Types of Relationship Statements Type of Statement Characteristics
Axioms Consist of a basic set of statements or propositions that state the general relationship between concepts. Axioms are relatively abstract; therefore, they are not directly observed or measured.
Empirical generalizations
Summarize empirical evidence. Empirical generalizations provide some confidence that the same pattern will be repeated in concrete situations in the future under the same conditions.
Hypotheses Statements that lack support from empirical research but are selected for study. The source of hypotheses may be a variation of a law or a derivation from an axiomatic theory, or they may be generated by a scientist’s intuition (a hunch). All concepts in a hypothesis must be measurable, with operational definitions in concrete situations.
Laws Well-grounded, with strong empirical support and evidence of empirical regulatory. Laws contain concepts that can be measured or identified in concrete settings.
Propositions Statements of a constant relationship between two or more concepts or facts.
Sources: Hardy (1973); Jacox (1974); Reynolds (1971).
Theoretical statements can be classified into two groups. The first group consists of statements that claim the existence of phenomena referred to by concepts (existence statements). The second group describes relationships between concepts (relational statements) (Reynolds, 1971).
Existence Statements Existence statements and definitions relate to specific concepts and make existence claims about that concept (e.g., that chair is brown or that man is a nurse). Each statement has a concept and is identified by a term that is applied to another object or phenomena. Existence statements serve as adjuncts to relational statements and
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clarify meanings in the theory. Existence statements are also termed nonrelational statements and may be right or wrong depending on the circumstances (Reynolds, 1971).
Relational Statements Existence statements can only name and classify objects. Knowing the existence of one concept may be used to convey information about the existence of other concepts. Relational statements assert that a relationship exists between the properties of two or more concepts. This relationship is basic to development of theory and is expressed in terms of relational statements that explain, predict, understand, or control.
Like concepts, statements may have different levels of abstraction (theoretical and operational). The more general statements contain theoretically defined concepts. If the theoretical concepts are replaced with operational definitions, then the statement is “operationalized.” The two broad groups of relational statements are those that describe an association between two concepts and those that describe a causal relationship between two concepts (Reynolds, 1971).
Associational or Correlational Relationships. Associational statements describe concepts that occur or exist together (Reynolds, 1971; Walker & Avant, 2011). The nature of the association/correlation may be positive (when one concept occurs or is high, the other concept occurs or is high). For example, as the external temperature rises during the summer, consumption of ice cream increases. An example in human beings is a positive correlation between height and weight—as people get taller, in general, their weight will increase.
The association may be neutral when the occurrence of one concept provides no information about the occurrence of another concept. For example, there is no correlation between gender and scores on a pharmacology examination. Finally, the association may be negative. In this case, when one concept occurs or is high, the other concept is low and vice versa. For example, failure to use condoms regularly is associated with an increase in the occurrence of sexually transmitted infections.
Causal Relationships. In causal relationships, one concept is considered to cause the occurrence of a second concept. For example, as caloric intake increases, weight increases. In scientific research, the concept or variable that is the cause is typically referred to as the independent variable and the variable that is affected is referred to as the dependent variable.
In science, there is often disagreement about whether a relationship is causal or simply highly correlated. A classic example is the relationship between cigarette smoking and lung cancer. As early as the 1940s, an association between smoking and lung cancer was recognized, but not until the 1980s was it determined that smoking actually caused lung cancer. Likewise, genetic predisposition is associated with development of heart disease; it has not been shown to cause heart disease.
Structure and Linkages Structuring the theory by logical arrangement and specifying linkages of the theoretical concepts and statements is critical to the development of theory. The structure of a theory provides overall form to the theory. Theory structuring includes determination of the order of appearance of relationships, identification of central relationships, and delineation of direction, strength, and quality of relationships (Chinn & Kramer, 2015).
Although theoretical statements assert connections between concepts, the rationale for the stated connections needs to be developed. Theoretical linkages offer a reasoned explanation of why the variables in the theory may be connected in some manner, which brings plausibility to the theory. When developed operationally, linkages contribute to the testability of the theory by specifying how variables are connected. Thus, conceptual arrangement of statements and linkages can lead to hypotheses (Hardin, 2014).
Assumptions Assumptions are notations that are taken to be true without proof. They are beliefs about a phenomenon that one must accept as true to accept a theory, and although they may not be empirically testable, they can be argued philosophically. The assumptions of a theory are based on what the theorist considers to be adequate empirical evidence to support propositions, on accepted knowledge, or on personal beliefs or values (Jacox, 1974; Powers & Knapp, 2010). Assumptions may be in the form of factual assertions or they may reflect
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value positions. Factual assumptions are those that are known through experience. Value assumptions assert or imply what is right, or good, or ought to be (Chinn & Kramer, 2015).
In a given theory, assumptions may be implicit or explicit. In many nursing theories, they must be “teased out.” Furthermore, it is often difficult to separate assumptions that are implicit or integrated into the narrative of the theory from relationship statements (Powers & Knapp, 2010).
Models Models are schematic representations of some aspect of reality. Various media are used in construction of models; they may be three-dimensional objects, diagrams, geometric formulas, or words. Empirical models are replicas of observable reality (e.g., a plastic model of a uterus or an eye). Theoretical models represent the real world through language or symbols and directional arrows.
In a classic work, Artinian (1982) described the rationale for creating a theoretical or conceptual model. She determined that models help illustrate the processes through which outcomes occur by specifying the relationships among the variables in graphic form where they can be examined for inconsistency, incompleteness, or errors. By creating a model of the concepts and relationships, it is possible to trace the effect of certain variables on the outcome variable rather than making assertions that each variable under study is related to every other variable. Furthermore, the model depicts a process that starts somewhere and ends at a logical point. Using the model, a person should be able to explain what happened, predict what will happen, and interpret what is happening. Finally, Artinian stated that once a model has been conceptually illustrated, the phenomenon represented can be examined in different settings testing the usefulness and generalizability of the underlying theory. The figure in the exemplar at the end of the chapter shows a model illustrating the relationships between the variables of the perceived access to breast health care in African American women theory.
Theory Development Several factors are vital for nurses to examine the process of theory development. First, an understanding of the relationship among theory, research, and practice should be recognized. Second, the nurse should be aware that there are various approaches to theory development based on the source of initiation (i.e., practice, theory, or research). Finally, the process of theory development should be understood. Each of these factors is discussed in the following sections.
Relationship Among Theory, Research, and Practice Many nurses lack a true understanding of the interrelationship among theory, research, and practice and its importance to the continuing development of nursing as a profession (Pryjmachuk, 1996). As early as the 1970s, nursing scholars commented on the relationships among theory, research, and practice. Indeed, at that time, nursing leaders urged that nursing research be combined with theory development to provide a rational basis for practice (Flaskerud, 1984; Moody, 1990).
In applied disciplines such as nursing, practice is based on the theories that are validated through research. Thus, theory, research, and practice affect each other in a reciprocal, cyclical, and interactive way (Hickman, 2011; Marrs & Lowry, 2006) (Figure 4-2).