# Concept Learning in Machine Learning | Gyan Setu

The human race is slowing down, and people want more ease in their lives. For this, we constructed machines capable of receiving directions and performing duties on our behalf.

But what if computers can think for themselves and make their judgments. It sounds dreadful!!! This is truly happening in this current period of machines and technology. These miracles are being performed by large corporations such as Google and Facebook.

Have you ever noticed how, when uploading photos to Facebook, the computer analyses faces and statistics and suggests your friend’s name for tagging, or how, when searching for flights on Google for a certain place, you start receiving emails for flight-related offers?

Most of us always wonder how machines can learn from data and predict the future based on the available information considering facts and scenarios. Today we live in an era where most of us are working globally on big data technologies with great efficiency and speed. But having a huge amount of data is not the complete solution and optimal use of data until we can find patterns out of it and use those patterns to predict future events and identify our interest-specific solutions.

## What is the definition of Learning?

On the internet, there are various meanings of Learning. “The action or process of obtaining information or ability through studying, practicing, being instructed, or experiencing something,” according to one of the most basic definitions. There are numerous categories of learning methods, just as there are various meanings of Learning.

We learn a great deal during our lives as humans. Some are based on our personal experience, while others are based on memorizing. We may split learning techniques into five categories based on this:

**Rote Learning (Memorizing):**Memorizing things without understanding the underlying principles or rationale.**Instructions (Passive Learning):**Learning from a teacher or expert.**Analogy (Experience)**: We may learn new things by applying what we’ve learned in the past.**Inductive Learning (Experience):**Formulating a generalized notion based on prior experience.**Deductive Learning:**Getting new information from old information.

Inductive Learning is the process of forming a generalized notion after viewing many examples of the concept. For instance, suppose a child is requested to write the solution 2*8=? They can memorize the answer using the rote learning approach or use inductive Learning to construct a notion to compute the outcomes using examples such as 2*1=2, 2*2=4, and so on. In this approach, the child will be able to answer questions of a similar nature utilizing the same notion.

Similarly, we may train our computer to learn from previous data and recognize whether an object is in a given category of interest.

## What is concept learning, and how does it work?

Learning may be characterized as “the problem of exploring through a preset space of candidate hypothesis for the theory that best matches the training instances” in terms of machine learning, according to Tom Michell.

The acquisition of broad concepts from previous experiences accounts for a large portion of human Learning. Humans, for example, distinguish between various cars based on specific traits specified over a vast collection of attributes. This unique collection of characteristics distinguishes the subset of automobiles in the collection of vehicles. A concept is a collection of elements that distinguishes automobiles.

## Understanding the Concept:

The set of instances, represented by X, is the list of elements over which the notion is defined. The target idea, represented by c, is the notion of action to be learned. It’s a boolean-valued function that’s defined over X and may be expressed as:

**c: X -> {0, 1}**

So, when we have a subset of the training with certain attributes of the target concept c, the learner’s issue is to estimate c from the training data.

The letter H stands for the collection of all conceivable hypotheses that a learner could explore while determining the identification of the target idea.

A learner’s objective is to create a hypothesis h that can identify all of the objects in X in such a way that:

**h(x) = c(x) for all x in X**

In this sense, there are three things that an algorithm that enables concept learning must have:

1. Details about the training (Past experiences to train our models)

2. Target Conception (Hypothesis to identify data objects)

3. Data objects themselves (For testing the models)

## The hypothesis of Inductive Learning:

The ultimate aim of concept learning, as previously stated, is to find a hypothesis ‘h’ that is identical to the target notion c over data set X, with the only knowledge about c being its value over X. As a result, our algorithm can ensure that it matches the training data the best. “Any hypothesis that approximates the target value well over a suitably large collection of training instances will likewise approximate the target value well over other unseen cases,” to put it another way.

Consider whether a person goes to the movies or not based on four binary characteristics with two potential values (true or false):

1. Is Rich -> true, false

2. Is There Any Free Time -> true or false

3. It’s a Holiday -> true or false

4. Has work pending -> true, false

We also have training data, with two data items serving as positive samples and one serving as a negative sample:

**x1**: <true, true, false, false> : **+ve**

**x2**: <true, false, false, true> :** +ve**

**x3: **<true, false, false, true> : **-ve**

## Notations for Hypotheses:

Each data object represents a notion and its associated hypotheses because it can only cover one sample, a hypothesis of <true, true, false, false>. We may add some notations to this hypothesis to make it a more general idea. We have the following notations for this task:

- ? (Represents a hypothesis that rejects all.)
- < ? , ? , ? , ? > (Accepts all)
- <true, false, ? , ? > (Accepts some)

The hypothesis will reject all data samples. Conversely, all data samples will be accepted by the hypothesis **<?, ?, ?, ? > **The ‘?’ indicates that the values of this specific attribute have no bearing on the outcome.

