Geometric Constructions Assessment Error Analysis
Lesson 13 of 13
Objective: SWBAT Analyze and correct common errors on the Geometric Constructions End of Unit Assessment
At the beginning of the lesson, I have students answer the following question, "What strategies can be used to decide on the correct answer to a multiple choice question?"
After about three minutes of thinking time, we discuss their responses and some techniques for answering multiple choice problems and solving problems in general. Some common responses to the question are: "Read the questions and ask, 'Does my answer make sense,'" "Eliminate responses you know are wrong." and "Draw a picture to represent the problem."
Students work in pairs to identify and correct errors on selected test questions. On the front of the worksheet, there are 8 multiple choice questions. Four answers are correct and four are incorrect. Students decide which ones they think are correct and justify to each other why.
On the back of the sheet, students are given three constructions, which were performed incorrectly. Students describe the error and then correct the error. These errors are general and are based on common misconceptions of my students as demonstrated on their assessments. As the students are working, I remind students to refer back to their notebooks where they have correct examples and compare them to the constructions on the sheet.
At the end of the class, we go over the errors on the sheet. I call on a few students to describe the errors they found and explain how to correct them.
Questions 1, 5, 7, and 8 are answered incorrectly on the sheet. In question 9, the "student" has used arcs with two different radii to construct the bisector. The "student" in question 10 has left out the last step of the construction and has drawn an arbitrary line through point P that appears to be parallel to line AB. Although there were several options for answering question 11, the "student" constructed a rectangle and not a regular polygon.