When non-experts learn new concepts, it is more effective for them to study step-by-step solutions to solved problems (worked examples) than to attempt solving problems. Worked examples are effective only when learners self-explain the solutions and when multiple, varied worked examples of the same concept are provided. Worked examples are most effective for non-experts (i.e. most of our students most of the time). Experts benefit more from attempting to solve problems than from studying worked examples.
Provide learners fully worked examples and require them to self-explain solutions through asking students follow-up questions (ex: ‘Why was this strategy used?’, ‘What principle is being applied and why?’), annotating solutions, identifying an error in a solution or asking students to compare solutions of two contrasting examples.
As learners become more expert with a concept, fade support by asking them to solve more and more steps within a problem.
https://openlearning.mit.edu/mit-faculty/research-based-learning-findings/worked-and-faded-examples
The worked-example effect is a learning effect predicted by cognitive load theory (Sweller, 1988). Specifically, it refers to the learning effect observed when worked-examples are used as part of instruction, compared to other instructional techniques such as problem-solving (Renkl, 2005) and discovery learning (Mayer, 2004). According to Sweller: "The worked example effect is the best known and most widely studied of the cognitive load effects" (Sweller, 2006, p. 165).
Worked-examples improve learning by reducing cognitive load during skill acquisition, and "is one of the earliest and probably the best known cognitive load reducing technique" (Paas et al., 2003). In particular, worked-examples provide instructions to reduce intrinsic cognitive load for the learner initially when few schemas are available. Extraneous load is reduced by scaffolding of worked-examples at the beginning of skill acquisition. Finally, worked-examples can increase germane load when prompts for self-explanations are used (Paas et al., 2003).
Renkl (2005) suggests that worked-examples are best used in "sequences of faded examples for certain problem types in order to foster understanding in skill acquisition," and that prompts, help system, and/or training be used to facilitate the learners' self-explanations. This view is supported by experimental findings comparing a faded worked-example procedure and a well-supported problem solving approach (Schwonke et al., 2009).
https://en.wikipedia.org/wiki/Worked-example_effect