Seven perspectives

Methods divide for more than one reason. The question differs, certainly. But so do the assumptions placed on the data, the criteria for what counts as good, and the constraints on computation. Change any one of those and a different method suits the same prediction task.
The seven are not mutually exclusive; they look at different dimensions. The same equation often reads in several of them at once. Ridge regression, for instance, is a penalty in the geometric view, a MAP estimate under a Gaussian prior in the Bayesian view, and a control on complexity in learning theory. In the tables, a session that fits more than one perspective has the related perspectives named alongside it.

1

Geometry (least squares)

Minimize the sum of squared deviations. Concerned with how the structure of the data and the model is represented.What it looks at: how structure is represented

2

Frequentist (sampling variation, estimation, testing)

Judge the quality of an estimate or a decision by how it varies when the sample is drawn again.What it looks at: how uncertainty is handled

3

Bayesian

Combine what was known before observing with the data, and update belief into a posterior distribution.What it looks at: how uncertainty is handled

4

Learning theory

Keep the loss on data not yet seen in view, and balance fit against complexity.What it looks at: how predictive performance is judged

5

Information theory

Treat a short encoding as a good explanation.What it looks at: evaluation in terms of information

6

Games and adversaries

Read learning as the interaction of several agents in competition.What it looks at: interaction between agents

7

Causality

Ask what would happen under an intervention — a counterfactual question.What it looks at: the kind of question asked

→ Read the seven perspectives in equations A child page setting out the equation at the centre of each one, and how to read the symbols. Beyond it sit twenty-one pages on the methods used in actual research, grouped by perspective.

How to read the tables

Conceptsthe idea is handled in words and pictures Computationactually computed and run Derivationequations derived, properties proved
Calc Isingle-variable calculusCalc IImultivariable, gradient, HessianLin Imatrix computation, linear systemsLin IIeigenvalues, orthogonalization, decompositionsolid = used in the session / dashed = connected when taken further

The number of rows does not stand for how thoroughly something is covered. Some rows gather several sessions together, and the breadth of a perspective differs from item to item. For comparison, read the stage column.

1

Geometry (least squares)

Minimize the sum of squared deviations. Concerned with how the structure of the data and the model is represented.What it looks at: how structure is represented

20 primary · 4 related
CourseSessionMethod or topic (related perspectives)StageMathematics usedConnects toNote
Statistics IS2 · S3Averages and spreadComputation—Lin ISummarize a distribution with sums and sums of squares. Reading them as norms comes later
Statistics IS5Correlation and causation CausalityComputation—Lin IRead correlation as covariance. The causal argument is handed on to Statistics II
Statistics IS10Simple and multiple regression (OLS) FrequentistComputation—Lin ILin IIThe normal equations and projection. Assume normal errors and it agrees with maximum likelihood
Statistics IS13Principal component analysisComputation—Lin IIWhat the eigendecomposition means is covered; computing it numerically is not
Social ResearchS5Using official statisticsConcepts—Lin IRead aggregate tables. Treating them as matrices comes later
Applied Info. LiteracyS4 · S6Distributions, averages, descriptive statisticsComputation—Lin ISummarize, in numbers, data the students gathered themselves
Applied Info. LiteracyS9Graphs and scatter plotsComputation——Read a relationship between two variables by eye. No equations
BehaviormetricsS8Correlation and scatter plotsComputation—Lin ICompute the correlation coefficient in R
Intro. to InformationS6 · S7Descriptive statistics and reading dataComputation——Aggregation in a spreadsheet. No equations
Intro. to InformationS10Reading graphsConcepts——Designing axes and comparisons. Figures that mislead
Introduction to Data Usein preparationS10Basics of descriptive statisticsComputation—Lin IMean, variance and standard deviation in Excel
Introduction to Data Usein preparationS12 · S13Reading graphs, fake statistics CausalityConcepts——Designing figures, and misreading them. The trap of stratification is touched on
Big Data Analysisin preparationS6 · S7Multiple regression FrequentistComputation—Lin ILin IIThe design matrix and the normal equations. Numerical decomposition comes later
Big Data Analysisin preparationS8 · S9Principal component analysisComputation—Lin IIEigendecomposition and SVD
Big Data Analysisin preparationS10 · S11k-meansComputation—Lin IMinimizing the within-cluster sum of squares
Big Data Analysisin preparationS12 · S13PLS regression Learning theoryComputation—Lin IIRegression in a latent space. Chosen by cross-validation
Big Data Apps Iin preparationS5 · S6PCA and biplotsComputation—Lin IIVisualizing dimension reduction
Big Data Apps IIin preparationS2Coordinate and projection transformsComputation—Lin ITransforming spatial data is matrix arithmetic
Big Data Apps IIin preparationS9 · S11 · S12PCA, k-means, PLSComputation—Lin ILin IICompressing features, and finding the groupings in them
Speech Processingin preparationS5MFCC (mel filterbank, DCT)Computation—Lin ICompressing features by an orthogonal transform
Statistics IIS11Confounding and spurious correlation (primarily Causality)Computation—Lin ILin IIAdjusting for covariates. Checked by computing a partial correlation
Applied Info. LiteracyS7Cross-tabulation (primarily Frequentist)Computation—Lin IThe joint distribution of categories. The doorway to the chi-square test
Big Data Apps Iin preparationS7 · S8k-means and stability assessment (primarily Learning theory)Computation—Lin IWhether a clustering reproduces. Generalization made tangible
Big Data Apps Iin preparationS9 · S10PLS-DA and cross-validation (primarily Learning theory)Computation—Lin IISeparate training from validation. See overfitting as a number
2

