_id
stringlengths
2
6
text
stringlengths
3
395
title
stringclasses
1 value
C4900
Structural risk minimization (SRM) is an inductive principle of use in machine learning. The SRM principle addresses this problem by balancing the model's complexity against its success at fitting the training data.
C4901
Classification is a supervised machine learning approach, in which the algorithm learns from the data input provided to it — and then uses this learning to classify new observations. The name ("Naive") derives from the fact that the algorithm assumes that attributes are conditionally independent.
C4902
Conviction compares the probability that X appears without Y if they were dependent with the actual frequency of the appearance of X without Y.
C4903
Advantages of Systematic SamplingEasy to Execute and Understand.Control and Sense of Process.Clustered Selection Eliminated.Low Risk Factor.Assumes Size of Population Can Be Determined.Need for Natural Degree of Randomness.Greater Risk of Data Manipulation.
C4904
In the context of conventional artificial neural networks convergence describes a progression towards a network state where the network has learned to properly respond to a set of training patterns within some margin of error.
C4905
“The decision of whether to use a one‐ or a two‐tailed test is important because a test statistic that falls in the region of rejection in a one‐tailed test may not do so in a two‐tailed test, even though both tests use the same probability level.”
C4906
Entropy, the measure of a system's thermal energy per unit temperature that is unavailable for doing useful work. Because work is obtained from ordered molecular motion, the amount of entropy is also a measure of the molecular disorder, or randomness, of a system.
C4907
Poisson regression is used to predict a dependent variable that consists of "count data" given one or more independent variables. The variable we want to predict is called the dependent variable (or sometimes the response, outcome, target or criterion variable).
C4908
It should not be less than 60%. If the variance explained is 35%, it shows the data is not useful, and may need to revisit measures, and even the data collection process. If the variance explained is less than 60%, there are most likely chances of more factors showing up than the expected factors in a model.
C4909
Histograms, 3D Bivariate. Three-dimensional histograms are used to visualize crosstabulations of values in two variables. They can be considered to be a conjunction of two simple (i.e., univariate) histograms, combined such that the frequencies of co-occurrences of values on the two analyzed variables can be examined.
C4910
The subject of this chapter is image key points which we define as a distinctive point in an input image which is invariant to rotation, scale and distortion.
C4911
Major: Mathematics and Statistics. Programs called “mathematics and statistics” either combine the study of math and statistics or focus on a specialization that uses both math and statistics. Topics of study include calculus, algebra, differential equations, probability theory, and computing.
C4912
To recap, we have covered some of the the most important machine learning algorithms for data science: 5 supervised learning techniques- Linear Regression, Logistic Regression, CART, Naïve Bayes, KNN. 3 unsupervised learning techniques- Apriori, K-means, PCA.
C4913
Structural information theory (SIT) is a theory about human perception and in particular about visual perceptual organization, which is the neuro-cognitive process that enables us to perceive scenes as structured wholes consisting of objects arranged in space.
C4914
You tend to take logs of the data when there is a problem with the residuals. For example, if you plot the residuals against a particular covariate and observe an increasing/decreasing pattern (a funnel shape), then a transformation may be appropriate.
C4915
This process occurs over and over as the weights are continually tweaked. The set of data which enables the training is called the "training set." During the training of a network the same set of data is processed many times as the connection weights are ever refined.
C4916
The two major types of bias are:Selection Bias.Information Bias.
C4917
GloVe is an unsupervised learning algorithm for obtaining vector representations for words. Training is performed on aggregated global word-word co-occurrence statistics from a corpus, and the resulting representations showcase interesting linear substructures of the word vector space.
C4918
So that we only have to have one area table, rather than an infinite number of area tables. Of course, technology can find area under any normal curve and so tables of values are a bit archaic.
C4919
1 Answer. In word2vec, you train to find word vectors and then run similarity queries between words. In doc2vec, you tag your text and you also get tag vectors. If two authors generally use the same words then their vector will be closer.
C4920
demean() is intended to create group- and de-meaned variables for panel regression models (fixed effects models), or for complex random-effect-within-between models (see Bell et al. 2015, 2018 ), where group-effects (random effects) and fixed effects correlate (see Bafumi and Gelman 2006 ).
