Quality appraisal of single-subject studies using the Quality Indicators within Single-Subject Research31
| Quality indicator | Lindauer et al 34 | Rosenquist et al 33 | Zarkowska36 |
| Participant description and setting | |||
| Ability to select individuals with similar characteristics | Yes | Yes | Yes |
| Replicability of participant selection process | No | No | No |
| Replicability of physical setting | Yes | Yes | Partial |
| Dependent variable | |||
| Described with operational precision | Yes | Yes | Yes |
| Measured to generate a quantifiable index | Yes | Yes | Yes |
| Measure is valid and replicable | Yes | Yes | Yes |
| Measurements repeated over time | Yes | Yes | No |
| Measures assessed in terms of reliability or interobserver agreement | Yes | Yes | No |
| Independent variable | |||
| Described with replicable precision | Yes | Yes | Yes |
| Systematically manipulated and under control of experimenter | Yes | Yes | Yes |
| Overt measure of implementation fidelity | No | Not applicable | No |
| Baseline | |||
| Repeated measurements baseline | Yes | Yes | No |
| Described with replicable precision | Yes | Yes | Yes |
| Experimental control/internal validity | |||
| Minimum of three demonstrations of experimental effect at three points in time | Yes | Yes | No |
| Controlling for threats to internal validity | Unclear | Yes | Unclear |
| Document a pattern of experimental control | Yes | Yes | Yes |
| External validity | |||
| Effects replicated across participants, settings or materials | Yes | Yes | No |
| Social validity | |||
| Dependent variable is socially important | Yes | Yes | Yes |
| Magnitude of change is socially important | Yes | Yes | Yes |
| Implementation of independent variable is practical and cost-effective | Yes | Yes | Yes |
| Implementation of independent variable over extended period of time, by typical intervention agents and in typical contexts | Yes | Yes | Yes |