Pupils’ understanding of probability & statistics (14-15+) difficulties and insights for instruction

Abstract

This study highlights pupils’ common errors and misuses of probability and statistics. Four hundred pupils, aged 14-15+, attending a number of Maltese non-selective (mixed-ability) schools were given a ‘Probability & Statistics’ test. Interviews were also conducted to inform and interpret the results of the written test. The report highlights pupils’ difficulties in the drawing of simple inferences from tables and statistical diagrams, in understanding ‘equally likely’ situations, in categorising data, in distinguishing between bar charts and histograms, in finding probability for simple and combined events, in summarising data and in choosing a suitable average. Faulty intuitions (e.g. the ‘gambler’s fallacy’, the law of averages) and misconceptions (e.g. the ‘sample space’ misconception) were also evident. The implications for teaching in the light of the present findings are discussed.