C4921
Definition. Stimulus generalization is the tendency of a new stimulus to evoke responses or behaviors similar to those elicited by another stimulus. For example, Ivan Pavlov conditioned dogs to salivate using the sound of a bell and food powder.
C4922
Bayesian search theory is the application of Bayesian statistics to the search for lost objects. It has been used several times to find lost sea vessels, for example the USS Scorpion, and has played a key role in the recovery of the flight recorders in the Air France Flight 447 disaster of 2009.
C4923
A confidence interval, in statistics, refers to the probability that a population parameter will fall between a set of values for a certain proportion of times. Confidence intervals measure the degree of uncertainty or certainty in a sampling method.
C4924
Recursive and Nonrecursive Discrete-Time Systems This is a recursive system which means the output at time n depends on any number of a past output values. So, a recursive system has feed back output of the system into the input.
C4925
Disparate impact lawsuits claim that an employer's facially neutral practice had a discriminatory effect. Disparate impact is a way to prove employment discrimination based on the effect of an employment policy or practice rather than the intent behind it.
C4926
Hidden Markov Model (HMM) is a statistical Markov model in which the system being modeled is assumed to be a Markov process – call it – with unobservable ("hidden") states. HMM assumes that there is another process whose behavior "depends" on . The goal is to learn about by observing .
C4927
As explained above, the shape of the t-distribution is affected by sample size. As the sample size increases, so do degrees of freedom. When degrees of freedom are infinite, the t-distribution is identical to the normal distribution. As sample size increases, the sample more closely approximates the population.
C4928
A p-value less than 0.05 (typically ≤ 0.05) is statistically significant. It indicates strong evidence against the null hypothesis, as there is less than a 5% probability the null is correct (and the results are random). Therefore, we reject the null hypothesis, and accept the alternative hypothesis.
C4929
In data mining, anomaly detection is referred to the identification of items or events that do not conform to an expected pattern or to other items present in a dataset. Machine learning algorithms have the ability to learn from data and make predictions based on that data.
C4930
Draw a boxplot of your data. If your data comes from a normal distribution, the box will be symmetrical with the mean and median in the center. If the data meets the assumption of normality, there should also be few outliers. A normal probability plot showing data that's approximately normal.
C4931
A continuity correction factor is used when you use a continuous probability distribution to approximate a discrete probability distribution. For example, when you want to use the normal to approximate a binomial. p = probability of an event (e.g. 60%), q = probability the event doesn't happen (100% – p).
C4932
In the context of a local search, we call local beam search a specific algorithm that begins selecting randomly generated states and then, for each level of the search tree, it always considers. new states among all the possible successors of the current ones, until it reaches a goal.
C4933
In a hypothesis test, we:Evaluate the null hypothesis, typically denoted with H0. Always write the alternative hypothesis, typically denoted with Ha or H1, using less than, greater than, or not equals symbols, i.e., (≠, >, or <).More items
C4934
The Dissimilarity matrix is a matrix that expresses the similarity pair to pair between two sets. It's square and symmetric. The diagonal members are defined as zero, meaning that zero is the measure of dissimilarity between an element and itself.
C4935
The normal distribution is a probability distribution. It is also called Gaussian distribution because it was first discovered by Carl Friedrich Gauss. It is often called the bell curve, because the graph of its probability density looks like a bell. Many values follow a normal distribution.
C4936
Bias is a disproportionate weight in favor of or against an idea or thing, usually in a way that is closed-minded, prejudicial, or unfair. Biases can be innate or learned. People may develop biases for or against an individual, a group, or a belief. In science and engineering, a bias is a systematic error.
C4937
Dimensionality reduction refers to techniques for reducing the number of input variables in training data. When dealing with high dimensional data, it is often useful to reduce the dimensionality by projecting the data to a lower dimensional subspace which captures the “essence” of the data.
C4938
An artificial neuron (also referred to as a perceptron) is a mathematical function. It takes one or more inputs that are multiplied by values called “weights” and added together. This value is then passed to a non-linear function, known as an activation function, to become the neuron's output.