In this fashion, the overall number of possible hypotheses is: (3 * 3 * 3 * 3) + 1, where 3 represents the fact that each character might be true, false, or ‘?’, and one hypothesis rejects all ().

From the broadest to the most specific ranking of hypotheses:

Many machine learning methods rely on the idea of hypothesis ordering from broad to particular.

h1 = < true, true, ?, ? >

h2 = < true, ? , ? , ? >

Any occurrence classed as h1 will be categorized as h2 as well. As a result, we might conclude that h2 is more generic than h1. Using this notion, we can find a broad assumption that can be specified for the complete data set X.

### The Find-S Algorithm is used to find the most specific hypotheses.

Any occurrence classed as h1 will be categorized as h2 as well. As a result, we might conclude that h2 is more generic than h1. Using this notion, we can find a broad hypothesis that can be specified for the complete data set X.

The idea of more-general-then partial ordering can be used to identify a single hypothesis specified on X. Starting with the most particular hypothesis from H and generalizing it each time it fails to categorize a behavior modification data object as positive is one technique to achieve this.

**Step 1:** In the Find-S method, the first step is to start with the most specific hypothesis, which is represented by:

h <- <?, ?, ?, ?>

**Step 2** entails selecting the next training sample and doing step 3 on it.

**Step 3: **It entails viewing the data sample. If the sample is negative, the hypothesis remains unaltered, and we go to step 2 to select the next training sample; otherwise, we proceed to step 4.

**Step 4:** If the sample is positive and we discover that our initial hypothesis is too specific and does not apply to the current training sample, we must alter our current hypothesis. This may be accomplished using the pairwise combination (logical With operation) of the present and alternative hypotheses.

We may immediately replace our existing hypothesis with the new one if the next training sample is < true, true, false, false> and the current hypothesis is <?, ?, ?, ?>.

Suppose the next positive training sample is true, true, false, true> and the current hypothesis is true, true, false, false>. In that case, we can use a bilateral conjunctive AND with the present hypothesis and the next training sample to find a new hypothesis by inserting a ‘?’ where the conjunction result is false:

**<true, true, false, true> ? <true, true, false, false> = <true, true, false, ?>**

We may now replace our old hypothesis with a new one:

h <-<true, true, false, ?>

**Step 5:** Repeating steps 2 and 3 until we have enough training data.

**Step 6:** If no training samples are available, the present hypothesis is the one we were looking for. The final hypothesis can be used to categorize real-world items.

**Step 1.** Start with h = ?

**Step 2.** Use next input {x, c(x)}

**Step 3.** If c(x) = 0, go to step 2

**Step 4.** h <- h ? x (Pairwise AND)

**Step 5.** If more examples : Go to step 2

**Step 6.** Stop

### The Find-S algorithm has certain limitations:

The Find-S method for idea learning is among the most fundamental machine learning algorithms. However, it has certain limitations and drawbacks. The following are a few of them:

- There is no way to tell if the lone final hypothesis (discovered by Find-S) is compatible with the data or if there are other hypotheses.
- Because the discovers algorithm excludes negative data samples, inconsistent sets of training images might mislead it. Thus an algorithm that can identify inconsistency in training data would be preferable.
- An excellent concept The learning algorithm will be able to reverse the hypothesis selection process so that the final hypothesis can be improved over the years. Unfortunately, Find-S does not have such a feature.

Data Science, Artificial Intelligence and Machine Learning, and Programming in various languages are taught in many coaching centers in Delhi.

Some of them are mentioned below:

- SIIT- Computer Institut in India
- Gyan Setu, Delhi
- AnalytixLabs Noida Institute
- JEETECH Academy
- IICS (INDIAN INSTITUTE OF COMPUTER SCIENCE)

Many constraints may be overcome using the Candidate Elimination Algorithm, one of the most significant idea learning algorithms.

## Frequently asked questions?

### 1.What are hypothesis and concept learning?

Learning a generic category’s description using positive and negative training examples is known as concept learning. Finding the hypothesis that best matches the training examples requires searching through a preset space of candidate hypotheses.

### 2. What does machine learning’s target notion mean?

In machine learning, a target function is a solution to a problem that an AI algorithm finds by analyzing its training data. Once an algorithm locates its target function, it may use it to forecast outcomes (predictive analysis).

### 3. What is learning supervised and unsupervised learning?

Unsupervised learning algorithm does not employ labelled input and output data. Supervised learning does. When using supervised learning, the algorithm iteratively predicts the data and modifies for the proper response to “learn” from the training dataset.

### 4. What distinguishes classification from clustering?

Although there are some similarities between the two procedures, clustering discovers commonalities between items, which it groups according to those in common and which separate them from others, whereas classification employs predetermined classes to which objects are given.

### 5. What does machine learning regression mean?

Regression is a method for determining how independent traits or variables relate to a dependent feature or result. It is a technique for machine learning predictive modeling, where an algorithm is used to forecast continuous outcomes.