Critical Thinking in the Profession of Nursing The Delphi definitions are consistent with and supportive of Kataoka-Yahiro and Saylor's (1994) definition of critical thinking in nursing as "the critical thinking process is reflective and reasonable thinking about nursing problems without a single solution and is focused on deciding what to believe and do". This definition broadens the concept of critical thinking in nursing to include reflection of thoughts and recognition that there can be various solutions to problems. The nursing process is a scientific-problem solving model using the steps of assessment, nursing diagnosis or problem identification, planning, implementation, and evaluation in a step-by-step process to plan care for patients.