Dropout: A Simple Way to Prevent Neural Networks from Overfitting — TEI-tagged view

Nitish Srivastava, Geoffrey Hinton, Alex Krizhevsky, Ilya Sutskever, Ruslan Salakhutdinov · 2014 · artificial-intelligence · source · full text at the source · TEI xml · tagged edition · index · concepts · authors
Where this record's text came from. faceted 2026-08 by reading the locally held text (pdftext); every evidence string verified as an exact substring of that text before merging. Extraction is clean apart from figure-axis text and inline math fragments; all quotes are from running prose. Claim type is 'method' because the contribution is the training technique itself, but the paper also advances a mechanistic hypothesis for why it works ('We hypothesize that for each hidden unit, dropout prevents co-adaptation by making the presence of other hidden units unreliable.'), which the single-valued facet cannot hold alongside the method claim. Method label is 'computational-experiment' - benchmark training runs across seven data sets - since none of the suggested labels fits a machine-learning empirical evaluation. Only one claim_relation is recorded: the related-work section mentions van der Maaten et al. (2013), Wang and Manning (2013), Chen et al. (2012), Globerson and Roweis (2006) and others, but those are descriptions of neighbouring work rather than statements of how this paper stands to them, so per the rule they are left out. Replication status is 'untested' in the sense of independent replication; the paper's own repeated evaluations across data sets are internal. 2026-08-14 and 2026-08-25 schema-0.3 passes: every quote verified as an exact substring of the staged text and anchored at merge time; concept terms verified present; every edge endpoint an existing node.
Other fields define these differently the same word, defined another way in another discipline
deep learning 11 fields · overfitting 6 fields · training 3 fields · neural networks 3 fields · standard-deviation 3 fields · linear regression 2 fields
Tags on this paper every tag the record carries, whether or not the words occur in the text below — a number is how many papers in the corpus carry that tag; a tag with no number is unique to this paper
dropout6 regularization4 overfitting16 neural network6 geometric mean5 sexual reproduction thinned model combination system-or-tool-building173
Method, as described: computational-experiment

Our tag layer for this paper

Cross-disciplinary analysis
content-tags & facets: phenomenon · claim-type · cross-domain-transfer · mechanism · claim-relation · replication-status · limitation — grounded in the full text
phenomenonoverfitting in deep neural networks— “However, overfitting is a serious problem in such networks.”
claim-typemethod— “Dropout is a technique for addressing this problem.”
method — evidence— “We trained dropout neural networks for classification problems on data sets in different domains.”
transferfrom evolutionary biology (theory of sexual reproduction): dropout as a neural-net regularizer inspired by the evolutionary role of sex - breaking co-adaptations, analogous to genetic recombination— “A motivation for dropout comes from a theory of the role of sex in evolution”transfers[0]
mechanismrandomly drop units during training so neurons cannot co-adapt; this approximates averaging an exponential ensemble of thinned networks, regularizing the model— “The key idea is to randomly drop units (along with their connections) from the neural network during training”mechanisms[0]
extends prior regularization methods for neural networks— “This significantly reduces overfitting and gives major improvements over other regularization methods.”claim_relations[0]
extends denoising autoencoders (Vincent et al., 2008, 2010), where noise is added to the input units— “Our work extends this idea by showing that dropout can be effectively applied in the hidden layers as well and that it can be interpreted as a form of model averaging.”claim_relations[1]
sensethe motivation for dropout - AN ANALOGY, FLAGGED AS ONE: a theory of the role of sex in evolution, in which combining half of each parent's genes beats copying a good genome directly; the paper presents this as a motivation and not as a derivation, and its only proof of an equivalent regularizer is for linear regression— “A motivation for dropout comes from a theory of the role of sex in evolution (Livnat et al., 2010). Sexual reproduction involves taking half the genes of one parent and half of the other, adding a very small amount of random mutation, and combining them to produce an offspring”senses[0]
sensethe test-time network - A STAND-IN FOR AN ENSEMBLE THAT IS NEVER BUILT: a single unthinned network with scaled weights approximates an equally weighted geometric mean over an exponential number of thinned networks, so the rule everyone implements is a cheap approximation to a computation nobody performs— “We propose to do this by approximating an equally weighted geometric mean of the predictions of an exponential number of learned models that share parameters”senses[1]
sensea thinned network - ONE SAMPLE FROM 2^n: applying dropout amounts to sampling a thinned network, and a net with n units is described as a collection of that many possible thinned networks all sharing weights, so 'a dropout network' names a distribution over architectures rather than one architecture— “Applying dropout to a neural network amounts to sampling a “thinned” network from it”senses[2]