Frequentist (sampling variation, estimation, testing)

Judge the quality of an estimate or a decision by how it varies when the sample is drawn again.What it looks at: how uncertainty is handled

16 primary · 2 related
CourseSessionMethod or topic (related perspectives)StageMathematics usedConnects toNote
Statistics IS6Samples and the central limit theoremConcepts—Calc ICalc IIFelt through simulation. Not proved
Statistics IS7Point and interval estimationComputationCalc ICalc IICheck the idea of coverage by building the intervals
Statistics IS8 · S9t-tests and ANOVAComputation—Lin ILin IIDecomposing a sum of squares. Reading it as a projection comes later
Statistics IIS4 · S5Binomial, Poisson, normal distributionsConceptsCalc ICalc ISet up a probability model. Integrating the density is not covered
Statistics IIS6Sampling distributions and the CLT revisitedConcepts—Calc IIBreak the independence the standard error formula assumes, and see what follows
Statistics IIS7The theory of interval estimationComputationCalc ICalc IIThe t distribution and degrees of freedom. Coverage seen by simulation
Statistics IIS8 · S9Multiple comparisons, effect size, criticism of p-values Learning theoryComputation—Calc IWhat repeating a test does. Reporting the size of an effect
Social ResearchS10Census and sample surveyConcepts—Calc ISampling error and the sample size needed. Selection bias sits outside the equations
Applied Info. LiteracyS7Cross-tabulation GeometryComputation—Lin IThe joint distribution of categories. The doorway to the chi-square test
BehaviormetricsS9The chi-square testComputation—Calc IThe gap from the expected frequencies
BehaviormetricsS10 · S11t-tests and paired t-testsComputation—Lin IComparing two groups. The structure of the data changes the test
BehaviormetricsS13 · S14ANOVA and multiple comparisonsComputation—Lin ILin IIDecomposing a sum of squares, and adjusting for the number of comparisons
Introduction to Data Usein preparationS4The history of social research and the birth of statisticsConcepts—Calc IHow the frequentist view came about, followed through its history
Introduction to Data Usein preparationS11Sample and population, the law of large numbers, the CLTConcepts—Calc IThe doorway to inferential statistics
Big Data Apps IIin preparationS5Kernel density estimationComputation—Calc IIChoosing the bandwidth is choosing how much to smooth
Speech Processingin preparationS7HMM, GMM, self-supervised learning BayesianComputation—Calc IILin IMaximizing likelihood by EM. Not derived
Statistics IS10Simple and multiple regression (OLS) (primarily Geometry)Computation—Lin ILin IIThe normal equations and projection. Assume normal errors and it agrees with maximum likelihood
Big Data Analysisin preparationS6 · S7Multiple regression (primarily Geometry)Computation—Lin ILin IIThe design matrix and the normal equations. Numerical decomposition comes later
3

