The grade awarding process is claimed to bring students' performances to a common denominator so that one can argue that a grade A on one examination is equivalent to a grade A on another examination (Wilmott, 1994). At the time of my data gathering GCSE groups were not required to provide 'profile reporting' by Attainment Targets. This means that the components (biology, chemistry and physics) in GCSE Double and /or Single Award Science were not individually graded - they may have existed in a notional form, but were not formally stated nor for all grade boundaries (Newbold, 1995) (in 2008 grades for biology, chemistry and physics components exist for co-ordinated science but not for integrated science syllabuses). If they had, it would have been of help in considering the relative performances in the separate sciences within Double and Single Award Science. Without that grading, there would be little value in comparing marks on the components (ibid.). Consequently, I decided to focus only on the three sciences as separate GCSE subjects in Triple Award GCSE Science.
This was an appropriate decision in terms of the associated student population. At the time of my research, schools in England, not uncommonly, entered their students for different separate science subjects with different GCSE examination groups (Newbold, 1994, personal
communication). This situation makes for incomplete data that would be problematic for my selecting separate science GCSE as the basis of my study. All state schools in Wales are registered WJEC examination centres. Consequently the vast majority of young people in Wales are prepared for WJEC’s GCSE examinations and this avoids problems of incomplete data.
I also decided that it would be more informative to compare the performances of those students who had taken all three o f the separate GCSE science subjects than compare the
GCSE biology, chemistry and physics. In the latter case, comparing the achieved means for biology, chemistry and physics candidatures would not really address the issue of whether students' are more severely graded in one subject than another. Therefore, my focus was only on those students who had attempted three science subjects in Triple Award GCSE Science.
Students are entered for their GCSE biology, chemistry and physics in terms of particular tiers. For example, in the 1995 examination session, the separate science subjects were offered in three tiers, with only one giving access to the top three grades (A*, A and B). I considered it
on those students who had attempted an option in each science subject that gave access to the same grade range. Otherwise, comparisons would be made between a students' grades on say, biology examination papers offering access to grades A*-C, with chemistry examination papers only offering access to a maximum of grade C. Such disparities in students' separate science tier entries are not uncommon (WJEC, 1994, personal communication) because teachers perceive their students as having differential abilities in the separate science subjects and select tiers for their students to match those perceptions.
This entry factor, that to an extent prejudges the performance of students, was seen to reduce the validity of this comparability study. I sought to explore assessment artefacts between papers across subjects. I did not wish to add to that factors which might arise between papers within a subject as previous subject-pair comparisons had done but without due consideration for validity issues (NEAB, 1993; UCLES, 1994). By focusing only on those students who had attempted GCSE biology, chemistry and physics in a tier giving access to the same grade range, this potential source of invalidity was taken into account as far as was possible. No other published GCSE science comparability study had controlled for this variable. The tier chosen was the one that offered students access to the top four GCSE grades. This tier was chosen as in my experience, and confirmed by NEAB and UCLES personnel (ibid.), it is generally only those students who are considered capable of the top GCSE grades that are entered for all three separate science subjects. Furthermore, students entered for any tier of WJEC’s GCSE separate sciences come largely from state rather than independent schools unlike the situation with some English GCSE examining groups at the time of this research (Newbold, 1995, personal correspondence). In selecting the tier giving access to the top GCSE grades in the separate science GCSE examinations for my
comparability study, the associated student population would remain representative of the WJEC GCSE examination population as a whole in terms of examination centres. The 1995 examination session saw a different allocation of awarded grades to tiers than for the two previous years. Consequently to cover the same grade range as for the 1993 and 1994 examination sessions, students were considered who had attempted tier 03 (option R) with its expected grades B-A*, in addition to and separately from those students who had attempted tier 02 (option Q) with expected grades B-E.
During the grade awarding process, students whose scores correspond to grades other than those allocated to their entry tier range may be allocated an exceptional grade to allow for
‘mistakes’ in tier entry. For example, if a student entered for tier 02 offering grades B-E achieves an examination score equivalent to that required for grade A they may be awarded a grade A as an exceptional case. Similarly, a student entered for tier 02 might only achieve a score just below that required for grade E and so be awarded grade F as an exceptional grade. For tier 03 a grade C might also be awarded to students whose achieved scores do not equate to the grade range A*-B. Consequently, when dealing with and interpreting the grade outcomes of the study’s WJEC 1995 examination sessions the existence of exceptional grades needed to be considered. The other WJEC and SEG examination sessions i.e. 1993 and 1994 did not have overlapping grade tiers and thus, exceptional grade awarding did not occur.
Therefore, the WJEC population that was identified included students who had attempted all three of the WJEC separate GCSE subjects, biology, chemistry and physics, in the tier giving them access to the top GCSE grades, namely tier 02 (grades A-U) in 1993 and tier 02 (grades A*- U) in 1994. For 1995, students who had attempted these GCSE science subjects were considered in two separate groups, namely those who had sat tier 02 in all of these science subjects and then for the same subjects, those who had sat all tier 03s. When looking across examining groups the SEG examination population was selected to match as closely as possible that for WJEC in the terms outlined above. The number of students within these identified WJEC and SEG populations for the examination sessions ranged from a minimum of 387 to a maximum of 1761.