Science education in England
For the ages of 16, 17 and 18 (and older for those that remain in education below university-level), students in England do what is sometimes loosely called ‘key stage 5’ or KS5; it has no legal meaning (unlike the other key stages). And unlike KS1–4 in which the levels of complexity of topics learnt at each stage are prescribed within relatively narrow limits, at KS5, the levels of complexity of topics cover a wide range, although the highest level of complexity at KS5 is RQF level 3. Whether or not a student actually studies at this level of complexity in KS5 depends on his/her GCSE results—crucially on what subjects the student obtained passes at RQF level 2 standard (including mathematics and English) as well as the actual grades themselves. In other words, unlike KS1–4, where a specific student studies at one RQF level, at KS5, a specific student may be studying at several RQF levels depending on what s/he obtained at GCSEs. Regardless of the RQF-level mix, a KS5 student can do his/her post-16 study in one of the following:
Critical period hypothesis
Studies of deaf children learning American Sign Language (ASL) have fewer methodological weaknesses. Newport and Supalla studied ASL acquisition in deaf children differing in age of exposure; few were exposed to ASL from birth, most of them first learned it at school. Results showed a linear decline in performance with increasing age of exposure; those exposed to ASL from birth performed best, and 'late learners' worst, on all production and comprehension tests. Their study thus provides direct evidence for language learning ability decreasing with age, but it does not add to Lenneberg's CP hypothesis as even the oldest children, the 'late learners', were exposed to ASL by age four, and had therefore not reached puberty, the proposed end of the CP. In addition, the declines were shown to be linear, with no sudden 'drop off' of ability at a certain age, as would be predicted by a strong CP hypothesis. That the children performed significantly worse may suggest that the CP ends earlier than originally postulated. However, this decline in performance may also be attributed in part to limitations of second language acquisition for hearing parents learning ASL.