Bayesian

Combine what was known before observing with the data, and update belief into a posterior distribution.What it looks at: how uncertainty is handled

3 primary · 1 related
CourseSessionMethod or topic (related perspectives)StageMathematics usedConnects toNote
Statistics IS12The doorway to Bayesian statisticsComputation—Calc ICalc IIWith discrete hypotheses, the posterior is arithmetic
Statistics IIS2 · S3Conditional probability and Bayes’ theoremComputation—Calc IHow much the prior bites, checked by counting in the finite case
Statistics IIS12 · S13Information cascades and Condorcet’s jury theorem GamesComputation—Calc ISequential updating, and group judgement once independence has broken, by simulation
Speech Processingin preparationS7HMM, GMM, self-supervised learning (primarily Frequentist)Computation—Calc IILin IMaximizing likelihood by EM. Not derived
4

Learning theory

Keep the loss on data not yet seen in view, and balance fit against complexity.What it looks at: how predictive performance is judged

4 primary · 5 related
CourseSessionMethod or topic (related perspectives)StageMathematics usedConnects toNote
Big Data Apps Iin preparationS7 · S8k-means and stability assessment GeometryComputation—Lin IWhether a clustering reproduces. Generalization made tangible
Big Data Apps Iin preparationS9 · S10PLS-DA and cross-validation GeometryComputation—Lin IISeparate training from validation. See overfitting as a number
Speech Processingin preparationS8Conformer and WhisperConcepts—Calc IILarge-scale training and generalization. Backpropagation is not derived
Speech Processingin preparationS9Evaluation metrics (WER, CER)Computation——Designing what counts as an error. Compared against the human error rate
Statistics IS11Model selection and AIC (primarily Information theory)ConceptsCalc ICalc IBalancing fit against complexity. The code-length argument is not covered
Statistics IIS8 · S9Multiple comparisons, effect size, criticism of p-values (primarily Frequentist)Computation—Calc IWhat repeating a test does. Reporting the size of an effect
Big Data Analysisin preparationS5Approximation algorithms (primarily Information theory)ComputationCalc ICalc ISketches and probabilistic data structures. Trading error against capacity
Big Data Analysisin preparationS12 · S13PLS regression (primarily Geometry)Computation—Lin IIRegression in a latent space. Chosen by cross-validation
Speech Processingin preparationS13Deepfake detection (primarily Games and adversaries)Concepts—Calc IIThe chase between generation and detection, read as a min–max
5

Information theory

Treat a short encoding as a good explanation.What it looks at: evaluation in terms of information

2 primary · 0 related
CourseSessionMethod or topic (related perspectives)StageMathematics usedConnects toNote
Statistics IS11Model selection and AIC Learning theoryConceptsCalc ICalc IBalancing fit against complexity. The code-length argument is not covered
Big Data Analysisin preparationS5Approximation algorithms Learning theoryComputationCalc ICalc ISketches and probabilistic data structures. Trading error against capacity
6

Games and adversaries

Read learning as the interaction of several agents in competition.What it looks at: interaction between agents

1 primary · 1 related
CourseSessionMethod or topic (related perspectives)StageMathematics usedConnects toNote
Speech Processingin preparationS13Deepfake detection Learning theoryConcepts—Calc IIThe chase between generation and detection, read as a min–max
Statistics IIS12 · S13Information cascades and Condorcet’s jury theorem (primarily Bayesian)Computation—Calc ISequential updating, and group judgement once independence has broken, by simulation
7

Causality

Ask what would happen under an intervention — a counterfactual question.What it looks at: the kind of question asked

3 primary · 2 related
CourseSessionMethod or topic (related perspectives)StageMathematics usedConnects toNote
Statistics IIS10Introduction to causal inference (RCTs and observational studies)Concepts—Lin IThe difference between intervening and observing. Identification assumptions handled in words
Statistics IIS11Confounding and spurious correlation GeometryComputation—Lin ILin IIAdjusting for covariates. Checked by computing a partial correlation
Intro. to InformationS12Simpson’s paradoxConcepts—Lin IStratify and it reverses. A first encounter with confounding
Statistics IS5Correlation and causation (primarily Geometry)Computation—Lin IRead correlation as covariance. The causal argument is handed on to Statistics II
Introduction to Data Usein preparationS12 · S13Reading graphs, fake statistics (primarily Geometry)Concepts——Designing figures, and misreading them. The trap of stratification is touched on
—

Outside the statistical mathematics this map covers

Sessions concerned with design, ethics and communication, or with a different kind of mathematics, rather than with the mathematics of a method.

