On a magnificent June day, Canna Primary playground is a piece of Scottish educational heaven. “Playground” is perhaps pushing it. It is no more than a patch of rough, daisy-laden turf but it leads down to a white garden gate that opens on to a sheep-grazed shoreline.

Three girls, aged five, eight and nine - the entire school roll - play happily on swings and climbing frames during their lunchtime break amid the racket of birdsong. Vivid blues and greens confirm the season and a protected, sweeping bay with a distant backcloth of the jagged Cuillin Hills of Skye provides the finishing touches.

Only a week before, the island idyll was rather different. To stick your head around the corner of the 125-year-old cottage school would have been to tempt decapitation. Almost hurricane gusts burned brown the leaves of hedges and trees. Such are the extremes of this National Trust-run island, 25 miles west of Mallaig, which is home to 11 adults, the girls, sheep and cattle, countless gulls, the odd sea eagle and a Gaelic heritage.

To Joan Stephen, the head - and only - teacher, the end of term comes as a relief. It has been another hard year, strange though that may seem to others who might envy a class of three. Home and school are interchangeable. The ground floor has two main rooms, both about 15ft square, with a kitchen at the back. One room is a lounge, the other is a classroom, stacked with gear and the evidence of pupil efforts. The school office is a cubbyhole at the top of the stairs, between the main bedroom and spare room.

Like any other teacher Mrs Stephen is commanded to deliver the rich tapestry of the 5-14 curriculum, only in a limited setting. Given that there is no gym and no equipment, there is little scope for physical education. Running to school and avoiding storms constitutes the PE curriculum.

Mrs Stephen admits maintaining the property in the past year has driven her to tears. Heating has depended on a four kilowatt generator in the back sheds that has to be kickstarted each morning. Mrs Stephen says: “The generator is too small and in winter it can be freezing. We have two radiators but cannot turn them both on at the same time. If you want to spend time on the photocopier or computer, you have to turn off the heater temporarily.”

Her husband, Mike, a surgical dentist who regularly works in England, says temperatures inside the cottage rarely climbed above 50F last winter. The priority was heating for the children, which meant the clothes washing was confined to weekends. The faulty, coal-fired stove in the kitchen had also chucked smoke into the classroom.

Then there is the dodgy water supply, sourced from a spring. Despite eight feet of rainfall over the winter, it ran dry in May. These difficulties and a dispute between the National Trust for Scotland and Highland Council property managers led to a one-day protest closure of the school in May. The council refused to allow non-approved tradesmen to do essential work.

However, things are looking up, following the site visit of Highland’s education convener and director of education. The heating, water and accommodation problems are set to be resolved by relocating the school to a nearby house. Without a change, it would be impossible to absorb the pre-school pupil the year after next.

Professionally, the loneliness of the remote teacher sometimes gets to Mrs Stephen. She has been on Canna for four years and went two years without a visit from anyone - partly because of the travel difficulties. E-mail and the Internet are proving invaluable, despite problems with telephone links and power supplies. “I love being on e-mail,” says Mrs Stephen. “It’s the best thing that’s happened to this school.”

Face-to-face contact remains essential, however. “One of the difficulties of being in this situation is that you begin to lose perspective about how you’re doing your job,” says Mrs Stephen, so she has established a peer support system with Eilidh Klemm, head of Inverie Primary in Knoydart.

But there are many plus points. “As the girls breathe, you see them grow and learn,” says Mrs Stephen. “You see the whole learning process straight in your face. You can see with individualised learning how rapidly they develop in basic skills. They make phenomenal progress.

“I think what they miss out on are the social skills, the learning with other children. That’s why I place high priority on personal and social development, making them aware of themselves, raising self-esteem and confidence, and an understanding of where they are,” Mrs Stephen explains.

In equally remote Knoydart, on the mainland, Mrs Klemm shares similar views. She came with her family from Germany 20 years ago and taught her two children at home until they went to secondary school. She then qualified as a primary teacher and took over at Inverie four years ago.

She has to trek over rough ground for 15 minutes before picking up a rough track and driving 30 minutes to an equally dilapidated building which is school to six pupils, aged five to 11, and from August will also squeeze a nursery pupil and auxiliary into the one classroom.

Mrs Klemm says: “The children are getting a wonderful education and it’s a wonderful job. What you can achieve with a small number of pupils is so much more satisfying than with a class of 33. But my life would be so much easier if there was better accommodation.

“There are only six pupils but you’ve got to provide the right education and atmosphere so that you can have hardworking P7s on the computer, peace and quiet to work on research aspects and still give the younger ones activity-based lessons, including singing. It would be nice to have some place to separate them at times.

“There’s also the telephone ringing in the same room but there is no place to talk to parents in private; no place for pupils cooling off. They’re on top of each other all the time.”

Activities are whole-class based but at different levels. Mrs Klemm enjoys being responsible for all the subjects, the creativity and the natural environment they live in. Nevertheless, she is relishing the summer break.

“People should realise there is stress because of the small numbers. I’ve got all different levels in the same class and you’ve got to get them socially working together. If there is any unhappiness in one child, the whole school is affected and that can require a lot of tact.”

Six curriculums means a lot of paperwork, Mrs Klemm says, and every year topics have to be refreshed. Isolation also produces its own pressures, not least of which is the absence of staff discussion and feedback.

Iain Wilson, the school board chairman and also hill farmer, boatman, stalker, salmon fisherman and holiday lodge manager, has a son and daughter at the school and knows its value. “It’s not purely a school. The community are involved in things while the children can give a lot to the community,” he points out.

Mrs Klemm says: “In some ways the children are very mature because they’re used to talking to adults and mixing with people. In a lot of ways it’s an ideal childhood because of the fruitful exchange between home, school and the environment.”

On Rum, an island run by Scottish Natural Heritage, primary headteacher Chrissie MacDougall has seven pupils, yet she is sent all the circulars and education bumph that any large school receives.

“I think a little less bureaucracy and filling in of reports would make my job a lot easier,” she says. “I’m not joking; my post comes in a mailbag.

“I love my children. Let me get on with that,” she protests.

Mrs MacDougall, who has taught in the Lochaber area for 30 years, has been buffeted by more than documents and organisational change this year. January gales blew in her school cottage window, showering her lounge in glass and papers.

Bruce Robertson, Highland’s director of education, backed by a fresh political drive, is aiming to improve the prospects for these fragile schools, not least by renovating the unacceptable buildings and accompanying school houses. Councillors now accept these communities have had a raw deal.

Remote, single-teacher primaries have to be made as attractive as possible to overcome the movements of families and teachers that can result in rapid changes of fortune. “In an urban area you can plan fairly accurately, but in these communities all you need is one or two families to move and your planning goes up in smoke,” Mr Robertson says.

Staffing has been, and will remain, a problem since levels of teaching commitment go way beyond normal levels of professionalism, Mr Robertson adds.

The isolation is compounded by the often inclement weather. On a fine day in June, life is idyllic. In a January gale, when the islands can be cut off for two weeks, it’s quite another matter.