External and internal evaluation It is also possible to distinguish between external evaluation and internal evaluation. External evaluation. This is evaluation that is carried out by someone who is (or was) not directly involved in the development or operation of the system being evaluated, ie by someone from outwith the project team. Clearly, such an external evaluator has a number of advantages, bringing (it is to be hoped) objectivity, lack of vested interest, and the ability to look at matters from a fresh perspective. An external evaluator also has a number of disadvantages, however, most of which are related to relative value systems and to the lack of involvement the evaluator has had in project-related decisions. Such an evaluator may not, for example, fully appreciate why the development team chose to act in a particular way, or appreciate the thinking that lay behind certain decisions. The project team may also feel threatened by the evaluator, and feel that alien values or a negative, 'nit-picking' approach are being adopted. Internal evaluation. This is evaluation that is carried out by someone from the actual project team. Clearly, such an evaluator has the advantage of understanding fully the thinking behind the development, together with an appreciation of any problems that may have arisen, and should also command the trust and cooperation of the other members of the team. On the other hand, such an evaluator may find it difficult to make any criticisms of the work carried out, and, because of their close involvement with the project, may be unable to suggest any innovative solutions to such problems that are identified. Such an internal evaluator will know only too well how the members of the group have struggled to produce their course, curriculum or package, and may shrink from the thought of involving them in more work.