Section 2: Developing/Assessing Logic Models

Specify the Prevention Mechanisms

How does the program prevent violence? The mechanisms for prevention are found in the linkages between outcomes and activities. Linkages express the logic of the program structure and assess its coherence. This is done by connecting each long?term and short?term outcome to the program activity (or activities) that is directly involved in its attainment (Rutman & Mowbray, 1983).

• Linkages between Outcomes and Program Activities

After the program activities have been considered, next to be considered are linkages between the program objectives and how these objectives will be (or are being) met by specific elements in the program. In developing the model, the evaluator may find that several of the interventions overlap. For example, the goal of "decreased isolation" may be met by providing home visits and referrals to local resources, and facilitating improvements in couple communication. Some activities and conditions may affect outcomes independently or in combination with others. The multiple interventions may also create a synergistic effect, where the combination of interventions is more effective than are the individual interventions alone.

An example of linkages is found in studies of perinatal home visiting. Several recent studies have demonstrated the efficacy of home-visiting programs in reducing the risk of child maltreatment (Chalk & King, 1998). Guterman's (1997) review of the research literature on early physical child abuse and neglect prevention indicate that two activities--health education and linking families with formal and informal supports--are essential in reducing the risk for maltreatment.

The Prenatal and Early Childhood Nurse Home Visitation Program is another highly regarded model providing services to low income first-time mothers and their babies (Olds, Henderson, Kitzman & Cole, 1995). The program activities address women's health behaviors in pregnancy related to substance abuse, nutrition, risk factors for prematurity, low birthweight and infant impairment. After delivery, the focus shifts to enhancing caregiving, and for mothers, there is a particular focus on preventing unintended pregnancies, school drop-out and welfare dependence. This program has demonstrated prolonged improvement in the life course of program mothers and their children in areas such as health and social functioning.

Activities and conditions with no clear link to outcomes should be considered carefully to determine whether they contribute to goal attainment at all. Program activities with no clear link to outcomes may represent program elements that should be modified or eliminated. However, before decisions are made about eliminating an activity, the evaluator should explore with program staff to determine what they see as the linkage between what they are doing and what they hope to accomplish. Program staff may implicitly be doing a set of activities tied to their own embedded theory, part of an implicit but very informed model that can be made explicit. Below are questions to help make the linkages between program activities and program outcomes (see also Worksheet 2.4).

• What problems do (or will) clients/communities have?
• How do the program activities address these problems?
• What strengths do clients/communities have?
• How can program activities heighten client/community strengths?

• Specify the Target Population or Community

The target population is the group the program under evaluation is trying to reach. This step specifies the characteristics of the clients or communities that will be targeted by the prevention program. These characteristics are placed in Column A of the logic model diagram. For prevention programs, these include client background characteristics such as gender, age, and marital and parenting status, as well as risk factors that are related to the behaviors and attitudes to be prevented by the program. For programs focusing on communities, the evaluator might be interested in population density, socioeconomic status, geographical location, climate and neighborhood resources (see also Worksheet 2.5a).

• Linkages Between Program Activities and Target Population/Community

In this final task, the evaluator should consider the program activities that address the potential difficulties that might be found in the target population or target community.

• How were eligibility criteria developed for this program?
• What are the population/community characteristics associated with family violence risk?

This step involves working from the program activities to the characteristics of the target population. Why will the identified program activities make a difference for the target population? Different components of the program may address specific areas of risk. For determining the target population and why they are in the program, the evaluator may want to refer to Worksheet 2.5a. This will allow the evaluator to complete column A on Figure 2.3.

• Who are the clients the program serves?
• What are the eligibility criteria for the program?

On worksheet 2.5b, similar questions are asked for communities.

• Where is the community located?
• How dense is the population?
• How was this community selected? What are the eligibility criteria?