Science in General. n Definition: a systematically organized body of knowledge n Assumptions n 1. there is order in nature n 2. every event has an explanation.

Science in GeneralScience in General

Science in GeneralScience in General

Definition: a systematically organized body of Definition: a systematically organized body of knowledgeknowledge

AssumptionsAssumptions 1. there is order in nature1. there is order in nature 2. every event has an explanation2. every event has an explanation 3. we will never know everything3. we will never know everything Definitions of important termsDefinitions of important terms Variable: any trait or characteristic which can take on Variable: any trait or characteristic which can take on

a range of valuesa range of values

Science (continued)Science (continued)

Hypothesis: Question or statement about Hypothesis: Question or statement about the relationship between two or more the relationship between two or more variables i.e., is there a relationship variables i.e., is there a relationship between number of police on the streets between number of police on the streets and the crime rate?and the crime rate?

Independent variable (IV): a variable Independent variable (IV): a variable thought to have an effectthought to have an effect

Dependent variable (DV): affected variableDependent variable (DV): affected variable

Science (continued)Science (continued)

Theory: an explanation that systematically Theory: an explanation that systematically organizes observations and hypothesesorganizes observations and hypotheses

Basic vs. Applied ResearchBasic vs. Applied Research Basic--why questions; Applied--solve Basic--why questions; Applied--solve

problemsproblems Cross-sectional vs. Longitudinal ResearchCross-sectional vs. Longitudinal Research Experimental vs. Ex Post Facto ResearchExperimental vs. Ex Post Facto Research

Some notes about researchSome notes about research

Much research does not “pan out”Much research does not “pan out” Some research gets results “accidentally”Some research gets results “accidentally” Research which seems trivial sometimes turns Research which seems trivial sometimes turns

out to be important (Golden Fleece award is out to be important (Golden Fleece award is sometimes undeserved)sometimes undeserved)

We cannot assume that “commonsense” is We cannot assume that “commonsense” is correctcorrect

Study of patterns, not individualsStudy of patterns, not individuals

Errors in observationErrors in observation

Inaccurate observation (measure & record)Inaccurate observation (measure & record) Overgeneralization (sufficient number of Overgeneralization (sufficient number of

subjects, replication of studies)subjects, replication of studies) Selective observation (sufficient number)Selective observation (sufficient number) Illogical reasoning, such as gambler’s fallacy Illogical reasoning, such as gambler’s fallacy

and ex post facto reasoning (logic)and ex post facto reasoning (logic) Ego involvement, Premature closure, Ego involvement, Premature closure,

ReductionismReductionism

Research methodsResearch methods

Experiments (manipulation and control)Experiments (manipulation and control) Surveys (written and interviews)Surveys (written and interviews) Field or observational researchField or observational research Record or archival research (content Record or archival research (content

analysis, secondary analysis)analysis, secondary analysis) Case studyCase study Evaluation researchEvaluation research

TheoriesTheories

Importance of theories--they drive researchImportance of theories--they drive research Criteria for a good theoryCriteria for a good theory

1. consistent with known facts1. consistent with known facts

2. internally consistent, not contradictory2. internally consistent, not contradictory

3. parsimonious3. parsimonious

4. subject to empirical investigation4. subject to empirical investigation

5. able to predict5. able to predict

Theory buildingTheory building

Deductive reasoning: start with an Deductive reasoning: start with an explanation, derive hypotheses and test explanation, derive hypotheses and test them. ex: family instability as a result of them. ex: family instability as a result of social upheavalsocial upheaval

Inductive reasoning: gather information Inductive reasoning: gather information and then develop a theory. ex: Durkheim and then develop a theory. ex: Durkheim and crime and suicideand crime and suicide

Relationship between research and theoryRelationship between research and theory

Examples of research studiesExamples of research studies

Hirschi and social control theoryHirschi and social control theory Policewomen on patrolPolicewomen on patrol Kansas City Patrol ExperimentKansas City Patrol Experiment Group therapy in California prisonsGroup therapy in California prisons

Relationships vs. CausationRelationships vs. Causation

To be a cause, one variable must be To be a cause, one variable must be necessary and sufficient to affect another necessary and sufficient to affect another variable.variable.

Something may be necessary but not Something may be necessary but not sufficient (intelligence and good grades)sufficient (intelligence and good grades)

Could be sufficient but not necessary Could be sufficient but not necessary (isolation in early life and mental (isolation in early life and mental retardation)retardation)

Three criteria to establish a causeThree criteria to establish a cause

1. Cause must precede effect 1. Cause must precede effect 2. Two variables must be empirically 2. Two variables must be empirically

correlated (as one changes, the other changes, correlated (as one changes, the other changes, in a systematic fashion)in a systematic fashion)

3. Relationship must not be explained away by 3. Relationship must not be explained away by a third variable.a third variable.

