The study reports on a large-scale survey of pupils' perceptions of a good teacher in the Caribbean republic of Trinidad and Tobago. An essay-based, interpretive mode of research was used to elicit and identify constructs used by pupils between ages 7 and 17. The sample was a proportional, stratified, clustered, yet randomly selected representation of primary and secondary schools across the two islands. 1633 essays were content analysed and coded for age developmental comparison. Factor analysis showed no consistent underlying groupings of the 166 conceptual items by age, thus analysis was undertaken within logically constructed sets of items that are described: physical and personal characteristics of the teacher, quality of the relationship between teacher and pupil, control of behaviour by teacher, descriptions of the teaching process, and expected educational and other outcomes obtained by pupils due to teacher efforts. Results showed a general increase in number of conceptual items (and words per essay) by age, but this confuses four further criteria of item used. The four criteria were: age constancy, characteristics of younger pupils, characteristics of 11-13 year-olds, and characteristics of the oldest pupils. All ages perceived good teachers by physical presentation (clothing and appearance), teachers' care for pupils, descriptive teaching actions, and trustworthiness. Younger pupils focused on appearance, subjects taught, and assertion of physical punishment. Mid-aged pupils focused on the range of classroom control used by teachers (including distributive and retributive punishments), actions involved in the teaching process, and a growing awareness of the individual needs of pupils. Oldest pupils understood that good teachers must be well trained and highly motivated, should be sensitive and responsive to the needs of pupils, draw the pupils into the learning process, and have a major responsibility in preparing the pupil for the world of work and further education. Important aspects of the study show the link between pupils' conceptual reality and classroom environment, that pupils are very concerned about the relationship between themselves and teachers, and that the curriculum dominated approach to teaching does not meet pupil expectations.