controlthe same architectures trained with and without dropout, differing only in whether a thinned network is sampled for each training case in a mini-batch — held — rules out an improvement owed to the architecture, the data or the training schedule rather than to dropout itself— “The same architectures trained with and without dropout have drastically different test errors as seen as by the two separate clusters of trajectories.”controls[0]
auditdropout —operationalised-as→ thinned — Audit 2026-09-28: DOUBTFUL - read against its full span and kept, but the span says applying dropout AMOUNTS TO sampling a 'thinned' network; operationalised-as is loose.— “Applying dropout to a neural network amounts to sampling a “thinned” network from it”concept_edges[0]
outcome (stated by the tagger, no quotation)control — heldcontrols[0]
for which uselimitation — the cost side of adopting dropout: ONE OF THE DRAWBACKS OF DROPOUT IS THAT IT INCREASES TRAINING TIME— “One of the drawbacks of dropout is that it increases training time.”limitations[0]
duplicate oflimitation — limitations[0]— “One of the drawbacks of dropout is that it increases training time.”limitations[1]
for which uselimitation — the same scope as limitations[0] - training is substantially slower— “One of the drawbacks of dropout is that it increases training time.”limitations[1]
for which uselimitation — small-data applications, where the benefit is measured at zero: FOR EXTREMELY SMALL DATA SETS (100, 500) DROPOUT DOES NOT GIVE ANY IMPROVEMENTS— “It can be observed that for extremely small data sets (100, 500) dropout does not give any improvements.”limitations[2]
for which uselimitation — text applications specifically: on Reuters THE IMPROVEMENT WAS MUCH SMALLER COMPARED TO THAT FOR THE VISION AND SPEECH DATA SETS— “We found that the improvement was much smaller compared to that for the vision and speech data sets.”limitations[3]
for which uselimitation — any theoretical account of dropout beyond linear regression: FOR MORE COMPLICATED MODELS, IT IS NOT OBVIOUS HOW TO OBTAIN AN EQUIVALENT REGULARIZER— “For more complicated models, it is not obvious how to obtain an equivalent regularizer.”limitations[4]
for which uselimitation — any account of why dropout works: the authors give as motivation a theory of the role of sex in evolution, in which reproduction combines half the genes of each parent with a small amount of random mutation— “A motivation for dropout comes from a theory of the role of sex in evolution (Livnat et al., 2010). Sexual reproduction involves taking half the genes of one parent and half of the other, adding a very small amount of random mutation, and combining them to produce an offspring”limitations[5]
for which uselimitation — any account of why dropout works: the authors offer a second motivation, described as closely related but slightly different, from thinking about successful conspiracies— “A closely related, but slightly different motivation for dropout comes from thinking about successful conspiracies”limitations[6]
for which uselimitation — the weight-scaling rule used at test time: the authors describe it as— “We propose to do this by approximating an equally weighted geometric mean of the predictions of an exponential number of learned models that share parameters”limitations[7]
replicationuntested
limitationdropout increases training time— “One of the drawbacks of dropout is that it increases training time.”limitations[0]
limitationDropout makes training substantially slower.— “One of the drawbacks of dropout is that it increases training time.”limitations[1]
limitationOn very small training sets dropout gives no benefit at all.— “It can be observed that for extremely small data sets (100, 500) dropout does not give any improvements.”limitations[2]
limitationThe gain on the Reuters text data set was far smaller than on vision and speech data.— “We found that the improvement was much smaller compared to that for the vision and speech data sets.”limitations[3]
limitationThe equivalent deterministic regularizer is only derived for linear regression; for richer models it is unknown.— “For more complicated models, it is not obvious how to obtain an equivalent regularizer.”limitations[4]
limitationThe method's stated motivation is an analogy to sexual reproduction, not a derivation.— “A motivation for dropout comes from a theory of the role of sex in evolution (Livnat et al., 2010). Sexual reproduction involves taking half the genes of one parent and half of the other, adding a very small amount of random mutation, and combining them to produce an offspring”limitations[5]
limitationA second, separate motivation is offered by analogy to conspiracies.— “A closely related, but slightly different motivation for dropout comes from thinking about successful conspiracies”limitations[6]
limitationThe test-time procedure is an approximation to averaging an exponential number of networks.— “We propose to do this by approximating an equally weighted geometric mean of the predictions of an exponential number of learned models that share parameters”limitations[7]
Content tags
content-observations: finding · quantity · variable · definition · key-term — grounded in the full text
findingdropout prevents units from co-adapting too much— “This prevents units from co-adapting too much”content_tags.findings[0]
findingtraining samples from exponentially many thinned networks— “dropout samples from an exponential number of different “thinned” networks”content_tags.findings[1]