Storks and babies, polio and pavementsStorks and babies, polio and pavements

Large family size and delinquencyLarge family size and delinquency

Relationship: child abuse & DelinquencyRelationship: child abuse & Delinquency Two methods of studyTwo methods of study RetrospectiveRetrospective Private residential treatment center, 66% Private residential treatment center, 66%

abusedabused Runaway shelter, Ohio, 75% abusedRunaway shelter, Ohio, 75% abused Juvenile delinquents, 40% abused, Juvenile delinquents, 40% abused,

neglected or abandonedneglected or abandoned

Relationship (continued)Relationship (continued)

ProspectiveProspective 5000 children referred for abuse followed: 5000 children referred for abuse followed:

after 5 years, 14% adjudicated, after 10 after 5 years, 14% adjudicated, after 10 years, 32%years, 32%

A N.Y. study found that 50% of families A N.Y. study found that 50% of families reported had at least one child taken to court reported had at least one child taken to court as delinquentas delinquent

ConclusionsConclusions

Not cause and effectNot cause and effect Need for a base rate of comparison--how Need for a base rate of comparison--how

many children are abused, and how many go many children are abused, and how many go to juvenile courtto juvenile court

There would appear to be a relationshipThere would appear to be a relationship Abused children at greater risk, higher pAbused children at greater risk, higher p Other explanatory variables for the Other explanatory variables for the

relationshiprelationship

Purposes of researchPurposes of research

Exploration--satisfy curiosity, test feasibility Exploration--satisfy curiosity, test feasibility of a study, develop methodsof a study, develop methods

Description (Census, polls)Description (Census, polls) ExplanationExplanation Units of analysis: units observed and Units of analysis: units observed and

described to create summary descriptions of described to create summary descriptions of all units and to explain differences among all units and to explain differences among themthem

Units of analysisUnits of analysis

IndividualsIndividuals Groups (i.e., families, gangs)Groups (i.e., families, gangs) Organizations (police departments)Organizations (police departments) Social artifacts (traffic accidents, court Social artifacts (traffic accidents, court

cases, prison riots)cases, prison riots)

Steps in designing researchSteps in designing research

Choosing a research problemChoosing a research problem Reviewing the literature: abstracts and Reviewing the literature: abstracts and

journals, books, collected readings, journals, books, collected readings, computer searches (NCJRS), CD ROMS, computer searches (NCJRS), CD ROMS, and the internetand the internet

Conceptualization of variables, hypotheses, Conceptualization of variables, hypotheses, questionsquestions

Steps in research (continued)Steps in research (continued)

Selecting how to measure variables Selecting how to measure variables (operationalization)(operationalization)

Selecting subjects for the study: population Selecting subjects for the study: population and sampleand sample

Method: making observations and Method: making observations and measurementsmeasurements

Data processing and analysisData processing and analysis

Steps in research continuedSteps in research continued

Interpreting the results and their Interpreting the results and their applicationsapplications

Research articlesResearch articles

Who does research?Who does research? Process for getting into printProcess for getting into print AbstractAbstract Introduction--problem, literature reviewIntroduction--problem, literature review Method--description of subjects, Method--description of subjects,

instruments, procedure, data analysis usedinstruments, procedure, data analysis used Results--descriptive and inferential statisticsResults--descriptive and inferential statistics

Research article (continued)Research article (continued)

Tables and graphs in results sectionTables and graphs in results section Discussion: interpretation of results, Discussion: interpretation of results,

cautionary notes, directions for future cautionary notes, directions for future research--the next questionsresearch--the next questions

Research proposalResearch proposal

AbstractAbstract Introduction (introduction of the topic, Introduction (introduction of the topic,

literature review, statement of what this study literature review, statement of what this study would do)would do)

MethodMethod Subjects: how many? What are their Subjects: how many? What are their

characteristics? How will they be selected?characteristics? How will they be selected? Instruments: what questions will be asked?Instruments: what questions will be asked?

Research proposal (continued)Research proposal (continued)

Procedure--how will the study be carried Procedure--how will the study be carried out? out?

Schedule: List each step, and estimate how Schedule: List each step, and estimate how much time each would take (sometimes much time each would take (sometimes steps can be done simultaneously), and steps can be done simultaneously), and indicate the total length of the projectindicate the total length of the project

Budget: List all items, the cost of each, and Budget: List all items, the cost of each, and the total costs. the total costs.

