar ingested Time of the experimentTime of the experiment Conditions prior to the experimentConditions prior to the experiment

Controls Controls (prevent confounding variables)(prevent confounding variables) Placebos – “sugar pills” or any inert substance Placebos – “sugar pills” or any inert substance

given to the control group for a measured given to the control group for a measured comparative basis against the experimental comparative basis against the experimental groupgroup

Single blind procedure: Subjects don’t know Single blind procedure: Subjects don’t know which group they are in…which group they are in…

Double-blind procedure – neither the subjects nor Double-blind procedure – neither the subjects nor the experimenter know if the per subjects are in the experimenter know if the per subjects are in the experimental group or the control groupthe experimental group or the control group

Random sample and random assignmentRandom sample and random assignment

Remember…Remember…

Experiments aim to Experiments aim to manipulatemanipulate an an independentindependent variablevariable, , measuremeasure a a dependent variabledependent variable, and , and controlcontrol all other all other variablesvariables..

Good Research is…Good Research is… Valid – when it measures what Valid – when it measures what

the researcher set out to measure the researcher set out to measure and is accurateand is accurate

Reliable – when replication , with Reliable – when replication , with same operational definitions, same operational definitions, results in the same outcome.results in the same outcome.