Formal Sciences
Mathematics
Algebra
ElementScope CategorySub-ItemDefinitionLinear Algebra
1. Domain1.1 Scope of the DomainBoundariesThe range of phenomena the science includes and excludes.Studies vector spaces and linear transformations over fields or rings. Includes matrices, determinants, eigenvalues/eigenvectors, inner products, orthogonality, linear systems, bases, dimension, diagonalization, spectral theory, and canonical forms. Excludes nonlinear transformations except when linearized; excludes general module theory except when specializing to vector spaces.
ScaleThe spatial, temporal, or organizational level at which the science operates (e.g., quantum, cellular, social, cosmic).Operates at algebraic, geometric, and computational scales: finite-dimensional and infinite-dimensional spaces; coordinate systems; linear mappings; matrix representations; continuous vs. discrete vector structures.
1.2 Ontological CommitmentsEntitiesThe kinds of things assumed to exist within the domain (particles, organisms, agents, fields, etc.).Vectors, scalars, matrices, linear maps, bases, subspaces, eigenvalues, eigenvectors, linear systems, inner products, orthonormal sets, projections, canonical forms.
PropertiesThe fundamental attributes these entities possess (mass, charge, genotype, preference, etc.).Linearity (additivity + scalar multiplication), dimension, independence, spanning, invertibility, orthogonality, norms, rank, determinant, spectral properties, singularity, stability under linear combinations.
CategoriesThe basic ontological types used to classify domain elements (substances, processes, relations, structures).Finite-dimensional vs infinite-dimensional vector spaces; Euclidean vs abstract vector spaces; inner-product spaces; normed spaces; orthogonal/unitary spaces; subspaces; direct sums; column/row spaces; eigenspaces; matrix algebras.
1.3 State-VariablesVariablesThe measurable or definable properties that describe system conditions.Current vector coordinates; selected basis; matrix entries; rank; determinant; eigenvalue/eigenvector selection; projection coefficients; decomposition parameters (SVD, QR, Jordan).
ParameterizationHow variables encode and represent the system’s state.Encoding via coordinate systems, matrices, bases, transformation matrices, Gram–Schmidt orthogonalization, spectral decompositions, change-of-basis matrices, block decompositions.
1.4 Admissible IdealizationsSimplificationsConceptual reductions used to make the domain tractable (point masses, rational agents, perfect gases).Assuming finite-dimensional contexts; treating bases as orthonormal; ignoring numerical instability; assuming exact arithmetic; focusing on diagonalizable matrices; treating infinite-dimensional spaces via finite truncations.
Validity ConditionsThe limits and contexts in which idealizations hold or break down.Break down in infinite-dimensional settings; numerical instability affects orthogonality; non-diagonalizability requires Jordan form; approximate methods fail for ill-conditioned systems; exact arithmetic assumptions break in floating-point.
1.5 Domain AssumptionsStructural AssumptionsBackground ontological stances such as determinism, continuity, randomness, discreteness.Vector addition and scalar multiplication obey axioms; linear mappings preserve structure; basis existence; dimension well-defined; inner-product axioms hold when introduced; matrix multiplication consistently encodes linear composition.
Implicit CommitmentsUnstated but necessary assumptions that shape the field’s conceptual structure.Assumes existence of bases (requires choice in general); assumes linear approximations meaningfully describe phenomena; assumes fields allow solutions of linear systems; assumes coordinate representation is faithful.
1.6 Internal Coherence RequirementsConsistencyThe demand that domain concepts do not contradict one another.Linear maps must preserve addition and scalar multiplication; matrix representations must agree with chosen bases; eigenstructures must align with characteristic polynomials; orthogonality must match inner-product definition; decomposition theorems must interoperate correctly.
CompatibilityThe requirement that entities, variables, and assumptions fit together into a unified descriptive framework.Requires harmony between vector-space axioms, matrix algebra, inner-product structures, spectral theory, coordinate geometry, and computational linear algebra (algorithms, stability).
