Extract Panel Structure from an MST Route Map

Given a binary transition matrix that defines the Multistage-Adaptive Test (MST) structure, this function extracts key panel information: the module configuration by stage, all valid test pathways, the number of modules per stage, and the total number of stages.

Usage

panel_info(route_map)

Arguments

route_map: A binary square matrix defining the MST transition structure, where a value of 1 at row i, column j indicates that a test taker can be routed from module i to module j. This is equivalent to the transMatrix argument in the randomMST() function of the mstR package (Magis et al., 2017). See reval_mst for details on how to construct this matrix.

Value

A named list with four elements:

config: A named list of length equal to the number of stages. Each element is an integer vector of module indices belonging to that stage. Names are "stage.1", "stage.2", etc.
pathway: An integer matrix of all valid test pathways, with one row per pathway and one column per stage. Row names are "path.1", "path.2", etc. Columns correspond to the module index administered at each stage.
n.module: A named integer vector giving the number of modules in each stage.
n.stage: An integer scalar giving the total number of stages.

Details

The function identifies stage-1 modules as those with no incoming transitions (column sum of route_map equals zero). It then traverses the route map stage by stage, collecting modules reachable from the previous stage. All logically possible pathways are enumerated via expand.grid(), and pathways that violate the transition constraints in route_map are removed. The remaining pathways are sorted and returned as a matrix.

References

Magis, D., Yan, D., & von Davier, A. A. (2017). Computerized adaptive and multistage testing with R: Using packages catR and mstR. Springer.

Examples

# Use the 1-3-3 simMST panel route map
route_map <- simMST$route_map
pinfo <- panel_info(route_map)

# Stage configuration: which modules belong to which stage
pinfo$config
#> $stage.1
#> [1] 1
#> 
#> $stage.2
#> [1] 2 3 4
#> 
#> $stage.3
#> [1] 5 6 7
#> 

# All valid pathways (rows = pathways, columns = stages)
pinfo$pathway
#>        stage.1 stage.2 stage.3
#> path.1       1       2       5
#> path.2       1       2       6
#> path.3       1       3       5
#> path.4       1       3       6
#> path.5       1       3       7
#> path.6       1       4       6
#> path.7       1       4       7

# Number of modules per stage
pinfo$n.module
#> stage.1 stage.2 stage.3 
#>       1       3       3 

# Total number of stages
pinfo$n.stage
#> [1] 3