COMPLEMENTARY EVENTS IN PROBABILITY: EXPLORATION BY PROSPECTIVE PRIMARY SCHOOL TEACHERS

Abstract

The article presents a study with students, prospective primary school teachers, about complementary events, based on the objectives: 1) to verify if two given events are complementary or not; 2) to state the definition of complementary events; and 3) to formulate examples of complementary events. Participated in the study 37 students of the 2nd year of the Degree in Basic Education, who attended a university in the north of Portugal. The data were obtained through the application of a questionnaire with several tasks about different types of events, and in the study the data resulting from the answers given by the students to only one task with four items, involving the classification, definition and formulation of complementary events were used. In terms of results, it is noteworthy that more than half of the students were able to classify events as complementary or non-complementary and formulate examples of complementary events, but very few adequately justified their answers. Students, on the other hand, had more difficulty in defining complementary events, with about one in three enunciating the definition correctly. However, even students who presented correct and complete definitions had difficulty in applying these definitions to justify the classification of events in complementary or non-complementary and the exemplification of complementary events, which highlights the need for students to practice such justifications.