CourseSessionContentHow it is handled
Social ResearchS9, S11–S14Qualitative research (interviews, observation, ethnography)Handled as questions of design and ethics, of recording and interpretation
Applied Info. LiteracyS1–S3, S10–S13Planning a survey, publishing and presenting the resultsDesigning a survey, and communicating it
Big Data Analysisin preparationS1–S4The five Vs, columnar storage, the CAP theorem, DAGsDesigning the data platform. A different kind of mathematics is involved here: distributed systems, and computational complexity

What this table can and cannot show

Can show: nothing reaches the derivation stage

Almost every session sits at concepts or at computation. Deriving the equations and proving the properties is not part of any course currently taught here. Whether some other part of the curriculum carries that role is worth checking.

Can show: the games perspective has few points of contact

Only session 13 of Speech Processing. The information cascade in Statistics II sits close to it, in that it is about group judgement once independence has broken.

Cannot show: that fewer rows means thinner coverage

Geometry has many rows partly because descriptive statistics, visualization and matrix computation are all gathered under that one perspective. The scope of the classification and the unit of aggregation are mixed together here, so the number of rows cannot tell you how thoroughly a topic is covered.

Cannot show: that something is missing because the mathematical prerequisites are missing

That cannot be separated from what happens to be assigned to this teacher, from the hours available, from the stated goals, or from how the tags were applied. This table alone does not settle the cause.

There are stages within reach even without the prerequisite mathematics

With finitely many hypotheses, a Bayesian update is arithmetic. Take the probability of heads to be either 1/4 or 3/4, with a prior of 1/2 on each, and suppose three independent tosses all come up heads: the posterior probability of 3/4 is (3/4)³ ÷ ((1/4)³ + (3/4)³) = 27/28. Normalizing takes addition; no multivariable integration is needed.
Information theory can be introduced the same way, through the entropy of finitely many outcomes, with logarithms and a weighted average. Generalization, too, asks for different prerequisites depending on whether a bound is being proved or the gap between training and unseen performance is being watched in an experiment. The question is not whether that mathematics has been studied, but which stage one chooses to work at.

The order the source document sets out, and what these courses touch

The order in which the source document places the mathematics, year by year. What the courses touch is noted alongside it. Whether that order is itself the right one is not examined here.

Year 1: sums of squares and inner products → normal equations and projection → extrema in one variable

Introduction to Data Use and Applied Information Literacy handle descriptive statistics and the idea of a sample, at the computation stage. Reading them as projections is not touched.

Year 2: QR, Cholesky, SVD → multivariable gradient and Hessian, IRLS

Statistics I goes as far as regression, AIC and PCA; Statistics II as far as probability, Bayes, and the doorway to causal inference. Computing the decompositions numerically is not covered.

Year 3: generalized eigenvalues, duality and KKT → kernels → alternating optimization in EM

Speech Processing handles EM, and the big-data courses handle PCA, k-means and PLS from the side of implementation. SVMs and kernel methods appear in no course here.

Year 4: Laplace approximation, variational inference, HMC → large-scale computation → backpropagation and SDEs

Session 8 of Speech Processing touches the training of large models. Bayesian computation, Gaussian processes, and the mathematics of generative models appear in no course here.

Source document: “Mathematical techniques and their relation to statistical methods and machine learning” (Onohara, September 2025). It is a set of notes Onohara wrote privately in order to think through the curriculum of the Faculty of Information Science, and it speaks for no one but its author. The seven perspectives and the mathematics tags come from it. The distinction between stages, and the assignment of each session, were worked out for this page.
The ideas themselves are explained in A Guide to Statistical Thinking, and which session of which course covers what is set out in the course map.