In the education of his children, he had already learned the value of the observation of children’s ways and mental states.  Having found that Rousseau’s system was imperfect, he was groping after some better method.  His daughter writes:  ’Long before he ever thought of writing or publishing, he had kept a register of observations and facts relative to his children.  This he began in the year 1798.  He and Mrs. Honora Edgeworth kept notes of every circumstance which occurred worth recording.  Afterwards Mrs Elizabeth Edgeworth and he continued the same practice; and in consequence of his earnest exhortations, I began in 1791 or 1792 to note down anecdotes of the children whom he was then educating.  Besides these, I often wrote for my own amusement and instruction some of his conversation-lessons, as we may call them, with his questions and explanations, and the answers of the children. . . .  To all who ever reflected upon education it must have occurred that facts and experiments were wanting in this department of knowledge, while assertions and theories abounded.  I claim for my father the merit of having been the first to recommend, both by example and precept, what Bacon would call the experimental method in education.  If I were obliged to rest on any single point my father’s credit as a lover of truth, and his utility as a philanthropist and as a philosophical writer, it should be on his having made this first record of experiments in education. ...  In noting anecdotes of children, the greatest care must be taken that the pupils should not know that any such register is kept.  Want of care in this particular would totally defeat the object in view, and would lead to many and irremediable bad consequences, and would make the children affected and false, or would create a degree of embarrassment and constraint which must prevent the natural action of the understanding or the feelings. ...  In the registry of such observations, considered as contributing to a history of the human mind, nothing should be neglected as trivial.  The circumstances which may seem most trifling to vulgar observers may be most valuable to the philosopher; they may throw light, for example, on the manner in which ideas and language are formed and generalised.’

Edgeworth and his daughter Maria brought out their joint work, Practical Education, in 1798.  Maria adds:  ’So commenced that literary partnership, which for so many years was the pride and joy of my life.’  We who were born in the first half of the nineteenth century can remember the delight of reading about Frank and Rosamund, and Harry and Lucy, and feel a debt of gratitude to the writers who gave us so many pleasant hours.