Research Research StrategiesStrategies

SurveysSurveysObservationsObservationsExperimentsExperiments

And other stuff…And other stuff…

Research Strategies Fall Into Research Strategies Fall Into 2 Categories2 Categories

Descriptive - strategies for Descriptive - strategies for observing observing and describingand describing behavior behavior ObservationObservation SurveysSurveys

Experiments - strategies for inferring Experiments - strategies for inferring cause and effectcause and effect relationships among relationships among variablesvariables

Longitudinal and Longitudinal and Cross-Sectional Cross-Sectional

StudiesStudies

Longitudinal StudyLongitudinal Study

Researchers study the same group Researchers study the same group of individuals for many years to see of individuals for many years to see how they change.how they change.

Drawbacks: Expensive & difficult to Drawbacks: Expensive & difficult to conductconduct

Risky – people may drop outRisky – people may drop out

Cross-Sectional StudyCross-Sectional Study

Researchers study a number of subjects Researchers study a number of subjects from different age groups and then from different age groups and then compare the results to see how they’re compare the results to see how they’re different.different.

Cheaper & easierCheaper & easier

Laboratory ObservationLaboratory ObservationThe environment can be controlled to The environment can be controlled to minimize the number of variables.minimize the number of variables.

Negatives = it may cause the subject to act Negatives = it may cause the subject to act differently than it normally would.differently than it normally would.

Ex: Skinner Box, maze, fish tankEx: Skinner Box, maze, fish tank

Naturalistic ObservationNaturalistic Observation

Subjects are observed in their “natural” Subjects are observed in their “natural” environmentenvironment

Not aware they are being watched – Not aware they are being watched – researcher does not interfereresearcher does not interfere

Could use hidden cameras or two way Could use hidden cameras or two way mirrorsmirrors

Ex: Watching students in your classes.Ex: Watching students in your classes.

Case StudyCase StudyIn depth study of one individualIn depth study of one individualUsed to investigate rare, unusual, or extreme Used to investigate rare, unusual, or extreme conditionsconditions Example: Phineas GageExample: Phineas Gage

Negatives:Negatives:Open to biasOpen to biasDifficulty of applying data from one person to Difficulty of applying data from one person to everyoneeveryone

Survey MethodSurvey Method

Relies on self-reports; uses surveys, Relies on self-reports; uses surveys, questionnaires, interviews.questionnaires, interviews.

Efficient and inexpensive methodEfficient and inexpensive method

Can you guess some Can you guess some limitationslimitations of of this method of research?this method of research?

Survey LimitationsSurvey Limitations

Accuracy = people are not always honest.Accuracy = people are not always honest.

People fear confidentiality People fear confidentiality

Example: Tooth brushing survey in 1960s. Example: Tooth brushing survey in 1960s. If as many people actually brushed their If as many people actually brushed their teeth as often as they claimed to brush teeth as often as they claimed to brush their teeth, 33% (?) more toothpaste would their teeth, 33% (?) more toothpaste would have been sold that year.have been sold that year.

Random SampleRandom Sample

Sample which represents the target Sample which represents the target population:population: Each member of the population has an Each member of the population has an

equal chance of being included.equal chance of being included. If not random then it’s biased.If not random then it’s biased. How would you pick a random sample???How would you pick a random sample???

Unfairness = Bias = incorrect conclusions.Unfairness = Bias = incorrect conclusions.

Volunteers have things in common. Peeps Volunteers have things in common. Peeps who don’t volunteer do too. who don’t volunteer do too.

Those who complete a survey are often Those who complete a survey are often willing to share. willing to share.

Participants act differently because they Participants act differently because they know they’re being observed. know they’re being observed.

BiasBias

Why would these samples Why would these samples contain bias?contain bias?

5 million motorcycle owners to represent 5 million motorcycle owners to represent American populationAmerican population

Randomly selecting people from a phone Randomly selecting people from a phone bookbook

Surveying people who subscribe to a Surveying people who subscribe to a magazinemagazine

Eliminating BiasEliminating Bias

Single Blind StudySingle Blind Study – Participants do not – Participants do not know if they are receiving the treatment or know if they are receiving the treatment or the placebothe placebo

Double Blind StudyDouble Blind Study – Neither the – Neither the participants nor the researchers know if they participants nor the researchers know if they are administering the treatment or the are administering the treatment or the placebo.placebo.

Correlational StudyCorrelational StudyExamine the Examine the relationshiprelationship of how closely one of how closely one thing is related to another thing is related to another

Collects a set of facts Collects a set of facts

Correlation reveals relationships among factsCorrelation reveals relationships among facts The higher the crime the lower the SAT scores.The higher the crime the lower the SAT scores.

Correlation studies are helpful in making Correlation studies are helpful in making predictions.predictions.

Correlation Correlation CANNOTCANNOT prove causation prove causationDoes Does NOTNOT determine determine whywhy the two variables the two variables are related--just that they are related.are related--just that they are related.

ExamplesExamples Do democratic parents produce better Do democratic parents produce better

behaved children?behaved children? Do better behaved children encourage Do better behaved children encourage

parents to be democratic?parents to be democratic?

CorrelationCorrelationPositivePositive The more days you work the more money you The more days you work the more money you

bring home each month.bring home each month.

NegativeNegative The more days you’re absent from school the The more days you’re absent from school the

lower your grades are for a class. lower your grades are for a class.

ZeroZero Does shoe size = intelligence? Does shoe size = intelligence?