Limitations of a Deductive Approach Example

Method of investigation that is deductive

When conducting deductive research, you always start with a theory (the product of inductive research) (the result of inductive research). Testing these hypotheses is an essential part of deductive reasoning. You are unable to carry out research using the deductive method if there is not yet a theory.

The Four Steps that Make up the Deductive Research Approach are as Follows

Start with a theory that already exists (and create a problem statement)

• Low-cost airlines almost always experience flight delays
• All dogs have fleas
• Water is essential to the survival of all forms of life on earth

  Create a hypothesis that can be debunked based on the already accepted theory

• If a passenger chooses to fly with a low-cost airline, then they should expect to always be delayed.
• Fleas can be found on every dog that lives in my apartment complex.
• Water is essential to the survival of all land mammals.

Gather evidence to put the hypothesis to the test.

• Gather information on the flights of low-cost airlines.
• Conduct flea inspections on all of the building’s dogs.
• Study all land mammal species to see if they depend on water

Perform analysis and checks on the data.

• Only five out of every hundred flights on low-cost carriers do not experience a delay.
• Only ten of the twenty canines tested positive for fleas.
• Water is essential to the survival of every type of land animal.

Consider whether or not it is possible to reject the null hypothesis.

• 5 out of 100 flights on low-cost carriers do not experience delays; therefore, the hypothesis cannot be supported.
• That’s not enough evidence to support the theory, so we should reject it.
• Support for the concept that all terrestrial mammal species are dependent on water.

The mental process of making inferences based on deductive reasoning is referred to as deductive reasoning. If the result of an inference follows logically from its premises, meaning that it is impossible for both the premises and the conclusion to be true at the same time, then the inference can be said to be deductively valid. For instance, the conclusion that “Socrates is mortal” can be deductively justified by drawing an argument from the premises “all men are mortal” and “Socrates is a man” to arrive at the conclusion. If an argument is valid and every one of its premises is true, then the argument is sound. Some theorists define deduction in terms of the author’s intentions, contending that the author must intend for the premises to provide deductive support to the conclusion in order for deduction to be valid. It is feasible to differentiate between valid and invalid deductive reasoning with the assistance of this modification: it is invalid if the author’s view about the deductive support is erroneous, but even invalid deductive reasoning is a form of deductive reasoning.

Constraints Imposed by Taking a Logical Approach

The only way for the conclusions reached through deductive reasoning to be correct is if all of the premises established through inductive research are accurate, and if the words are unmistakable.

Example

• All dogs have fleas (premise)
• Benno is a dog (premise)
• Benno has flea (conclusion)

The conclusion that we have reached must be correct given the premises that we have. The conclusion that Benno has fleas, on the other hand, cannot be relied upon in the event that the first premise is found to be untrue.

Deductive Reasoning as a Psychological Process

Deductive reasoning as a psychological process, i.e. how humans really from inferences, is of interest to psychologists. On the other hand, logic is concerned with the deductive link of logical consequence between the premises and the conclusion, as well as how individuals should make inferences from what is presented. There are many distinct ways to think about the connection between these two things. An argument is said to be deductively valid in accordance with the semantic method if and only if there is no plausible interpretation of this argument in which its premises are true and its conclusion is incorrect. On the other hand, according to the syntactic method, an argument is only considered to have deductive validity if and only if its conclusion can be inferred from its premises using a rule of inference that is considered to be legitimate. A rule of inference is a framework for deriving a conclusion from a group of premises only on the basis of the logical structure of the premises themselves. Inference can be made using a number of different rules, such as the modus ponens and the modus tollens. Formal fallacies are a type of logical fallacy that refers to invalid deductive arguments that do not adhere to a rule of reasoning. Rules of inference are definitional rules, as opposed to strategic rules, which explain what kinds of inferences one must make in order to arrive at the conclusion that was intended. The opposite of deductive reasoning is non-deductive reasoning, often known as ampliative thinking. The premises of an ampliative argument, such as an inductive or abductive argument, provide less robust support for the argument’s conclusion. While they do increase the likelihood of the conclusion being correct, they do not guarantee that it is correct. In contrast to deductive arguments, inductive arguments might offer truly novel information that is not already covered in the premises, which allows them to compensate for this disadvantage.

The study of cognitive psychology focuses on the mental processes that are responsible for logical deduction. One of its subjects addresses the factors determining whether people form accurate or erroneous logical deductions. One of the factors is the structure of the argument; for instance, persons have a better chance of winning an argument if it takes the form of modus ponens rather than modus tollens. An additional factor is the content of the arguments: individuals are more inclined to accept the validity of an argument if the claim that is made in the argument’s conclusion is reasonable. People have a tendency to perform better when the situation is practical and specific as opposed to abstract, which is one of the usual findings. The objective of psychological theories of deductive reasoning is to provide an explanation for these findings by elaborating on the psychological processes that lie beneath them. According to the theories of mental logic, deductive reasoning is a language-like process that takes place through the manipulation of representations using rules of inference. These theories hold that this process takes place in the mind. On the other hand, mental model theories assert that deductive reasoning entails modelling potential world states without the use of rules of inference or the medium of language. There are two cognitive systems that are responsible for reasoning, and these systems are qualitatively distinct from one another, according to dual-process theories of reasoning.

Significant of Deductive Reasoning

The issue of deductive reasoning is significant to a wide variety of domains and problems. In the process of deductive reasoning, justification moves from a belief in the premises to a belief in the conclusion. The study of epistemology attempts to understand how this movement takes place. The field of study known as probability logic investigates how the probabilities of an inference’s premises influence the likelihood of its conclusion. The contentious theory of deductivism asserts that deduction is the only valid method of inference and that all other forms of inference are invalid. The method of proof known as natural deduction is one that is based on straightforward and self-evident norms of inference. The geometrical method is a methodology of philosophising in the field of philosophy that begins with a limited number of axioms that are self-evident and aims to develop a comprehensive logical system by making use of inductive and deductive reasoning.

Conclusion 

A deductive approach “develops a hypothesis based on current theory and then designs a research strategy to test the hypothesis”

“Deductive” means “from the particular to the general.” A causal relationship or link implied by a theory or case study may be valid in many circumstances. A deductive design may evaluate if the relationship or link is held in more general situations.

The deductive approach is explained by hypotheses drawn from the theory’s assertions. Deductive reasoning involves drawing conclusions from premises.

Induction begins with observations and seeks a pattern within them, while deduction begins with a predicted pattern.