Reliability
Definition
The extent to which a measurement procedure produces the same result when repeated under the same conditions or by a different researcher.
- Domain
- Psychometrics
- Types
- Test-retest, inter-rater, internal consistency
- Measured as
- Correlation coefficient
- Distinct from
- Validity
Common questions
Can a test be reliable but not valid?+
Yes, a test can produce consistent scores on repeated administration while still failing to measure the construct it claims to measure.
Why does inter-rater reliability matter for forensic assessment tools?+
Many forensic instruments require a clinician to score behaviour or interview responses, so low agreement between raters undermines confidence that the resulting score reflects the examinee rather than the examiner.
Related terms
- Validity
- The degree to which evidence and theory support the interpretation of test scores for a specific purpose; modern standards treat it as...
- AUC Statistic
- Area under the receiver operating characteristic curve; the standard criterion-validity metric for forensic risk and malingering instruments, with 0.70 considered a minimum...
- Base Rate
- The prior probability of an event or proposition before specific evidence is considered. In forensic inference, the base rate is the probability...
- BSA 2023 § 39
- Section 39 of the Bharatiya Sakshya Adhiniyam 2023, the provision governing expert opinion evidence in Indian courts. Replaced Indian Evidence Act 1872...
- Consequential Validity
- The fairness and equity implications of test use; includes disparate impact on racial or cultural groups and the systematic bias this may...
- Criterion Validity
- The degree to which test scores predict or correlate with an external criterion; predictive criterion validity is most relevant to forensic instruments.
- Daubert Standard
- The US federal evidentiary standard (Daubert v. Merrell Dow Pharmaceuticals, 1993) requiring that expert testimony be based on scientifically valid methods with...
- Ecological Validity
- The degree to which a measurement or test procedure produces results that generalise from the controlled laboratory context to the real-world condition...
- Incremental Validity
- The improvement in predictive accuracy that a test adds over and above prior information; justifies the cost and burden of additional assessment.
- Interpretivism
- The view that human action has to be understood through the meaning actors themselves attach to it, which requires closeness to lived...
- Operationalisation
- The process of turning an abstract concept, such as fear of crime or recidivism, into a measurable variable with a stated procedure...
- Positive Predictive Value (PPV)
- The probability that a person who tests positive on a risk instrument will actually reoffend. PPV depends on both the instrument's sensitivity...
Explained in these topics
- Foundations of Forensic Assessment and Test ValidityConsistency of measurement: test-retest, inter-rater, and internal-consistency coefficients all quantify different aspects of this.
- Quantitative and Qualitative Research Methods in Criminology