C4939
A Markov process is a random process in which the future is independent of the past, given the present. Thus, Markov processes are the natural stochastic analogs of the deterministic processes described by differential and difference equations. They form one of the most important classes of random processes.
C4940
Vector autoregression (VAR) is a statistical model used to capture the relationship between multiple quantities as they change over time. This equation includes the variable's lagged (past) values, the lagged values of the other variables in the model, and an error term.
C4941
Normal distribution describes continuous data which have a symmetric distribution, with a characteristic 'bell' shape. Binomial distribution describes the distribution of binary data from a finite sample. Thus it gives the probability of getting r events out of n trials.
C4942
The range can only tell you basic details about the spread of a set of data. By giving the difference between the lowest and highest scores of a set of data it gives a rough idea of how widely spread out the most extreme observations are, but gives no information as to where any of the other data points lie.
C4943
The term normal score is used with two different meanings in statistics. A given data point is assigned a value which is either exactly, or an approximation, to the expectation of the order statistic of the same rank in a sample of standard normal random variables of the same size as the observed data set.
C4944
Lift is a measure of the effectiveness of a predictive model calculated as the ratio between the results obtained with and without the predictive model. Cumulative gains and lift charts are visual aids for measuring model performance.
C4945
Summary: Population variance refers to the value of variance that is calculated from population data, and sample variance is the variance calculated from sample data. Due to this value of denominator in the formula for variance in case of sample data is 'n-1', and it is 'n' for population data.
C4946
PIT is a state of the art mutation testing system, providing gold standard test coverage for Java and the jvm. It's fast, scalable and integrates with modern test and build tooling.
C4947
Unsupervised learning uses the entire dataset for the supervised training process. In contrast, in self-supervised learning, you withhold part of the data in some form, and you try to predict the rest. In contrast, in self-supervised learning, you withhold part of the data in some form, and you try to predict the rest.
C4948
Regression Techniques Regression algorithms are machine learning techniques for predicting continuous numerical values.
C4949
Multi-agent reinforcement learning is the study of numerous artificial intelligence agents cohabitating in an environment, often collaborating toward some end goal. When focusing on collaboration, it derives inspiration from other social structures in the animal kingdom. It also draws heavily on game theory.
C4950
The value of the z-score tells you how many standard deviations you are away from the mean. A positive z-score indicates the raw score is higher than the mean average. For example, if a z-score is equal to +1, it is 1 standard deviation above the mean. A negative z-score reveals the raw score is below the mean average.
C4951
(1 p)xp = (1 p)a+1p + ··· + (1 p)bp = (1 p)a+1p (1 p)b+1p 1 (1 p) = (1 p)a+1 (1 p)b+1 We can take a = 0 to find the distribution function for a geometric random variable. The initial d indicates density and p indicates the probability from the distribution function.
C4952
Acceptance sampling is a quality control procedure, which uses the inspection of small samples instead of 100 percent inspection in making the decision to accept or reject much larger quantities, called a lot.
C4953
In statistics, the likelihood function (often simply called the likelihood) measures the goodness of fit of a statistical model to a sample of data for given values of the unknown parameters. But in both frequentist and Bayesian statistics, the likelihood function plays a fundamental role.
C4954
The main difference between inductive and deductive reasoning is that inductive reasoning aims at developing a theory while deductive reasoning aims at testing an existing theory. Inductive reasoning moves from specific observations to broad generalizations, and deductive reasoning the other way around.
C4955
Eigenfunctions are those functions that satisfy eigenvalue equations. In quantum physics we say that because an eigenvalue equation is linear, then all linear combinations of its solutions are also solutions.
C4956
robust is a programmer's command that computes a robust variance estimator based on a varlist of equation-level scores and a covariance matrix.
C4957
From the perspective of algorithm steps, the difference is when computing the center of each cluster, K-center method will take the average(mean) of samples in each cluster. While K-median method choose to take the median of samples instead of mean. K-medians is robust to outliers and results in compact clusters.
C4958
Moment generating functions are a way to find moments like the mean(μ) and the variance(σ2). They are an alternative way to represent a probability distribution with a simple one-variable function.
C4959
Definition: The range of a random variable is the smallest interval that contains all the values of the random variable. A variation of the last definition says that the range of a random variable is the smallest interval that contains all the values of the random variable with probability 1.
