Abstract:
This research study explored the types of errors that Grade 11 learners make in trigonometric function graphs and the possible causes of these errors. The investigation was done in the quest for answers to these two research sub-questions: 1) Which types of errors do Grade 11 learners make in trigonometric function graphs? 2) What causes Grade 11 learners to make these errors? Brown and Skow’s (2016), Newman’s (1977), Oktaviani’s (2017), Radatz's (1979), and Smith et al.’s (1993) research were used to guide the deductive data analysis process of this study. The investigation was an exploratory case study conducted at three secondary schools in Tshwane, Gauteng Province-South Africa. Qualitative data were generated within the interpretive paradigm based on the researcher’s experience and insight into errors made in trigonometric function graphs. Thirty sampled learners' test scripts were analysed for error types, while fifteen of those learners were interviewed for possible causes of errors. Content analysis of the data generated from the test administered and the interview scheduled was done. There were 17 items in the administered test and were divided into four categories of concepts for the purpose of data analysis.
The findings from the test revealed that Grade 11 learners committed comprehension error in Concept 1 and Concept 3. It was further revealed that in Concept 4, encoding error was prevalent, lastly, misconceptions were notable errors in Concept 1 and 2. Also, this investigation identified the possible causes of these errors as: difficulties in obtaining spatial information; deficient mastery of pre-requisite skills, facts, and concept and the application of irrelevant rules or strategies.
