The methods registry: what nomologR computes, and where it comes from

nomo_methods() returns a machine-readable registry of the statistical methods nomologR implements. Each entry records the workflow stage, where the method sits in the literature, what it estimates, its key assumptions, the function that implements it, the computational engine, and DOI-verified references.

Usage

nomo_methods(x = NULL, stage = NULL, lineage = NULL, references = FALSE)

Arguments

x: Optional nomologR result object. If supplied, only the methods actually used in producing that object are returned, in registry order. If NULL (default), the whole registry is returned.
stage: Optional character vector restricting the result to these workflow stages. One or more of "screen", "factors", "efa", "cfa", "compare", "reliability", "validity", "invariance", "network", "workflow".
lineage: Optional character vector restricting the result to "historical", "contemporary", or "emerging" methods.
references: If FALSE (default), each row is one method and the references column holds short in-text citations. If TRUE, the result is expanded to one row per method per reference, with full citation and doi columns, suitable for a reference list.

Value

A tibble with columns id, stage, method, lineage, role, estimand, assumptions, implemented_by, engine, introduced, and contemporary_practice. With references = FALSE there is one row per method, and references holds short in-text citations. With references = TRUE there is one row per method-reference pair, with citation_key, citation, and doi.

Details

The registry answers a question learners ask constantly and software rarely answers: why this method, and where did it come from? Every entry carries a lineage label:

"historical": techniques a reader will meet in published work, retained so they can be recognized and interpreted. They are labeled and qualified.
"contemporary": what the current methodological literature recommends.
"emerging": recent proposals with a smaller evidence base.

A lineage label summarizes where a method sits in the literature. It is a teaching aid, not a claim that an older method is always wrong.

Two columns record how practice changed:

introduced: the year of the publication that introduced the method. It is given only when the registry cites that publication, and is NA when the registry cites only a later review or critique. It is never dated from a secondary source.
contemporary_practice: for a historical method, the registry's contemporary methods that now address the question it answered, such as parallel analysis for the eigenvalue-greater-than-one rule, or omega for coefficient alpha.

vignette("research-basis") draws a timeline from these columns.

The role column says how nomologR uses the method: "primary" evidence, "supporting" evidence, or "context". A "context" method is displayed for recognition and is deliberately excluded from any synthesis: the eigenvalue-greater-than-one rule and fixed fit-index cutoffs are shown so a reader can interpret older reports, never so nomologR can act on them.

The registry describes only what the package actually computes. Methods that are planned but not implemented are discussed in the research-basis article and tracked in issues; they are deliberately absent here, so that nomo_methods(run) can never credit a run with a method it did not use.

Passing a nomologR result object returns only the methods that object actually used, which is what nomo_report() cites.

Examples

# The whole registry
nomo_methods()
#> # A tibble: 89 × 12
#>    id      stage method lineage role  estimand assumptions implemented_by engine
#>    <chr>   <chr> <chr>  <chr>   <chr> <chr>    <chr>       <chr>          <chr> 
#>  1 missin… scre… Item … contem… supp… Proport… Descriptiv… nomo_screen()  nomol…
#>  2 respon… scre… Respo… contem… supp… Categor… Requires i… nomo_screen()  nomol…
#>  3 item_r… scre… Corre… contem… supp… Correla… Depends on… nomo_screen()  nomol…
#>  4 item_t… scre… Fixed… histor… cont… A conve… No simulat… nomo_screen()  nomol…
#>  5 near_z… scre… Near-… contem… supp… Frequen… Heuristic … nomo_screen()  nomol…
#>  6 long_s… scre… Long-… contem… supp… Longest… Reads raw … nomo_screen()  nomol…
#>  7 inter_… scre… Inter… contem… supp… Within-… Detects ra… nomo_screen()  nomol…
#>  8 mahala… scre… Mahal… contem… supp… Multiva… Unaffected… nomo_screen()  nomol…
#>  9 even_o… scre… Even-… contem… supp… Within-… Needs at l… nomo_screen()  nomol…
#> 10 psycho… scre… Psych… contem… supp… Within-… Needs at l… nomo_screen()  nomol…
#> # ℹ 79 more rows
#> # ℹ 3 more variables: introduced <int>, contemporary_practice <chr>,
#> #   references <chr>