C4960
A Fourier transform is holographic because all points in the input affect a single point in the output and vice versa. The neural nets in organic brains have been considered holographic because skills and memories seem to be spread out over many different neurons.
C4961
1:2013:53Suggested clip · 97 secondsThe Binomial Distribution: Mathematically Deriving the Mean and YouTubeStart of suggested clipEnd of suggested clip
C4962
Squaring the residuals, averaging the squares, and taking the square root gives us the r.m.s error. You then use the r.m.s. error as a measure of the spread of the y values about the predicted y value.
C4963
The p-value is calculated using the sampling distribution of the test statistic under the null hypothesis, the sample data, and the type of test being done (lower-tailed test, upper-tailed test, or two-sided test). a lower-tailed test is specified by: p-value = P(TS ts | H 0 is true) = cdf(ts)
C4964
Multiclass classification with logistic regression can be done either through the one-vs-rest scheme in which for each class a binary classification problem of data belonging or not to that class is done, or changing the loss function to cross- entropy loss. By default, multi_class is set to 'ovr'.
C4965
0:254:04Suggested clip · 117 secondsProbability density functions - Finding the constant k (example to try YouTubeStart of suggested clipEnd of suggested clip
C4966
CNN Architectures: LeNet, AlexNet, VGG, GoogLeNet, ResNet and more… A Convolutional Neural Network (CNN, or ConvNet) are a special kind of multi-layer neural networks, designed to recognize visual patterns directly from pixel images with minimal preprocessing..
C4967
In machine learning and pattern recognition, a feature is an individual measurable property or characteristic of a phenomenon being observed. Choosing informative, discriminating and independent features is a crucial step for effective algorithms in pattern recognition, classification and regression.
C4968
Physical scientists often use the term root-mean-square as a synonym for standard deviation when they refer to the square root of the mean squared deviation of a signal from a given baseline or fit.
C4969
sigmoid activation function
C4970
Cluster sampling is a probability sampling method in which you divide a population into clusters, such as districts or schools, and then randomly select some of these clusters as your sample. The clusters should ideally each be mini-representations of the population as a whole.
C4971
The Gini coefficient for the entire world has been estimated by various parties to be between 0.61 and 0.68.
C4972
An XOR (exclusive OR gate) is a digital logic gate that gives a true output only when both its inputs differ from each other. The truth table for an XOR gate is shown below: Truth Table for XOR. The goal of the neural network is to classify the input patterns according to the above truth table.
C4973
Neural networks generally perform supervised learning tasks, building knowledge from data sets where the right answer is provided in advance. The networks then learn by tuning themselves to find the right answer on their own, increasing the accuracy of their predictions.
C4974
Consequences of Heteroscedasticity The OLS estimators and regression predictions based on them remains unbiased and consistent. The OLS estimators are no longer the BLUE (Best Linear Unbiased Estimators) because they are no longer efficient, so the regression predictions will be inefficient too.
C4975
An expert system is an example of a knowledge-based system. Expert systems were the first commercial systems to use a knowledge-based architecture. A knowledge-based system is essentially composed of two sub-systems: the knowledge base and the inference engine. The knowledge base represents facts about the world.
C4976
Using a confidence interval is a better way of conveying this information since it keeps the emphasis on the effect size - which is the important information - rather than the p-value. (Where NE and NC are the numbers in the experimental and control groups, respectively.)
C4977
2:194:05Suggested clip · 97 secondsChoosing Intervals for a Histogram - YouTubeYouTubeStart of suggested clipEnd of suggested clip
C4978
Definition. Univariate analyses are used extensively in quality of life research. Univariate analysis is defined as analysis carried out on only one (“uni”) variable (“variate”) to summarize or describe the variable (Babbie, 2007; Trochim, 2006).
C4979
Types of machine learning AlgorithmsSupervised learning.Unsupervised Learning.Semi-supervised Learning.Reinforcement Learning.
C4980
Statistics is the study of the collection, organization, analysis, and interpretation of data. Mathematical statistics is the study of statistics from a mathematical standpoint, using probability theory as well as other branches of mathematics such as linear algebra and analysis.
