| cusum | Generates CUSUM values for Rasch, 2PL and 3PL IRT model based on the Van Krimpen-Stoop & Meijer, (2002). | 
| cusum.cutoff | Generates critical values for CUSUM statisitcs. | 
| cusum.flag | Flags aberrant participants based on CUSUM statistics. | 
| cusum.plot | Generates CUSUM plot for specified IDs. | 
| cusum.poly | Generates CUSUM values for polytomous IRT model based on Van Krimpen-Stoop & Meijer, (2002). | 
| ex2PL | Example data set based on a simulated 2PL model. | 
| exGRM | Example data set based on a simulated GRM model. | 
| gh | Example data set based on a simulated GRM model. |