Machine Learning Concepts Quiz

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

In which scenario would KNN be most appropriate to use?

  • In cases where irrelevant features can significantly affect accuracy
  • When the data has thousands of features and limited training data
  • For classification problems with manageable features (correct)
  • When rapid classification response times are required

What characterizes a leaf node in a decision tree?

  • A test on an attribute
  • The root node from which all branches extend
  • The outcome of a test on training examples
  • A class label or class label distribution (correct)

What is a disadvantage of KNN?

  • It lacks a straightforward implementation
  • It requires extensive training time
  • It is prone to overfitting with large datasets
  • It can be slow at query time or classification (correct)

Which statement about decision trees is true?

<p>The ID3 algorithm is commonly used to create decision trees (D)</p> Signup and view all the answers

What is an important step in training a decision tree?

<p>Creating an experience table with historical data (D)</p> Signup and view all the answers

What distinguishes supervised learning from unsupervised learning?

<p>Supervised learning requires guidance or labeled data. (C)</p> Signup and view all the answers

Which of the following algorithms is NOT typically associated with supervised learning?

<p>Clustering Algorithm (C)</p> Signup and view all the answers

In the context of machine learning, what does it mean for a model to 'learn from the past'?

<p>The model analyzes historical data to make predictions. (C)</p> Signup and view all the answers

What is a key characteristic of reinforcement learning compared to supervised and unsupervised learning?

<p>Reinforcement learning learns through rewards and punishments. (C)</p> Signup and view all the answers

What role does the training dataset play in supervised learning?

<p>It is the foundational basis for training the machine. (D)</p> Signup and view all the answers

Which of the following best defines machine learning?

<p>The application of AI that allows systems to learn without being specifically programmed. (C)</p> Signup and view all the answers

What is the primary objective of using supervised learning algorithms in practical applications?

<p>To classify and make predictions based on new data. (A)</p> Signup and view all the answers

What approach does unsupervised learning primarily use?

<p>Identifying relationships by clustering unlabelled data. (D)</p> Signup and view all the answers

What is the purpose of a goodness function in decision tree classification?

<p>To evaluate the splitting attributes (A)</p> Signup and view all the answers

What is the effect of bottom-up tree pruning in decision tree classification?

<p>It helps in reducing overfitting (C)</p> Signup and view all the answers

Which attribute was used first in the decision tree based on the test case provided?

<p>Outlook (A)</p> Signup and view all the answers

In which scenario will the decision tree classify the outcome as 'No' based on the given structure?

<p>Overcast, hot, normal, false (D)</p> Signup and view all the answers

What does partitioning the examples recursively in decision tree construction achieve?

<p>Allows for better class separation (D)</p> Signup and view all the answers

Which of the following represents a case where the decision tree would suggest playing?

<p>Sunny, hot, normal, true (D)</p> Signup and view all the answers

Which method is typically used in decision trees to evaluate available attributes?

<p>Goodness functions (B)</p> Signup and view all the answers

How do training examples initially start during decision tree construction?

<p>All examples are placed at the root (C)</p> Signup and view all the answers

What outcome occurs when the weather is sunny and the humidity is high, according to the decision tree?

<p>James will not play tennis. (D)</p> Signup and view all the answers

What does each internal node in the decision tree represent?

<p>An attribute being tested. (B)</p> Signup and view all the answers

In the provided dataset, under what condition will James definitely play tennis?

<p>When overcast with mild temperature. (B)</p> Signup and view all the answers

What is indicated by a leaf node in the decision tree?

<p>A yes or no prediction is made. (A)</p> Signup and view all the answers

What is the classification when the outlook is rainy, temperature is mild, and humidity is normal?

<p>James will play tennis. (D)</p> Signup and view all the answers

Which combination of conditions leads to the conclusion that James will not play tennis?

<p>Sunny, high humidity. (C)</p> Signup and view all the answers

What does the attribute 'Windy' contribute to the decision-making process?

<p>It can influence whether James plays tennis under certain conditions. (C)</p> Signup and view all the answers

What is the role of the 'Humidity' attribute in predicting if James will play tennis?

<p>It helps differentiate between playing and not playing. (B)</p> Signup and view all the answers

What fundamental method does reinforcement learning primarily utilize to improve its performance?

<p>Trial-and-error (C)</p> Signup and view all the answers

Which type of data is used in supervised learning?

<p>Labelled data (C)</p> Signup and view all the answers

In reinforcement learning, what does the agent primarily discover from its interactions with the environment?

