RESEARCH METHODOLOGY
Our Evidence Standards
Transparency is foundational to trust. Here is exactly how CPS evaluates, grades, and communicates research evidence.
The Four-Tier Framework
Every evidence claim CPS makes is assigned one of four tiers based on the quality, quantity, and consistency of available research.
Highest level of confidence. Findings are consistent across multiple high-quality studies.
Criteria
Multiple randomized controlled trials, systematic reviews, or meta-analyses with consistent findings
Permitted Language
The evidence establishes...
Good confidence. Findings are supported by multiple studies but may have some limitations.
Criteria
Well-designed studies with replicated findings, or a single high-quality systematic review
Permitted Language
The evidence suggests...
Emerging evidence. Findings are promising but require further replication.
Criteria
Pilot studies, expert consensus, single well-designed studies, or preliminary findings
Permitted Language
Preliminary evidence indicates...
Not enough evidence to draw conclusions. Further research is needed.
Criteria
Theoretical basis only, contradictory findings, absence of relevant research, or poorly designed studies
Permitted Language
Evidence is insufficient to...
The Grading Process
Each evidence claim goes through a rigorous six-step process.
Identify the Claim
Specify the exact safety claim or question to be evaluated. Clear framing ensures the review stays focused and the resulting tier is meaningful.
Systematic Search
Conduct a comprehensive search of peer-reviewed literature using multiple databases, defined search terms, and documented inclusion/exclusion criteria.
Quality Assessment
Evaluate each study's methodology, including sample size, controls, randomization, blinding, and potential for bias using standardized assessment tools.
Evidence Synthesis
Synthesize findings across all included studies, noting consistency of results, effect sizes, and any significant limitations or conflicting evidence.
Tier Assignment
Assign an evidence tier (Strong, Moderate, Limited, or Insufficient) based on the overall quality, quantity, and consistency of the evidence.
Peer Review
Scientific Advisory Council members review and validate the assessment, ensuring methodology was followed correctly and the tier assignment is appropriate.
Study Design Hierarchy
Not all research designs are equal. This hierarchy informs how we weight different types of evidence.
| Rank | Study Design |
|---|---|
| 1 | Systematic Reviews & Meta-Analyses |
| 2 | Randomized Controlled Trials (RCTs) |
| 3 | Controlled Clinical Trials |
| 4 | Cohort Studies |
| 5 | Case-Control Studies |
| 6 | Cross-Sectional Studies |
| 7 | Case Reports & Case Series |
| 8 | Expert Opinion |
Special Assessment Rules
Certain situations require additional consideration in our grading process.
Newer therapeutic approaches may have limited RCT data. CPS evaluates them using the best available evidence while clearly noting the tier level. A Limited or Insufficient rating does not mean a therapy is harmful—only that more research is needed to establish safety and efficacy claims with confidence.
When studies produce contradictory results, CPS examines methodological differences, sample sizes, and replication attempts. The assigned tier reflects the overall weight of evidence, with conflicts noted transparently. Readers are always informed when significant disagreement exists in the literature.
Evidence may not generalize equally across populations. CPS notes when research has been conducted primarily with specific demographic groups and acknowledges limitations in generalizability. We are committed to highlighting gaps in research that affect underserved communities.
Editorial Independence
CPS maintains editorial independence from all funders and partners. No funder or partner has approval rights over CPS content, publications, or evidence ratings. The Scientific Advisory Council operates independently, and all funding sources are publicly disclosed.
Important Notes
Evidence summaries reflect the state of research at the time of publication. Psychotherapy research is continuously evolving. Publication dates are noted for transparency.
CPS does not endorse, recommend, or oppose any specific psychotherapy modality. Our work focuses on cross-cutting safety principles that apply across therapeutic approaches.