However, three pilot projects in North Lanarkshire, East Ayrshire and Glasgow appear to have had a positive impact.
An evaluation report for the Scottish Executive by Ruth Bryan and Morag Treanor from the MVA Consultancy, shows improvement in attainment, although not consistent across all areas. Teachers were also convinced that the pilots benefited pupils by helping them cope socially with the transition to secondary
North Lanarkshire literacy pilot
Initially, three secondary schools and their associated primaries, ran projects led by a literacy development officer (LDO) whose role over two years was to contribute to English teaching in S1 and S2, and spend time in the primaries.
One of the projects was discontinued because English teachers at the school did not feel the LDO (a learning support teacher in this case) was sufficiently qualified, and the appointee suffered from illness early on.
The problem underlined the importance of making the right appointment. The pilots continued in Cumbernauld High and Brannock High in Motherwell (and their associated primaries).
The idea behind putting the LDOs into primaries was to allow teaching methodologies, such as co-operative learning, to be shared and to improve the cross-sector transfer of teaching and learning information. The LDOs also introduced "reciprocal reading", which is conducted in small groups with each pupil taking on a different role linked to the strategies used - predicting, clarifying, questioning, summarising and visualising.
Partly because of lack of space, the literacy development officer in one school concentrated on working with S1 and S2 classes, whereas the second school's LDO did more work with separate groups. She focused on topics such as the writer's craft with the higher ability groups in S2, allowing class teachers to spend more time with lower ability pupils.
The support teachers produced a range of materials for pupils and took responsibility for assigning, assessing and providing feedback on their work. The budget for the pilot also allowed the LDOs to spend more money on new technology, such as interactive digi-text materials for use on a smartboard. These materials were also used in the primary schools.
One of the LDOs led an inter-departmental focus on literacy, so that the school had a clear correction code for spelling, grammar and punctuation, which was laminated and displayed in every classroom. The other gave writing frames to science, humanities and maths departments to "get language across the curriculum".
In the primary schools, the LDOs did team teaching, with one taking pupils out of class to focus on story writing with different ability groups. They also helped primary teachers with marking, so that pupils could get used to the standard and marking procedures of secondary school.
The report said secondary teachers frequently reported the benefits of the LDOs having time to conduct research, provide materials, help plan lessons, and monitor and administer national assessments. "The LDOs were a 'big support' to their departments, particularly because of their experience as ex-APTs (assistant principal teachers) in English, which meant they knew 'how to make the smallest changes for the biggest effect'," the report states.
"Teachers felt that having experienced staff to share their workloads reduced their stress and enabled them to introduce initiatives such as co-operative learning that would have been 'pie in the sky' otherwise."
One literacy development officer noted that, while primary pupils were taught in groups based on ability, secondary teachers expected the whole class to be at the same level. To understand the varying abilities in each class, the LDOs took P7 pupils' jotters to the secondary schools so teachers could see the standards achieved.
East Ayrshire numeracy pilot
This was carried out in two learning partnerships. One was led by the authority's smallest secondary, Doon Academy, in a former mining area of rural deprivation; the other by one of the largest secondaries, Grange Academy in Kilmarnock.
The format was that a primary teacher and a secondary maths teacher were employed to teach in each other's sector. The project provided funding for supply cover for other primary and secondary teachers to do cross-sector work.
Primary and secondary staff from both sectors worked together to produce a programme of study covering levels D and E, providing consistent practice in maths teaching and more detailed pupil profiles. A similar programme of study is currently being produced to cover level C.
Initially, there was staff resistance to sharing practice with other professionals. Some primary staff did not feel comfortable with teaching all aspects of the maths curriculum, so did not want a maths specialist.
Key ingredients for success were the support of heads, clear communication of the aims and methods, and strong working relationships across the sectors.
In both learning partnerships, the secondary maths teacher taught S1 and S2 classes, visited associated primaries and released other secondary teachers to visit the primary schools. In the Doon Academy partnership, the primary teacher, while in secondary, focused on whole-class teaching, whereas the focus in the Grange Academy partnership was on observation and team teaching.
Most of the secondary teachers extracted ability groups from primary classes and worked with them. They were able to push on the highest ability groups. One, who worked with level A and B pupils, said: "That was a shock, because we don't get many children of that ability (in secondary)."
The secondary maths teachers also tended to focus on interactive maths and used ICT. Primary pupils found it motivating to use Promethean boards - a more active form of learning than textbooks.
"The numeracy pilot highlighted a discontinuity between the primary and secondary sectors, namely the inconsistency of maths languages between the two sectors," the report added. "All the secondary teachers in both learning partnerships noted that the primary teachers were using language they would not, or not using language that they would, to describe maths problems."
One secondary teacher said: "We have found that, while the primaries have taught something that we do, the language has been a bit different so the kids don't recognise it. We talk about the x-axis, y-axis and origin, and the children haven't been taught this in primary. Now we can say: 'This is what you've been doing in primary and this is where we're going to take this forward'."
Enable at Eastbank Academy, Glasgow
The Enable project - Eastbank network for academic, behavioural and learning education - differed from the other two cross-sectoral pilots in that it was confined to the secondary school and focused less on curricular continuity.
It targeted the most vulnerable and least-able pupils only, employing primary trained teachers to concentrate on "back to basics" literacy and numeracy skills in S1 and S2 for two hours a day, rather than focusing on picking up where they had finished in P7.
The primary-based approach focused on social and pastoral care, as many of the pupils were emotionally immature.
This pilot had some elements of cross-sector liaison, chiefly through the information gathered about P7 pupils in order to place them in Enable classes. The project also introduced some co-operative teaching between the primary-trained Enable teachers and other secondary staff.
This project had the greatest potential for stigma to be attached to the pupils. Teachers were careful to address this and no pupils reported feeling stigmatised; not all pupils were aware they were part of an ability-based class.
The study found, however, that this raised issues about openness and honesty, and the implications of disclosure by pupils who did know what the Enable class meant.
Parents had to be more involved, as they had to give permission for their child to be placed in an Enable class. It was found easier to involve them in school hours than traditional parents' evenings.
Staff reported that the Enable pupils were better prepared for S3 than they would have been without the programme, and attainment data for the 121 pupils who took part in the first three years showed improvements in reading, writing and maths.
Pupils in mainstream S1 and S2 classes also benefited from the reduction in class sizes.
The full report can be found on www.tes.co.ukscotland