2. Evidence Layer2.1 Observable PhenomenaObservablesThe aspects of the domain that can produce detectable signals accessible to measurement.Behavior of vectors under linear transformation; row/column dependencies; solvability of linear systems; matrix rank changes; eigenvalue/eigenvector structure; orthogonality patterns; projection behavior; determinant changes under operations; stability of decompositions (QR, SVD).
Detection LimitsThe boundaries of what can be resolved or sensed by current instruments or methods.Limited by numerical precision; inability to compute exact eigenvalues for large matrices; instability in near-singular systems; inability to directly observe infinite-dimensional structure; limitations of floating-point arithmetic; ill-conditioning hiding true rank.
2.2 Measurement SystemsUnitsStandardized quantifications (meters, seconds, volts, decibels, dollars, etc.) necessary for consistent comparison.Vector norms; matrix norms; determinant magnitude; rank value; condition number; eigenvalue magnitude; angle between vectors; projection coefficients; singular values; numerical error bounds.
InstrumentsDevices and tools (microscopes, spectrometers, sensors, surveys, detectors) used to produce measurements.Gaussian elimination solvers; LU/QR/SVD decomposition tools; eigenvalue algorithms; Gram–Schmidt orthogonalizers; matrix calculators; numerical linear algebra libraries (LAPACK, BLAS); symbolic algebra systems (Mathematica, Maple).
2.3 Operational DefinitionsDefinitionsTerms defined by specific measurement procedures, ensuring empirical clarity.Rank defined via dimension of row or column space; determinant defined via multilinear alternating form; eigenvalues/eigenvectors defined via solving (Ax=\lambda x); orthogonality defined via inner product; projection defined via orthogonal decomposition; condition number defined via operator norm ratios.
ProceduresThe explicit steps required to perform a measurement in a reproducible way.Row reduction; computing determinants; solving linear systems; performing decompositions (QR, LU, SVD); computing eigenvalues/eigenvectors; orthogonalizing bases; projecting vectors; computing pseudoinverses; estimating condition numbers.
2.4 Data AcquisitionProtocolsFormal processes for gathering data under controlled or standardized conditions.Standardized matrix-generation methods; controlled sampling of random matrices; structured eigenvalue experiments; systematic basis construction; repeated row-reduction tests; consistent use of pivot strategies; performing decompositions under fixed tolerances.
SamplingRules determining which subset of the domain is measured and how representative it is.Sampling random vectors; sampling matrices from various distributions (uniform, Gaussian); selecting subspaces; sampling eigenvalue problems; sampling ill-conditioned or sparse matrices; sampling orthonormal sets.
2.5 Data Character & FormatData TypesThe form raw evidence takes (time series, spectra, images, counts, qualitative records).Matrices; vectors; row-reduced echelon forms; eigenvalue/eigenvector lists; decomposition outputs (U, Σ, V*); projection vectors; pseudoinverses; residuals for linear systems; condition number tables.
ResolutionThe granularity or precision with which data is captured.Determined by precision of floating-point arithmetic; granularity of decomposition outputs; stability of eigenvalue approximations; tolerance thresholds in algorithms; resolution limits in detecting near-linear dependence.
2.6 Reliability & CalibrationCalibrationAdjustment procedures ensuring instruments produce accurate results.Validating row-reduction results across algorithms; cross-checking eigenvalue computations; verifying decompositions by reconstruction; comparing projections under different bases; checking stability via perturbation tests; ensuring norm and inner-product accuracy.
Error CharacterizationIdentification and quantification of noise, uncertainty, bias, and measurement error.Numerical rounding errors; pivoting instabilities; loss of orthogonality in Gram–Schmidt; incorrect rank detection; eigenvalue drift; decomposition inaccuracies; sensitivity to conditioning; algorithmic failures on singular or near-singular matrices.
