| dif_test | Score (LM) tests of differential step and item functioning |
| dsf | Likelihood ratio tests of differential step functioning |
| dsf_design | Multigroup TPPCM design with group.equal and group.partial |
| get_parts | Components of a fitted model |
| irt_pars | Item and group parameters in a compact table |
| item_test | Item-level score tests |
| m2 | Limited-information goodness of fit: M2, RMSEA2, SRMSR, CFI, TLI |
| mi | Modification indices for single step discriminations |
| score_test | Score test against a less restricted TPPCM |
| sim_tppcm | Simulate item responses from a TPPCM |
| step_info | Step, item and test information |
| tppcm | Step design for the TPPCM and its submodels |
| tppcmtree | TPPCM trees: model-based recursive partitioning of step discriminations |
| wald_test | Wald test of equal step discriminations within items |
| xxirt_tppcm | Fit TPPCM-family models with sirt::xxirt() |
| xxirt_vcov | Covariance matrix of an xxirt fit with shared or fixed parameters |