<p>Errors or rewards based on actions (D)</p> Signup and view all the answers

Which type of machine learning does not require any pre-defined data?

<p>Unsupervised Learning (C)</p> Signup and view all the answers

What is a common application problem solved by supervised learning?

<p>Classification or regression (C)</p> Signup and view all the answers

What key aspect distinguishes reinforcement learning from the other types of machine learning?

<p>Relies on an agent interacting with the environment (C)</p> Signup and view all the answers

How does an agent in reinforcement learning receive feedback?

<p>From errors or rewards for actions (A)</p> Signup and view all the answers

What defines the approach of reinforcement learning?

<p>Following a trial-and-error method (C)</p> Signup and view all the answers

Which type of learning involves no supervision?

<p>Reinforcement Learning (A)</p> Signup and view all the answers

What primary goal does unsupervised learning achieve?

<p>Understand patterns and discover output (B)</p> Signup and view all the answers

What does the information gain measure in decision trees?

<p>The decrease in entropy after a split (A)</p> Signup and view all the answers

What is NOT a part of calculating the information gain?

<p>Finding the average of the values in the dataset (D)</p> Signup and view all the answers

Which attribute had the highest information gain based on the content?

<p>Outlook (D)</p> Signup and view all the answers

How is the entropy of a subset calculated based on the given information?

<p>Using the formula -p+ log2 p+ - p- log2 p- (D)</p> Signup and view all the answers

In calculating expected information for attribute subsets, which aspect is considered?

<p>The weighted average of entropy across subsets (C)</p> Signup and view all the answers

Entropy value can only be zero if:

<p>All outcomes are the same (B)</p> Signup and view all the answers

What attribute showed the least information gain?

<p>Temperature (D)</p> Signup and view all the answers

Why can’t we use a simple average for information gain calculations?

<p>It does not account for the size of subsets (B)</p> Signup and view all the answers

What does high entropy indicate about a subset?

<p>High uncertainty in classification (B)</p> Signup and view all the answers

How do you determine the expected information for the attribute subsets?

<p>Using the weighted sum of each subset's entropy (D)</p> Signup and view all the answers

What effect does a larger entropy value in a subset have on information gain?

<p>Decreases information gain (D)</p> Signup and view all the answers

Entropy is often expressed mathematically according to which formula?

<p>E = -∑ p log(p) (B)</p> Signup and view all the answers

When calculating the information gain, why is the formula structured as Entropy(S) - ∑ E(Sv)?

<p>To evaluate the reduction in uncertainty from the original set (D)</p> Signup and view all the answers

Flashcards

Machine Learning

A science where computers learn without explicit programming, improving with experience.

Supervised Learning

Machine learning with labeled data; the machine learns under guidance like a student with a teacher.

Unsupervised Learning

Machine learning with unlabeled data; the machine finds patterns and structures without a teacher.

Training Dataset

The dataset used to train the machine learning model.

Signup and view all the flashcards

Labeled Data

Data with associated categories or labels.

Signup and view all the flashcards

Unlabeled Data

Data without categories or labels.

Signup and view all the flashcards

K Nearest Neighbors (KNN)

A supervised learning algorithm that classifies data based on nearest neighbors.

Signup and view all the flashcards

Decision Tree

A supervised learning algorithm that uses a tree-like model to make decisions from data.

Signup and view all the flashcards

KNN Use Cases

KNN is useful for classification problems with manageable features (less than 20) and plenty of training data.

Signup and view all the flashcards

KNN Advantages

KNN has no training period, is easy to implement, and new data integrates smoothly.

Signup and view all the flashcards

KNN Disadvantages

KNN slows down with many queries and is vulnerable to misleading features.

Signup and view all the flashcards

Decision Tree Structure

Decision trees start with a root node and branch downward in a tree structure, splitting data based on attributes until reaching a leaf node with a prediction (class label).

Signup and view all the flashcards

Decision Tree Training

Decision Tree training involves choosing relevant attributes, creating a table of past experiences showing target attributes and building a decision tree via an algorithm, like ID3, to progressively sort data into classes.

Signup and view all the flashcards

Reinforcement Learning

A type of machine learning where an agent learns by interacting with an environment, taking actions, and receiving rewards or penalties.

Signup and view all the flashcards

Supervised Learning

A machine learning method where the algorithm is trained on labelled data, mapping inputs to known outputs.