evidence status notefinding — QUOTE RECOVERED FROM THE PAPER'S OWN CHARACTERS. The recorded quote was LETTERS-ONLY IDENTICAL to this stretch of the staged text but not an exact substring of it - spaces, hyphens, ligature glyphs or mathematical operators differed, so it could never anchor. This is the file's own text between the same two letters: not produced by a rule about the damage, copied out of the file. Round-trip checked (the recovered span is letters-only equal to the original) and length-checked. The text as originally recorded is kept in evidence as extracted.content_tags.findings[1]
findingdropout reduces overfitting and beats other regularizers— “reduces overfitting and gives major improvements over other regularization methods”content_tags.findings[2]
findingdropout achieves state-of-the-art on many benchmarks— “obtaining state-of-the-art results on many benchmark data sets”content_tags.findings[3]
quantity0.5 probability p — typical unit-retention probability— “can simply be set at 0.5”content_tags.quantities[0]
quantity2 hidden layers — example net in Figure 1— “A standard neural net with 2 hidden layers”content_tags.quantities[2]
quantity~1 probability — input units are retained with probability near 1— “the optimal probability of retention is usually closer to 1”content_tags.quantities[3]
variableoverfitting (the problem dropout addresses)— “overfitting is a serious problem in such networks”content_tags.variables[3]
definitiondropout— “The term “dropout” refers to dropping out units (hidden and visible) in a neural network.”content_tags.definitions[0]
evidence status notedefinition — QUOTE RECOVERED FROM THE PAPER'S OWN CHARACTERS. The recorded quote was LETTERS-ONLY IDENTICAL to this stretch of the staged text but not an exact substring of it - spaces, hyphens, ligature glyphs or mathematical operators differed, so it could never anchor. This is the file's own text between the same two letters: not produced by a rule about the damage, copied out of the file. Round-trip checked (the recovered span is letters-only equal to the original) and length-checked. The text as originally recorded is kept in evidence as extracted.content_tags.definitions[0]
definitionthinned network— “The thinned network consists of all the units that survived dropout (Figure 1b).”content_tags.definitions[1]
definitionoverfitting— “will be the result of sampling noise, so they will exist in the training set but not in real”content_tags.definitions[2]
definitionmodel combination— “Model combination nearly always improves the performance of machine learning methods”content_tags.definitions[3]
key-termsdropout, overfitting, neural networks, regularization, thinned networks, model combination, co-adapting, deep learning, training, hidden units
Concepts
terms this paper carries, each with the sentence it was cut from — the layer that joins one paper to another. Terms with no quote yet are on CONCEPTS.html.
conceptdropout— “Applying dropout to a neural network amounts to sampling a “thinned” network from it”concepts[0]
conceptgeometric mean— “We propose to do this by approximating an equally weighted geometric mean of the predictions of an exponential number of learned models that share parameters”concepts[4]
conceptsexual reproduction— “A motivation for dropout comes from a theory of the role of sex in evolution (Livnat et al., 2010). Sexual reproduction involves taking half the genes of one parent and half of the other, adding a very small amount of random mutation, and combining them to produce an offspring”concepts[5]
conceptthinned— “Applying dropout to a neural network amounts to sampling a “thinned” network from it”concepts[6]
conceptmodel combination— “Model combination nearly always improves the performance of machine learning methods”concepts[7]
Statistics — cross-field join keys
field-invariant statistical terms, used in their statistical sense (gated on a number / symbol / test). A p-value or a standard deviation means the SAME thing in physics, biology, psychology and sociology — so these are the strongest cross-field join keys. Grounded verbatim.
Bayesian— “This can sometimes be approximated quite well for simple or small models (Xiong et al., 2011; Salakhutdinov and Mnih, 2008), but we would like to approach the performance of the Bayesian gold standard using considerably less computation.”content_tags.statistics[0]
mean μ as written: mean of— “We propose to do this by approximating an equally weighted geometric mean of the predictions of an exponential number of learned models that share parameters.”content_tags.statistics[1]
regression β as written: linear regression— “The marginalization of dropout noise in the context of linear regression was discussed in Srivastava (2013).”content_tags.statistics[3]
evidence status noteregression — QUOTE REPAIRED: the extractor split a hyphen-space and the quote was recorded faithfully with the damage in it, which made it unanchorable. The repaired string is an EXACT SUBSTRING of the staged text - that is why it was accepted, not because a rule produced it. The text as originally recorded is kept in evidence as extracted.content_tags.statistics[3]
standard-deviation SD/σ— “Thereafter, the Monte-Carlo method is slightly better than the approximate method but well within one standard deviation of it.”content_tags.statistics[4]

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