As part of your Research Matrix, you will need to identify whether the study is quantitative or qualitative, and its "level of evidence."
There are several models/systems for levels or hierarchies of evidence-based nursing practice. These models are useful when examining the evidence-based "strength" of the various publications you will find when searching databases like CINAHL, PubMed, the Cochrane Library, and Proquest Nursing and Allied Health Source.
Most models give higher ratings to systematic reviews, randomized controlled trials, and well-designed quantitative research, and lower ratings to case studies, qualitative research, and opinion-based sources.
In the following model, level I is the highest rating, and level VII is the lowest rating in terms of evidence-based publication strength:
Level I: Evidence from an experimental study, randomized controlled trials (RCTs), explanatory mixed method design that includes only a level I quantitative study, or systematic review of RCTs, with or without meta-analysis
Level II: Evidence obtained from quasi-experimental study, explanatory mixed method design that includes only a level II quantitative study, or systematic review of a combination of RCTs and quasi-experimental studies, or quasi-experimental studies only, with or without meta-analysis
Level III: Evidence obtained from nonexperimental study, systematic review of a combination of RCTs, quasi-experimental and nonexperimental studies, or nonexperimental studies only, with or without meta-analysis; exploratory, convergent, or multiphasic mixed methods studies; explanatory mixed method design that includes only a level III quantitative study; qualitative study meta-synthesis
Level IV: Opinion of respected authorities and/or nationally recognized expert committees or consensus panels based on scientific evidence and includes clinical practice guidelines and consensus panels/position statements
Level V: Based on experiential and nonresearch evidence, includes integrative reviews, literature reviews, quality improvement, program, or financial evaluation, case reports, and opinion of nationally recognized expert(s) based on experiential evidence
(from Johns Hopkins Nursing Evidence-Based Practice Grading Guidelines c2017)