Research proposal (continued)Research proposal (continued)

Indicate supplies, travel, personnel costs, Indicate supplies, travel, personnel costs, etc. and justifyetc. and justify

Bibliography (based on Introduction--every Bibliography (based on Introduction--every reference in the introduction should have an reference in the introduction should have an entry in the bibliography, and vice versaentry in the bibliography, and vice versa

AppendicesAppendices

Layout of research proposalLayout of research proposal

AbstractAbstract

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IntroductionIntroduction

(a few paragraphs)(a few paragraphs)

Layout (continued)Layout (continued)

MethodMethod

SubjectsSubjects

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InstrumentsInstruments

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Layout (continued)Layout (continued)

ProcedureProcedure

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ScheduleSchedule

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(a table is also useful)(a table is also useful)

Layout (continued)Layout (continued)

BudgetBudget

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(again, a table may be used)(again, a table may be used)

Item CostItem Cost

Layout (continued)Layout (continued)

BibliographyBibliography

author, year of publication, title, journal, author, year of publication, title, journal, volume #, pages.volume #, pages.

Author, year of publication, title, city of Author, year of publication, title, city of publisher, publisher.publisher, publisher.

MeasurementMeasurement

Concepts, hypothetical constructs: Concepts, hypothetical constructs: theoretical ideas based on observation but theoretical ideas based on observation but which cannot be observed directlywhich cannot be observed directly

aggressivenessaggressiveness intelligenceintelligence prejudiceprejudice

MeasurementMeasurement

Difficulty of measurement of hypothetical Difficulty of measurement of hypothetical constructsconstructs

LaPiere studyLaPiere study Interchangeability of indicators: if several Interchangeability of indicators: if several

different indicators follow the same pattern, different indicators follow the same pattern, they are measuring the same conceptthey are measuring the same concept

Definition of concept: dictionaryDefinition of concept: dictionary

Operational definitionOperational definition

definition that describes how a concept will definition that describes how a concept will be measured (intelligence will be measured be measured (intelligence will be measured by the scores on the Stanford-Binet and the by the scores on the Stanford-Binet and the WAIS-R)WAIS-R)

Considerations for operational definitions: Considerations for operational definitions: reliability, validity, norms, precisionreliability, validity, norms, precision

Reliability: consistency of measurement. Reliability: consistency of measurement. Different from accuracyDifferent from accuracy

Assessing reliabilityAssessing reliability

Test-retest: Scores should not change much Test-retest: Scores should not change much over a short period of timeover a short period of time

Split-half: divide test into two parts, scores Split-half: divide test into two parts, scores should be the same on one part as on the should be the same on one part as on the other for the same individualother for the same individual

reliability affected by (1) reliability of reliability affected by (1) reliability of observers and by (2) poor questionsobservers and by (2) poor questions

ValidityValidity

Does the test measure what you want it to Does the test measure what you want it to measure?measure?

Four types of validity: face, criterion or Four types of validity: face, criterion or predictive, content, constructpredictive, content, construct

Face validity: does it appear to measure Face validity: does it appear to measure what you want it to? Do the questions what you want it to? Do the questions appear relevant?appear relevant?

Validity (continued)Validity (continued)

Criterion or predictive: does the measurement Criterion or predictive: does the measurement predict something we would like to predict? predict something we would like to predict?

Examples: ACT and success in college Examples: ACT and success in college (GPA), Screening tests and future job (GPA), Screening tests and future job performanceperformance

Determined by applying measure, and then Determined by applying measure, and then determining how well it would have predicteddetermining how well it would have predicted

Validity (continued)Validity (continued)

Content validity: degree to which a Content validity: degree to which a measure covers the range of meanings in the measure covers the range of meanings in the conceptconcept

Example: achievement test, senior test, Example: achievement test, senior test, attitude test, personality traitattitude test, personality trait

Construct: based on way a measure relates Construct: based on way a measure relates to other variables within a system of to other variables within a system of theoretical relationships (Hirschi)theoretical relationships (Hirschi)

Other considerationsOther considerations

A measure could be reliable but not valid. A measure could be reliable but not valid. It cannot be valid unless it is reasonably It cannot be valid unless it is reasonably reliablereliable

Norms: measures which provide a basis for Norms: measures which provide a basis for comparisoncomparison

Precision: fineness of distinction in Precision: fineness of distinction in measuring. How precise? In the social measuring. How precise? In the social sciences, we are not very precisesciences, we are not very precise