Informal evaluation aims at eliciting performance without recording results. It is a way of letting learners know how they are doing while motivating them to carry on. It can take the form of unplanned verbal comments on a learner's performance, as well as coaching during the learning process. Some examples are: "Good work!" and "You mean you 'broke' the window, not 'break' the window."
Formal evaluation consists of planned procedures to give an appraisal of a learner's achievement. It can take the form of tests, portfolios, journals or systematic observations of a learner's performance.
Formative evaluation determines learners' acquisition in each stage of a learning situation to see whether they are on the right track toward their goals. Teachers can proceed as planned from the evaluated point or make the necessary changes to achieve the desired results.
Summative evaluation takes place when the activity is finished. Its purpose is to evaluate the results learners obtained from the whole learning situation and determine whether they reached the initial objectives. The results of a summative evaluation give the teachers a measure of their own work and sometimes draw their attention to the necessity of improving their evaluation techniques.
Self-evaluation, one of the foundation stones of successful learning, improves students' autonomy. It also develops intrinsic motivation--a self-driven desire to improve--that leads to successful acquisition. Learners discover what they know and don't know yet through self-evaluation. They are now able to set their own goals and use their newly acquired knowledge about themselves to reach these goals. On the other hand, peer-evaluation within a team develops cooperative learning and self-confidence, improving the quality of each member's work.
In addition to measuring how much students have acquired from a particular program or activity, evaluation can also show learners where they are and where they should be in terms of knowledge acquisition. Evaluation results can give them an idea of how well they did and what aspects of their work they should improve or develop. The results also motivate them to continue learning and provide them with a formal recognition of their work.