For assigning a value to an object or situation, you must have a reference. In assessing, the measure is only one of its components and the value judgement is given to interpret the difference resulting from the comparison of two measures: that it is, and that it is expected of result. The measures themselves are not good or bad, are simply a reflection of a situation. The meaning of these depends on what is considered as what “should be”1 .

Reasons to evaluate:

1. Measure the achievement of its goals.

– Does the system in accordance with its operational objectives?

– Is the system cost effective?

– The system produces the desired effect?

– Does the system work better than the procedures they replace?

– Does the system have any impact on its users?

– Does the system have any impact on the organization?

2. Having a tool to diagnose weaknesses in the functioning

– Does the information handling system quality requirements needed to produce the desired results?

– Is done with correction documentary operations in the system?

– Does the system all the information needed to respond to the needs of their users?

3. Facilitate decision-making process

– Continue or cancel the service being evaluated.

– Add or disposal techniques and procedures.

– Modify strategies.

– Establish new information systems.

– Accept the introduction of new theories and techniques.

4. Allow comparison between systems through the construction of reference standards.

5. Justify the existence of services and information systems

Determine the value, revealing that the system meets its objectives and that the products offered have a acceptable level of operational quality and meet the group of its intended users. Ie objective indicators showing the degree of user satisfaction, that the information provided improves the performance of its duties and  benefits for the organization.

1 Van House, Weil et al., (1990): Measuring academic library performance: a practical approach. American Library Association. Chicago