Distinquishing Characteristics During Formal Operations * Proportional reasoning * Ability to think about the unseen * Ability to consider a range of possibilities [Understands the concept of the possible, as in moral dilemmas, justice, understanding of self, vocational aspirations] * Approach problems systematically, as in the ability to make a prediction, revise thinking (given new evidence), and revise and improve a disconfirmed hypothesis. * Thinks logically: Understands and uses principles of scientific thinking (e.g., inference, deduction, hypothesis-testing, ruling out alternative hypotheses)

 "Form" in Formal Operations Whereas the concrete operations child follows the content of an argument, the formal operations child can follow its form. For instance, contrast the content versus the form in the appreciation and interpretation of a parable, metaphor, or satire (e.g., Animal Farm, Gulliver's Travels) Real versus Possible As the adolescent develops formal operations, his or her construction of reality becomes more precise and an awareness of gaps in understanding emerges. These gaps are filled with tentative hypotheses about what might be true. These hypotheses, once proposed, are then put into shape to test their validity. Based on the feedback from an observation or experiment, some hypotheses are confirmed, others are revised and put into shape for further testing, and others are rejected. Systematic Problem Solving Concrete operations children use trial-and-error problem solving. Give them a problem with multiple combinations (e.g., a chemistry lab experiment) and they will test one combination after the other fishing for an answer. With formal operations, the adolescent thinks through problems mentally and abstractly. He or she will envision (predict) a possible course of action, test it in some way, and then use logic to reason through what the likely, upcoming consequences of that predicted course of action will be. The thinking is systematic, and it is supported-once data are collected-by inference, deduction, and reflection. Systematic means the formal operations adolescent will make a prediction of what is likely to occur, test that prediction in some way, notice what actually happens (what the data, not the hypothesis, says), and then attempt to isolate the cause behind what actually occurs. The approach is a bit like Sherlock Holmes-work to isolate all possible causes and test each one in a systematic fashion, starting with the most likely, preceding to the next most likely (given the evidence obtained so far), and continuing systematically. Hypothetico-Deductive Logic Using a general law to make a situation-specific prediction. For example, all reinforcers increase voluntary behavior (a general law). Then, what effect will a teacher's praise have on a child's hours of reading behavior? One starts with a general law, makes a situationally-specific prediction based on that general law, and then designs an experiment to test that prediction in the specific situation (to see if the general law applies to the specific situation).