This resource book examines the value-added model approach when used in assessing early childhood Title I (ECT-I) programs. The evaluation design must be able to separate program effects from natural maturation. The basic idea behind the value-added model builds on the notion of natural maturation. The major strengths are that it does not require a comparison group or the use of a norm referenced test. The major weaknesses are its usefulness only for the assessment of skills or attributes which show a natural development with age over the duration of the program. Selection procedures may disguise the relationship between age and skill development among a particular group of program participants. Finally, it can require complex statistical calculations. This method attempts to derive a great deal of information from a situation with little data and little external control. The validity of results from the value-added model may be questioned in situations where one wishes to assess the short-term impact of an ECT-I program and the available sample size is relatively small. A possible solution is pooling data across multiple years of the program or across several sites that are implementing similar activities. (DWH)