Deductive and inductive reasoning
Deductive reasoning is essentially a top-down approach which moves from the more general to the more specific.It is also possible that during the process, the learner may arrive at an incorrect inference or produce an incorrect or incomplete rule.Some course books may adhere to one approach or the other as series style, whereas some may be more flexible and employ both approaches according to what the language being taught lends itself to. Most inductive learning presented in course books is guided or scaffolded.Inductive reasoning is more of a bottom-up approach, moving from the more specific to the more general, in which we make specific observations, detect patterns, formulate hypotheses and draw conclusions.A deductive approach involves the learners being given a general rule, which is then applied to specific language examples and honed through practice exercises.An inductive approach involves the learners detecting, or noticing, patterns and working out a 'rule' for themselves before they practise the language.However, the learner-centred nature of inductive teaching is often seen as advantageous as the learner is more active in the learning process rather than being a passive recipient.deductiveinductive

Deductive and inductive grammar learning
These two approaches have been applied to grammar teaching and learning.jonhird1 jonhird2
Q: Skills for Success Listening and Speaking Level 3                        New Headway 4th Edition (Elementary)

Which approach - pros and cons?This could also promote the strategy of 'noticing' in the student and enhance learner autonomy and motivation.