Signup and view all the flashcards

Unsupervised Learning

A machine learning method used to identify patterns and structure in unlabeled data without pre-defined outputs.

Signup and view all the flashcards

Labeled Data

Data with known output values or labels, used to train supervised learning algorithms.

Signup and view all the flashcards

Unlabeled Data

Data without pre-defined output values or labels used for unsupervised learning.

Signup and view all the flashcards

Trial and Error

A learning method where an agent tries different actions and learns from the consequences (rewards or penalties)

Signup and view all the flashcards

Classification

A supervised learning problem type where the algorithm classifies inputs to predefined classes.

Signup and view all the flashcards

Clustering

An unsupervised learning problem type where data is grouped into clusters based on similarities.

Signup and view all the flashcards

Regression

A supervised learning problem type where the algorithm predicts a continuous output value.

Signup and view all the flashcards

Association Rule Learning

A subfield of unsupervised learning that finds relationships or rules between variables in databases.

Signup and view all the flashcards

Decision Tree

A supervised learning algorithm that uses a tree-like structure to make decisions based on data.

Signup and view all the flashcards

Internal Node

A node in a decision tree that tests an attribute (feature) of the data.

Signup and view all the flashcards

Attribute

A characteristic or feature of the data being analyzed.

Signup and view all the flashcards

Leaf Node

A node in a decision tree that holds a decision or class (e.g., YES/NO).

Signup and view all the flashcards

Outlook

In the example, weather condition (e.g., sunny, overcast, rain).

Signup and view all the flashcards

Humidity

The amount of water vapor in the air used for decision making.

Signup and view all the flashcards

Play?

The decision variable in the example (play tennis or not).

Signup and view all the flashcards

Supervised Learning

Machine learning with labeled data, where the algorithm learns from provided examples.

Signup and view all the flashcards

Decision Tree Classification

A supervised learning method that uses a tree-like structure to classify data based on attributes.

Signup and view all the flashcards

Splitting Attribute

The attribute chosen to create different branches in the decision tree, separating the data based on a certain condition.

Signup and view all the flashcards

Goodness Function

A function used to evaluate the quality of a splitting attribute in a decision tree.

Signup and view all the flashcards

Information Gain

A goodness function used in decision tree algorithms to select the best attribute to split on, based on reducing uncertainty about the target variable.

Signup and view all the flashcards

Top-Down Tree Construction

Building a decision tree by recursively partitioning the training data based on attributes.

Signup and view all the flashcards

Bottom-Up Tree Pruning

Removing parts of a decision tree to increase accuracy on unseen data.

Signup and view all the flashcards

Example of Test Case

Input data used to evaluate the decision tree's prediction on new occurrences.

Signup and view all the flashcards

Attribute Evaluation

Process of assessing attributes to determine the best one for splitting data in a decision tree, typically done using a goodness function.

Signup and view all the flashcards

Information Gain

Difference in entropy before and after a split in a dataset.

Signup and view all the flashcards

Entropy

Measure of uncertainty in a dataset.

Signup and view all the flashcards

Attribute Subset

Portion of dataset where a specific attribute has a particular value.

Signup and view all the flashcards

Weighted Average

Average considering different values for each dataset subset by their size.

Signup and view all the flashcards

Entropy Formula

Used to calculate entropy (-probability*log2(probability)).

Signup and view all the flashcards

Outlook Attribute

Categorical attribute in the decision tree dataset.

Signup and view all the flashcards

Gain(S, Outlook)

Information gain from using Outlook to split the dataset.

Signup and view all the flashcards

Gain(S, Temperature)

Information gain from using Temperature to split the dataset.

Signup and view all the flashcards

Gain(S, Humidity)

Information gain from using Humidity to split the dataset.

Signup and view all the flashcards

Gain(S, Windy)

Information gain from using Windy to split the dataset.

Signup and view all the flashcards

Root Node

Starting point of the decision tree.

Signup and view all the flashcards

Decision Tree

A tree-like model for making decisions based on data.

Signup and view all the flashcards

Leaf Node

Final part of the decision tree; prediction made here.

Signup and view all the flashcards

Splitting Criteria

The rules used to divide dataset subsets.

Signup and view all the flashcards

Related Documents

More Like This

KNN Classification Algorithm Example
10 questions
Machine Learning: KNN e LDA
47 questions

Machine Learning: KNN e LDA

SelfSufficiencySchrodinger avatar
SelfSufficiencySchrodinger
Use Quizgecko on...
Browser
Browser