3. Structural Layer3.1 Patterns & RegularitiesLaws / RelationsStable, repeatable patterns governing how observables behave across conditions.Linearity (superposition principle); dimension laws; rank–nullity theorem; eigenvalue–eigenvector relationships; orthogonality relations; invariance of determinant under row operations (up to sign); spectral decomposition laws; canonical-form relations (Jordan, diagonalization).
InvariantsQuantities or properties that remain constant under transformations (symmetries, conservation laws).Dimension; rank; determinant (up to units); eigenvalues; singular values; norms; orthogonality; trace; characteristic/minimal polynomials; invariants under similarity transformations; subspace dimensions; condition number (in numerical settings).
3.2 Causal ArchitectureMechanismsUnderlying processes or structures that produce the observed regularities.Linear transformations inducing predictable geometric effects (rotation, reflection, projection, scaling); matrix multiplication encoding composition; eigenvalue mechanisms governing long-term behavior; orthogonalization via Gram–Schmidt; decomposition mechanisms revealing structure (QR, LU, SVD).
PathwaysOrganized sequences of interactions forming a causal chain or network.Matrix → row reduction → solution/x-space classification; matrix → eigenvalue computation → diagonalization or Jordan form; vector set → Gram–Schmidt → orthonormal basis; transformation → decomposition → analysis (e.g., A = UΣV* in SVD).
3.3 Theoretical VocabularyConceptsCore terms that encode the domain’s structure (force, gene, equilibrium, field).Vector, scalar, basis, dimension, linear independence, span, subspace, rank, kernel, image, determinant, eigenvalue, eigenvector, projection, norm, inner product, linear operator, similarity, orthonormal set, decomposition.
ClassificationsTaxonomies, categories, or typologies that organize entities and relations.Finite vs infinite dimensional spaces; Euclidean vs general inner-product spaces; diagonalizable vs non-diagonalizable operators; symmetric/Hermitian vs general matrices; normal vs non-normal matrices; singular vs nonsingular operators; orthogonal/unitary transformations.
3.4 Formal RepresentationsEquationsMathematical constructs expressing laws, relations, or mechanisms.Ax = b; A = PDP⁻¹ (diagonalization); A = PJP⁻¹ (Jordan form); A = QR; A = UΣV* (SVD); det(A) formulas; rank–nullity: dim(V)=rank(A)+nullity(A); projection: proj_u(v)=((v·u)/(u·u))u; eigenvalue equation: Av=λv.
ModelsStructured representations—mathematical, computational, or conceptual—used to predict and explain phenomena.Matrix models of linear transformations; geometric models (vectors in ℝⁿ); decomposition diagrams; coordinate-change diagrams; subspace lattices; operator-spectral models; row-reduced echelon form as structural representation.
3.5 Idealized StructuresSimplified ModelsPurposeful abstractions that capture essential dynamics while omitting irrelevant detail.Orthogonal bases; diagonalizable matrices; truncated infinite-dimensional settings; idealized exact arithmetic; symmetric/Hermitian operator assumptions; simplified canonical forms; ignoring conditioning.
Limit ConditionsRegimes where specific models or approximations hold (classical vs. quantum, linear vs. nonlinear).Idealizations fail in defective matrices (non-diagonalizable); infinite dimensions require functional analysis; numerical instability breaks orthogonality; ill-conditioned systems distort decomposition accuracy; non-normal matrices violate many geometric intuitions.
3.6 Integrative FrameworksUnifying TheoriesHigher-order structures that connect disparate laws or mechanisms under a coherent whole.Spectral theory unifying operators and decompositions; functional calculus linking matrices to polynomials; singular value decomposition connecting geometry and analysis; duality theory (row/column spaces); unification with multilinear algebra via tensor spaces.
