What is the inductive and deductive method?

This article seeks to discern between the inductive method and the deductive method, through these research strategies we can reach methodical conclusions that facilitate learning.

With these two educational models, we can cover analysis from a very general topic to a very specific one. This article is ideal for any investigative, curious and analytical person who wants to know the concepts of these two methods.

What is the inductive method?

In this investigative approach, the premises are the basis of the conclusion, in order to obtain a final result based on the investigation through the inductive method, it is necessary to have factors that speed up the analysis as premises. The conclusion is safe since it is based on probable evidence.

Within the different meanings, we find the concept that encompasses all the general principles until reaching a specific observation of the phenomenon, problem or object under study.

On the other hand, to carry out an investigation based on the inductive method, different analysis strategies are used that do not leave out any characteristic that determines the structure of the problem, for this, it goes from the most general ideas to the most specific ones.

This method is also frequently used by the scientific method, creating the possibilities of specifying a hypothesis and explaining theories.

Types of inductive reasoning

To fully explain what the inductive method encompasses, we wanted to demonstrate its characteristics according to the following types:

Generalization

It is a premise that is based on the common factor of the population, the object is studied a priori and then a conclusion is given based on what was first seen. In colloquial language we find some examples such as the following:

Examples of generalization

• "I have met an older and wealthy man who is the partner of a young woman, surely all young women are looking for an older man with money."
• "Today I met my course tutor, he's a bore, sure all the other tutors are the same."
• "I bought two jars of mayonnaise and one has gone wrong, surely the other is also damaged."
• "I have met a Catholic who is very fanatical, therefore all Catholics are very fanatics."
• "I have looked at some pages of a self-help book and it seemed fatal to me, so all self-help books are fatal."
• "My girlfriend's mother makes very bad spaghetti, for sure they are the same for her."

Statistical syllogism

It is based on the study of different factors according to statistics, for example, a portion Y of a population J has an attribute A, therefore, an individual X is a member of J.

Thus, there is a probability corresponding to Y that X has A.

Examples of statistical syllogism

1. Most elementary school students have head lice.
2. Alberto is an elementary school student.
3. Alberto has a high chance of getting head lice.

• Women cannot consume coffee
• Bakers consume coffee.
• No baker is a woman.

1. All dogs are aggressive
2. No cat is aggressive
3. No cat can be a dog.

• 78% of men who work in mining are homosexual.
• Antonio is a miner
• There is a 78% probability that Antonio is homosexual.

1. Usually women shave their legs.
2. I'm a woman
3. I shave my legs.

Simple induction

It is a simple conclusion of the events that occur around another individual, for example, a portion Y of a population J has an attribute A, therefore, an individual X is a member of J.

Thus, there is a probability corresponding to Y that X has A.

Simple induction examples

1. Juan gave me a pair of shoes and one was damaged, then my father gave me another pair of shoes and one was damaged, finally, my brother gave me one more pair of shoes and one was damaged; That means that every time they give me shoes one damages me.
2. On Monday I worked and I did not finish the reports that they asked me, on Tuesday I went to work and I could not finish the reports that they asked me either, today I had to work and I did not finish the reports; That means that the times I go to work I cannot fulfill my responsibilities.
3. On Saturday I went to María's store to buy chocolate cookies and there were only vanilla cookies, on Sunday I also went and there were only vanilla cookies, today Pablo went to María's store and bought chocolate cookies; This means that I will never be able to buy chocolate chip cookies if I go to the store alone.

Argument from analogy

This method refers to two processes that are related, for example, H and A are similar to the properties of X, Y and Z. In turn, it has been observed that element H has an element B, therefore, A probably also has an element B.

Examples of argument from analogy

1. Light is to darkness as heat is to cold.
2. Fear is shouting like laughter to happiness.
3. Sadness is to tears like tiredness to silence.
4. The radio is to the ear like the television to the sight.
5. The comb is to the hair like the shoes to the feet.
6. Bear is to forest as lion is to jungle.
7. Perfume is to cleaning as a bad smell of dirt.
8. Spain is to Madrid as France is to Paris.
9. The sweater is cold as the short is hot.
10. Sweating is to exercises like fat to sedentary lifestyle.

Casual inference

It is a conclusion drawn from the relationship of a chance event with respect to an accompanying factor.

Premises that demonstrate the relationship between both things, can affect the relationship between them.

