Philippe Dupasquier’s original illustrations for Anne Fine’s Bill’s New Frock took their cue from the text, and depicted a lightweight, little number, with tight cuffs and frilly tucks round the waist. The cover for the Teachers’ Guide which accompanies the new Channel 4 adaptation of the story, screened as part of its Book Box series, uses the original book-jacket illustration. But the screen frock is a very different affair: the colour of pink highlighter and made of heavy upholstery material. During the opening credits it comes careering through the air, arms akimbo, and envelops Bill in its folds.

Andrew Davies, in a typically forthright and sure-footed screenplay, has vamped up those aspects best suited to the screen, and omitted those better left to the subtleties or discursive opportunities of narrative text. Out, for example, go the “wumpy choos” (1p chews), and the lengthy sequence at the end of the book in which a group of girls attempt to conspire with Bill to allow a sporting no-hoper to win a running race (an important sequence in terms of the book’s treatment of male and female sensibilities) is exchanged for a brief session of indoor PE.

In the book, Bill wakes up one morning to find himself acknowledged as a girl. The extent of his transformation is given anatomical certainty in the television adaptation. Bill goes to the toilet and looks down in anguish when he opens up his pyj-ama trousers. The target audience of seven to nine-year-olds will love this, as will their teachers the uncomfortably accurate depiction of morning assembly.

During the day, Bill’s experiences at school become object lessons in gender differentiation. Davies retains in his screenplay the teacher’s different responses to untidy work, but on balance the gender issues are less evident in his version. The emphasis - from the moment he discovers that change down there - is more on Bill’s experiences as nightmare, although the video-Bill is never as outcast as the Bill-of-the-book.

Astrid, a minor character in Fine’s story, is given a key role in the TV programme as the classroom feminist with whom Bill strikes up a chummy relationship. He also has a little sister’s hand to hold when he runs the gauntlet of Mean Malcolm and Sean Scab, the leering yobs who wolf-whistle in the book, and in the film make crude lip-licking gestures. Bill’s triumphant line, after he has successfully pushed Malcolm backwards into a dustbin - “Whistle at dogs in future, not at people” - is disappointingly passed over by Davies. Nor is it easy to see why, in the sequence when Bill is made to carry an ever-increasing load to the school office, the little bottles of coloured ink have been replaced by tiny bottles of poster paint, of a type used by children at home, but never purchased in such tiny sizes by schools.

These are trifling quibbles, however, when put beside the general impact of a boldly entertaining two-part production, which features Josie Lawrence in a cameo role as Bill’s mum, gives Daniel Lee a chance to shine fluorescently as Bill, and provides several other striking performances. The series takes as its guiding principle the curriculum requirements of 7 to 11-year-olds to study some books in considerable detail.

These two programmes, together with the Teachers’ Guide, are best viewed as accessories to Fine’s original story. The book and the production are both described as being appropriate for seven to nine-year-olds, but older children can enjoy them too. They will certainly enjoy the television transmissions, and many of the activities suggested in the guide are really more appropriate for Years 5 and 6. For example, Activity Sheet 5 presents the opening lines of the book beside the first part of Andrew Davies’ script: “Children should be asked to discuss the differences and the effectiveness of each approach.”

Although Channel 4 lists its Web address inside the cover of the guide, teachers will be disappointed to discover that no supplementary materials are yet available on-line. A pity. Downloadable multimedia resources - a video grab of the opening sequence, for a start - could be used to support the higher-level media studies proposed in the guide.

Teachers’ Guide #163;3.95 from Channel 4, PO Box 100, Warwick CV34 6TZ. Bill’s New Frock is published by Mammoth, #163;3.50