Interdisciplinary LinksPoints where the theory connects to adjacent sciences or larger explanatory systems.Physics (quantum operators); engineering (signal processing via SVD, PCA); computer science (machine learning, optimization, numerical algorithms); statistics (covariance matrices, regression); geometry (transformations, projections); economics (input–output models).
4. Method Layer4.1 Inquiry DesignExperimental DesignStructured plans for manipulating variables to test causal claims.Manipulating matrices (changing entries, sparsity, conditioning); altering bases; varying decomposition methods (QR, LU, SVD); modifying norms; perturbing linear systems; testing effects of similarity transforms; adjusting vector sets to test independence or orthogonality.
Observational DesignSystematic approaches for gathering non-manipulated data (surveys, field studies, natural experiments).Observing natural behavior of transformations under fixed matrices; monitoring stability of eigenvalues; observing rank changes under row operations; watching projections evolve; tracking norms and angles; monitoring convergence of iterative solvers without altering the underlying system.
4.2 Testing & ValidationHypothesis TestingProcedures for evaluating whether evidence supports or contradicts specific claims.Testing linear independence; verifying that transformations are linear; checking rank–nullity relationships; validating orthogonality; testing diagonalizability; checking decomposition correctness (A=UΣV*, A=PJP⁻¹, A=QR); validating numerical solutions by residual norms.
ReplicationThe requirement that results be independently reproducible under similar conditions.Recomputing decompositions under different algorithms; repeating row-reduction; verifying eigenvalue computations via multiple methods; performing the same projection under different bases; recomputing condition numbers under varied perturbations.
4.3 Inference & EvaluationStatistical InferenceRules for drawing conclusions from noisy or incomplete data.Analyzing distributions of singular values across random matrices; evaluating average conditioning; assessing error growth in numerical solutions; comparing convergence rates of iterative solvers; analyzing stability across matrix families.
Model ComparisonCriteria (fit, simplicity, predictive accuracy, robustness) used to evaluate competing models.Comparing dense vs sparse matrix models; contrasting numerical vs symbolic methods; comparing decomposition methods (QR vs SVD vs LU); comparing eigenvalue algorithms; contrasting different norm-induced geometries; comparing bases and coordinate systems.
4.4 Error ManagementError AnalysisIdentification and quantification of random and systematic errors.Identifying rounding errors; detecting breakdowns in orthogonality; diagnosing rank misidentification; quantifying residuals in linear systems; identifying instability in eigenvalue computations; tracking algorithmic drift in iterative solvers; diagnosing ill-conditioning.
Bias ControlMethods for minimizing subjective, instrumental, or procedural biases.Avoiding biased sampling of “nice” matrices; ensuring diverse conditioning levels; preventing dependence on a single numerical library; controlling for basis choice; balancing dense vs sparse examples; avoiding overfitting of observations to well-behaved matrices.
4.5 Adjudication & RevisionPeer ScrutinyCollective evaluation of claims through critique, review, and debate.Reviewing correctness of decompositions; auditing eigenvalue/eigenvector results; cross-checking numerical conclusions across libraries; re-evaluating rank and independence claims; validating projections; reviewing perturbation analyses.
Theory RevisionProcedures for modifying, replacing, or discarding models based on new evidence.Updating decomposition methods; refining stability assumptions; modifying numerical algorithms; revising classification of matrices (normal, orthogonal, diagonalizable) based on new findings; adjusting tolerance thresholds; integrating improvements in numerical conditioning theory.
4.6 Integrity ConditionsTransparencyRequirements to disclose methods, data, assumptions, and limitations.Full disclosure of matrix formats, algorithms used, tolerance parameters, pivot strategies, decomposition settings, norm choices, and floating-point limitations; clear statement of numerical uncertainty.
Ethical StandardsNorms ensuring responsible conduct in experimentation, data handling, and publication.Honest error reporting; avoiding concealment of instability; ensuring reproducibility; clearly stating algorithmic limitations; acknowledging pathological matrices; maintaining rigor in linear-algebraic claims.