Nursing research and theory

Nursing research and theory
Theory
A theory is a broad and abstract characterization of phenomena. The theories are two types; classical and descriptive theories. Classical theory refers to an abstract generalization that presents a systematic explanation about how phenomena are interrelated. The theory explains about the phenomena and their interrelationship.
Descriptive theory describes a single phenomenon which means that describing a specific characteristic of individual or events by summarizing commonalities found in discrete observation.
Theories allow the researcher to order the observations together. It guides the researcher’s understanding not only of the ‘what’ of natural phenomena but also of the ‘why’ of their occurrence. Theories are abstractions that are created or invented by humans through observations and experiments. It shows the theorist’s ingenuity in pulling those facts together, drawing conclusion and making sense of them. It represents a theorist’s efforts to describe and explain phenomena. Based on level of generality, the theories are two types; grand (macro theories) and middle range theories. Grand theories are intended to explain large segments of the human experience (foe example, stress adaptation among human being). Middle range theories are purported to explain a portion of the human experience (for example; stress adaptation among post operative patients).
Conceptual model
Conceptual models are loosely structured and concepts are assembled based on their relevance to common theme. It presents an understanding of the phenomenon of interest and reflects the assumptions and philosophical views of the model’s designer. The conceptual models are two types: Statistical models and Schematic models. Statistical models are mathematic equations that express the nature and magnitude of relationships among a set of variables. A schematic model represents a phenomenon of interest and expresses the relationships in a diagram. Concepts are represented in boxes and relationship is represented by using directional and non directional arrows and/or symbols.
Conceptual Framework
A framework is the conceptual base of all the studies. If a study based on a theory, the framework is referred to as theoretical framework and a study based on a conceptual model, a framework called as conceptual framework. The conceptual framework helps the researcher to understand how concepts are defined and operationalised. 

Developing and testing of theory
Research plays a vital role in theory developing and testing.  Theory guides the research and researcher to assess the theory, thus, it provides a foundation for new ones.
Developing theory using qualitative research
Through qualitative research, researcher identifies patterns, communalities and its relationship among events. During the data analysis, the researcher moves from specific pieces of data to abstractions that synthesize and give structure to the observed phenomena. The main purpose is to derive a data which is grounded in reality, to provide explanation of events as they occur in reality and it should not be conceptualized in preexisting theories. 

Testing theory using quantitative research
The researchers deduce concepts in the form of hypothesis and do test through quantitative research. Then, hypotheses are predictions about how the variables would be related, if theories were correct. The researchers cannot test the theory directly, as it’s a combination of testable and non testable concepts into the form of hypothesis and test it through quantitative research. The comparison between the observed outcomes of research and the relationship predicted by the hypothesis are the major focus of the testing process.