Examples of casual inference

1. All the dogs in a veterinary office have come for tick problems, they are all of different breeds and sizes and have different lifestyles; However, all women have come with their owners, all have declared that the hygiene habits they gave the dog were very careless, so the veterinarian comes to the conclusion that dogs that have owners are prone to having ticks .
2. A psychological clinic receives 7 patients with sleep disorders. A study carried out on the 7 patients concluded that 2 of them had witnessed parents with the same problem in their childhood, and 5 of them had had a full childhood; Researchers conclude that having parents with sleep disorders does not directly infer the same problem as an adult.
3. A foster home receives 10 orphaned children, 7 of them were abandoned by professional and well-off parents, while only 3 of them were abandoned by poor parents; those responsible for the family home conclude that the educational and economic factor does not interfere with the moral principles and values ​​of the parents.

Prediction

Conclusions of a future event are made based on past experience.

Prediction examples  

1. Every time I go to the supermarket I forget my credit cards
2. Today i go to the supermarket
3. Today I will forget the credit cards.

• When I go to the store for tomato sauce I find it is mayonnaise
• Today i go to the store
• Today I only buy mayonnaise.

1. My partner bought a wallet at a great price.
2. Today i buy a wallet
3. Today I buy a wallet at a very good price.

• Antonio proposed to Pilar on the beach.
• On Monday Mario and I go to the beach.
• On Monday Mario proposes to me.

1. In Juan's family there are 5 women named Gabriela
2. Juan's girlfriend is pregnant
3. If Juan's girlfriend has a girl, her name will be Gabriela.

• I always gain weight in December
• Christmas starts in 3 days
• In 3 days or so I will start to gain weight.

1. My parents gave my brother a dog for his birthday
2. Tomorrow is my birthday.
3. Tomorrow they give me a dog.

What is the deductive method?

This method needs two or more premises to reach a conclusion. All the concepts must be clear so that the deduction of the problems reaches a certain conclusion

A deduction is generally started by the hypothesis and possibilities that make up a specific and of course logical conclusion, for example: all women are beautiful, individual Z is a woman, therefore individual Z is beautiful.

Types of deductive reasoning

To fully explain what the deductive method encompasses, we wanted to demonstrate its characteristics according to the following types:

Detachment law

A single statement is made and only one hypothesis is presented T is proposed, the conclusion F is the deduction of this argument and therefore: T to F is a statement, T is proposed and F is the deduction of the hypothesis.

Examples of the law of detachment

1. I have three pets, one that is 5 years old and one that is 8 years old, if my third pet is older than the one that is 5 years old but younger than the one that is 8, then my third pet is 7 years old.
2. In my family we are 20 members, 13 of them are women, that means that the remaining 7 members are men.
3. I have to buy 65 pairs of glasses, and I have already bought 54 pairs of sunglasses, therefore, the remaining 11 I must buy for reading.
4. Marcos has a younger sister who is 23 years old and an older brother who is 25, this means that Marcos is 24 years old.
5. Andrea will invite 36 people to her birthday party, 15 of the guests are adults, therefore, 21 are children.

Syllogism law

This type of deductive method presents two possible questions that cause a third factor to be modified, forming a hypothesis through the fusion of two elements to a third, for example, if Maria has a fever she cannot go to the movies with her mother, if Maria does not She goes to the cinema, she will miss the movie, so if Maria has a fever she will miss the movie.

Examples syllogisms

1. Some spiders are poisonous
2. Poisonous animals panic me.
3. Some spiders scare me.

• I like everything that is pink
• The ham is pink
• I like ham

1. I like women with short hair
2. Andrea has short hair
3. I like Andrea

• No man can walk on water
• Manuel is a man
• Manuel can't walk on water

1. In all the stores there are blue shoes
2. In the corner store they sell shoes
3. In the corner store they sell blue shoes

• All Chanel perfumes are expensive
• Chanel launched its new perfume
• Chanel perfume is expensive.

1. All women have black hair
2. Sofia is a woman
3. Sofia has black hair.

Counter-reciprocal law

Simple, if the conclusion given about the topic or object is false, the hypothesis is false, example: If my mother is cooking fish, then there is no fish. I don't have money, so I can buy a house.

Examples the Law of the counter-reciprocal

1. If he cries he is happy, if she is sad then he is laughing.  
2. If she says that she does want to leave, she is saying no, then she has left because she said no.
3. I sleep while I'm on the train, I'm not on the train so I sleep.

Differences between the two methods

Each of the research and analysis methodologies has a reason for being. However, they have notable differences that must be analyzed by researchers who address all kinds of topics.

First, the inductive method is based on hypotheses that build a conclusion, unlike the deductive method that must be based on theories based on tangible and verifiable facts.

The inductive method enjoys the spontaneity that the subject has regarding the critical and subjective point of view and the way of perceiving certain things. It has more impact on the emotions and thoughts of the individual, serving as a sensory bridge between external images and abstract thinking.

For its part, the deductive method is based on the tangible and verifiable. Quantitative research is needed to prove a hypothesis based on different arguments.