* Infants: For infants, "challenging" might mean exploring different textures, sounds, and sights. "Achievable" means tasks within their motor skill capabilities – grasping a rattle, tracking a moving object, or turning their head to follow a sound. These experiences stimulate brain development, build crucial neural pathways, and foster a sense of agency and self-efficacy.
* Older Children: As children grow, the challenges become more complex, involving problem-solving, language acquisition, social interactions, and abstract thinking. The key is to maintain a balance: tasks should be challenging enough to extend their abilities but not so difficult as to be frustrating or discouraging.
The crucial element is the appropriateness of the challenge. An overly simplistic task won't stimulate growth, while an overly difficult one can lead to frustration and avoidance of learning. The experience needs to be within the child's "zone of proximal development" – the space between what they can do independently and what they can do with guidance and support.
Therefore, while the principle applies across all ages, the *implementation* of purposeful, challenging, and achievable learning experiences must be tailored to the child's individual developmental stage and abilities.