C4981
To calculate permutations, we use the equation nPr, where n is the total number of choices and r is the amount of items being selected. To solve this equation, use the equation nPr = n! / (n - r)!.
C4982
When you conduct a study that looks at a single variable, that study involves univariate data. For example, you might study a group of college students to find out their average SAT scores or you might study a group of diabetic patients to find their weights. Bivariate data is when you are studying two variables.
C4983
Terms in this set (35) The main difference between a z-score and t-test is that the z-score assumes you do/don't know the actual value for the population standard deviation, whereas the t-test assumes you do/don't know the actual value for the population standard deviation.
C4984
Probability Density Functions are a statistical measure used to gauge the likely outcome of a discrete value, e.g., the price of a stock or ETF. PDFs are plotted on a graph typically resembling a bell curve, with the probability of the outcomes lying below the curve.
C4985
The other assumption of one-way anova is that the variation within the groups is equal (homoscedasticity). While Kruskal-Wallis does not assume that the data are normal, it does assume that the different groups have the same distribution, and groups with different standard deviations have different distributions.
C4986
In probability theory and statistics, the gamma distribution is a two-parameter family of continuous probability distributions. The exponential distribution, Erlang distribution, and chi-squared distribution are special cases of the gamma distribution.
C4987
2 Answers. Simply put because one level of your categorical feature (here location) become the reference group during dummy encoding for regression and is redundant. I am quoting form here "A categorical variable of K categories, or levels, usually enters a regression as a sequence of K-1 dummy variables.
C4988
Gated recurrent units (GRUs) are a gating mechanism in recurrent neural networks, introduced in 2014 by Kyunghyun Cho et al. The GRU is like a long short-term memory (LSTM) with a forget gate, but has fewer parameters than LSTM, as it lacks an output gate.
C4989
For a statistical test to be valid, your sample size needs to be large enough to approximate the true distribution of the population being studied. To determine which statistical test to use, you need to know: whether your data meets certain assumptions. the types of variables that you're dealing with.
C4990
Seven Techniques for Data Dimensionality ReductionMissing Values Ratio. Data columns with too many missing values are unlikely to carry much useful information. Low Variance Filter. High Correlation Filter. Random Forests / Ensemble Trees. Principal Component Analysis (PCA). Backward Feature Elimination. Forward Feature Construction.
C4991
Mentor: Well, if the line is a good fit for the data then the residual plot will be random. However, if the line is a bad fit for the data then the plot of the residuals will have a pattern.
C4992
Run regression analysisOn the Data tab, in the Analysis group, click the Data Analysis button.Select Regression and click OK.In the Regression dialog box, configure the following settings: Select the Input Y Range, which is your dependent variable. Click OK and observe the regression analysis output created by Excel.
C4993
: one half of the difference obtained by subtracting the first quartile from the third quartile in a frequency distribution.
C4994
The bivariate Pearson correlation indicates the following: Whether a statistically significant linear relationship exists between two continuous variables. The strength of a linear relationship (i.e., how close the relationship is to being a perfectly straight line)5 days ago
C4995
Contents. In image processing filters are mainly used to suppress either the high frequencies in the image, i.e. smoothing the image, or the low frequencies, i.e. enhancing or detecting edges in the image. An image can be filtered either in the frequency or in the spatial domain.
C4996
Other examples of active learning techniques include role-playing, case studies, group projects, think-pair-share, peer teaching, debates, Just-in-Time Teaching, and short demonstrations followed by class discussion. There are two easy ways to promote active learning through the discussion.
C4997
In a supervised learning model, the algorithm learns on a labeled dataset, providing an answer key that the algorithm can use to evaluate its accuracy on training data. An unsupervised model, in contrast, provides unlabeled data that the algorithm tries to make sense of by extracting features and patterns on its own.
C4998
Correlation coefficients are used to measure the strength of the relationship between two variables. This measures the strength and direction of a linear relationship between two variables. Values always range between -1 (strong negative relationship) and +1 (strong positive relationship).
C4999
A recurrent neural network (RNN) is a type of artificial neural network commonly used in speech recognition and natural language processing (NLP). RNNs are designed to recognize a data's sequential characteristics and use patterns to predict the next likely scenario.