Compare methods

	Visual Analysis of Single-Case Data	Single-System Design
Field	Social Work	Social Work
Family	Process / pipeline	Process / pipeline
Year of origin	2010	2009
Originator	Applied behavior analysis tradition; codified by Kratochwill et al. (What Works Clearinghouse)	Martin Bloom, Joel Fischer & John G. Orme (codification in social work)
Type	Structured graphical judgment of intervention effect in single-case time-series data	Time-series design for evaluating intervention with a single client system
Seminal source	Kratochwill, T. R., Hitchcock, J., Horner, R. H., Levin, J. R., Odom, S. L., Rindskopf, D. M., & Shadish, W. R. (2010). Single-Case Designs Technical Documentation. What Works Clearinghouse, U.S. Department of Education.	Bloom, M., Fischer, J., & Orme, J. G. (2009). Evaluating Practice: Guidelines for the Accountable Professional (6th ed.). Pearson/Allyn & Bacon. ISBN: 9780205458066
Aliases	Visual Inspection of Single-Case Data, Single-Case Visual Analysis, Graphical Analysis of Single-Subject Data, Visual Analysis of Time-Series Graphs	Single-Subject Design, Single-Case Design, N-of-1 Design, Single-System Evaluation
Related	4	4
Summary	Visual analysis is the primary method for judging whether an intervention produced an effect in single-case and single-system designs: the data are plotted as a time series across baseline and intervention phases and read systematically for changes in level, trend, variability, immediacy of effect, overlap between phases, and consistency across similar phases. Rooted in applied behavior analysis and codified by the What Works Clearinghouse single-case standards, it treats the graph itself as the evidence and reserves the label 'effect' for changes that are clear, replicated within the design, and unlikely to reflect ordinary fluctuation.	A single-system design is a time-series approach to evaluating practice in which a single client system — an individual, family, group, or organization — is measured repeatedly on a clearly defined target before and during (and sometimes after) an intervention. By tracking the same system over time rather than comparing a treatment group to a control group, it lets a practitioner judge whether their own intervention is associated with change in the people they actually serve. It is the methodological backbone of the 'accountable professional' tradition codified by Bloom, Fischer, and Orme.