Two Faces of Causality: A Small Two Faces of Causality: A Small Case Study of the Admission of Case Study of the Admission of

Scientific Evidence to Show Scientific Evidence to Show Causality in a Bias and a Toxic Causality in a Bias and a Toxic

Tort Case in the 4th CircuitTort Case in the 4th Circuit

Christina Kirk PikasChristina Kirk PikasLBSC 735: Legal Issues in Information LBSC 735: Legal Issues in Information

ManagementManagementDecember 11, 2002December 11, 2002

OverviewOverview

Review of the efforts made to form Review of the efforts made to form the admissibility of scientific evidence the admissibility of scientific evidence

Discussion of causality and the Discussion of causality and the scientific and the statistical methods scientific and the statistical methods used to proveused to prove

Case studies of two cases:Case studies of two cases: Product liabilityProduct liability Pay discriminationPay discrimination

Admission of Expert EvidenceAdmission of Expert Evidence

1919thth century century FryeFrye (1923) (1923) Federal Rules of EvidenceFederal Rules of Evidence (1975) (1975) DaubertDaubert Trilogy Trilogy

DaubertDaubert (1993) (1993) JoinerJoiner (1997) (1997) KumhoKumho (1999) (1999)

CausalityCausality Definition: “The principle of causal Definition: “The principle of causal

relationship; the relation between cause relationship; the relation between cause and effect” (and effect” (Black’s Law DictionaryBlack’s Law Dictionary))

Cause: “To bring about or effect” (Cause: “To bring about or effect” (Black’s Black’s Law DictionaryLaw Dictionary))

Correlation, association, or statistically Correlation, association, or statistically significant relationship is not enoughsignificant relationship is not enough

Primary issue in Primary issue in Toxic tortsToxic torts Product liabilityProduct liability Discrimination Discrimination

General vs. Specific CausalityGeneral vs. Specific Causality

General (examples: toxicology, General (examples: toxicology, epidemiology)epidemiology) anecdotal evidenceanecdotal evidence observational studiesobservational studies controlled experimentscontrolled experiments

SpecificSpecific Treating DoctorTreating Doctor Series of specific details such asSeries of specific details such as

•Biological plausibility•Consideration of alternate hypotheses•Cessation of exposure

•Temporal relationship•Strength and specificity of association•Dose-response relationship•Consistent with other knowledge

Case 1: Nettles v. Proctor & Case 1: Nettles v. Proctor & GambleGamble

Ms. Nettles used Vicks Sinex Nasal Ms. Nettles used Vicks Sinex Nasal Spray and later became blindSpray and later became blind

A neuro-opthalmologist was A neuro-opthalmologist was produced to give evidence on her produced to give evidence on her casecase No studies existed linking the main No studies existed linking the main

ingredient to her conditioningredient to her condition Only temporal connection was foundOnly temporal connection was found

As per Joiner – court did was neither As per Joiner – court did was neither arbitrary or capricious, decision was arbitrary or capricious, decision was affirmed affirmed

Case 2: Smith, et al v. Virginia Case 2: Smith, et al v. Virginia Commonwealth UniversityCommonwealth University

VCU employed a committee to VCU employed a committee to determine if there was a discrepancy determine if there was a discrepancy in pay between male and female in pay between male and female tenure and tenure-track professorstenure and tenure-track professors

The committee used a multiple The committee used a multiple regression analysis and determined regression analysis and determined that there was a $1,300 difference. that there was a $1,300 difference. Another committee was started to Another committee was started to review CVs and give deserving female review CVs and give deserving female employees appropriate raises.employees appropriate raises.

Case 2: continuedCase 2: continued

Plaintiffs AllegePlaintiffs Allege Not fair because raises based only on genderNot fair because raises based only on gender Inflated pool – more males had been Inflated pool – more males had been

administrators and therefore had higher payadministrators and therefore had higher pay Analysis not valid because did not take into Analysis not valid because did not take into

account major factors relating to pay, account major factors relating to pay, namely performancenamely performance

Trial CourtTrial Court Proxies were sufficient, regression study Proxies were sufficient, regression study

valid, pay handed out fairly, to correct valid, pay handed out fairly, to correct inequityinequity

Summary Judgment awarded to VCUSummary Judgment awarded to VCU

Case 2: ContinuedCase 2: Continued

Appeals CourtAppeals Court Regression did not take into account Regression did not take into account

performance factors, not invalid, but performance factors, not invalid, but probative value in questionprobative value in question

If material issues exist, should not have If material issues exist, should not have been a Summary Judgment, reversed.been a Summary Judgment, reversed.

AnalysisAnalysis If the lower court had employed If the lower court had employed DaubertDaubert

factors, the summary judgment was factors, the summary judgment was correctcorrect

The initial study was invalid – it poorly fit The initial study was invalid – it poorly fit the real situation under studythe real situation under study

ConclusionConclusion

Complexity of new cases, commingling Complexity of new cases, commingling of evidence, junk science make the of evidence, junk science make the gatekeeper role very importantgatekeeper role very important Judges see expert evidence 90 days Judges see expert evidence 90 days

before trialbefore trial Many courses, books, and studies exists Many courses, books, and studies exists

to help train judgesto help train judges Judges can appoint neutral experts to Judges can appoint neutral experts to

help interpret the evidencehelp interpret the evidence

More ConclusionsMore Conclusions

Scientific methods and statistics are Scientific methods and statistics are being used for purposes for which being used for purposes for which they were not designedthey were not designed Statistics don’t prove anything – give Statistics don’t prove anything – give

relative probabilityrelative probability Toxicology and epidemiology – give Toxicology and epidemiology – give

relative riskrelative risk Statistical significance and practical Statistical significance and practical

significance are not the samesignificance are not the same

FinallyFinally

DaubertDaubert provides a useful framework provides a useful framework if flexibly employedif flexibly employed

Resulting summary judgments save Resulting summary judgments save time and moneytime and money

It’s still easy to lie with statisticsIt’s still easy to lie with statistics