# Chapter 5 Computation

This section explains the basic computations needed for fitting and evaluating the Rasch model. We distinguish the following steps:

- Identify nature of the problem (5.1)
- Estimation of item parameters (5.2)
- Anchoring (5.2.2)
- Estimation of the D-score (5.3)
- Estimation of age-conditional references (5.4)

Readers not interested in these details may continue to model evaluation in Section 6.