# What is shown only as historical context, and why
nomo_methods(lineage = "historical")[, c("method", "role", "assumptions")]
#> # A tibble: 20 × 3
#>    method                                               role       assumptions  
#>    <chr>                                                <chr>      <chr>        
#>  1 Fixed item-total correlation reference (about .30)   context    No simulatio…
#>  2 Eigenvalue-greater-than-one rule                     context    Over-extract…
#>  3 Scree test                                           context    Requires sub…
#>  4 Kaiser-Meyer-Olkin sampling adequacy                 supporting Supporting a…
#>  5 Bartlett's test of sphericity                        supporting Strongly sam…
#>  6 Orthogonal (varimax) rotation                        context    Forces facto…
#>  7 Fixed loading cutoff                                 context    No universal…
#>  8 Chi-square exact-fit test                            supporting Power increa…
#>  9 Fixed fit-index cutoffs                              context    Derived unde…
#> 10 Modification indices                                 context    Data-driven …
#> 11 Coefficient alpha                                    supporting Assumes equa…
#> 12 Schmid-Leiman decomposition                          supporting Originally a…
#> 13 Standardized loadings and average variance extracted supporting Convergent e…
#> 14 Fornell-Larcker comparison                           context    Simulation w…
#> 15 Unit-weighted sum or mean score                      primary    Not a model-…
#> 16 Regression (Thurstone) factor scores                 primary    Indeterminat…
#> 17 Bartlett factor scores                               primary    Indeterminat…
#> 18 Nomological network of construct relations           primary    Evidence for…
#> 19 Listwise deletion                                    context    Requires dat…
#> 20 Pairwise deletion                                    context    Requires dat…

# How practice changed: historical methods and what now does their work
old <- nomo_methods(lineage = "historical")
old[!is.na(old$contemporary_practice),
    c("introduced", "method", "contemporary_practice")]
#> # A tibble: 15 × 3
#>    introduced method                                       contemporary_practice
#>         <int> <chr>                                        <chr>                
#>  1         NA Fixed item-total correlation reference (abo… item_rest_correlation
#>  2       1954 Eigenvalue-greater-than-one rule             parallel_analysis; m…
#>  3       1966 Scree test                                   parallel_analysis    
#>  4       1958 Orthogonal (varimax) rotation                oblique_rotation     
#>  5         NA Fixed loading cutoff                         loading_diagnostics  
#>  6       1969 Chi-square exact-fit test                    incremental_fit; rms…
#>  7       1999 Fixed fit-index cutoffs                      local_strain         
#>  8         NA Modification indices                         local_strain; revisi…
#>  9       1951 Coefficient alpha                            omega                
#> 10       1957 Schmid-Leiman decomposition                  bifactor_model       
#> 11       1981 Fornell-Larcker comparison                   htmt2; latent_correl…
#> 12         NA Unit-weighted sum or mean score              parallel_model_test  
#> 13       1955 Nomological network of construct relations   two_step_sem; predic…
#> 14         NA Listwise deletion                            fiml; missing_sensit…
#> 15         NA Pairwise deletion                            fiml; missing_sensit…

# A reference list for one stage
nomo_methods(stage = "reliability", references = TRUE)[, c("method", "citation")]
#> # A tibble: 24 × 2
#>    method                                         citation                      
#>    <chr>                                          <chr>                         
#>  1 Model-based coefficient omega                  Dunn, T. J., Baguley, T., & B…
#>  2 Model-based coefficient omega                  McNeish, D. (2018). Thanks co…
#>  3 Model-based coefficient omega                  Flora, D. B. (2020). Your coe…
#>  4 Model-based coefficient omega                  Bell, S. M., Chalmers, R. P.,…
#>  5 Reliability on the ordered-score scale         Green, S. B., & Yang, Y. (200…
#>  6 Coefficient alpha                              Cronbach, L. J. (1951). Coeff…
#>  7 Coefficient alpha                              Sijtsma, K. (2009). On the us…
#>  8 Bootstrap confidence intervals for reliability Kelley, K., & Pornprasertmani…
#>  9 Omega hierarchical                             Reise, S. P. (2012). The redi…
#> 10 Omega hierarchical                             Reise, S. P., Bonifay, W. E.,…
#> # ℹ 14 more rows