Final answer:
The term 'Summer Slide' refers to the loss of reading progress experienced by students from lower-class families during the summer compared to their middle-class peers, contributing to the wider education gap.
Step-by-step explanation:
The phenomenon where students in lower-class families lose about 3 months of reading progress over the summer compared to their middle-class peers is known as the Summer Slide. This term describes a significant educational disparity that emerges when students do not have access to engaging educational activities or resources during the summer months, often due to socioeconomic barriers. Additionally, a lack of educational support, such as that which might arise from a strained home environment or limited access to technology, can exacerbate this issue, further widening the education gap.