Reducing extraneous cognitive load in mathematics instruction Split-attention effect G B/60°=110°50° dure for finding And x 11.° Figure 2, Integrated geometry problem and solution Anale x· Ante DBE ( ve gure 1. Conventional geometry problem and solution. Split attention situations: learners have to mentally integrate multiple sources of information and this integration overburdens limited working memory capacity
Reducing extraneous cognitive load in mathematics instruction Split-attention effect Split attention situations: learners have to mentally integrate multiple sources of information and this integration overburdens limited working memory capacity
Split-attention situation a diagrams accompanied by textual statements a neither text nor diagrams are intelligible in isolatⅰon a understanding requires searching and matching elements from the text to the appropriate entities on the diagram and their mental integration a applies to any two or more interdependent sources of information (text and text text and tables etc a Split attention effect: physically integrating corresponding sources of information within instruction may reduce extraneous cognitive load
diagrams accompanied by textual statements neither text nor diagrams are intelligible in isolation understanding requires searching and matching elements from the text to the appropriate entities on the diagram and their mental integration applies to any two or more interdependent sources of information (text and text, text and tables, etc.) Split attention effect: physically integrating corresponding sources of information within instruction may reduce extraneous cognitive load Split-attention situation
We assume that the tool is located at the origin. Firstly, we have to instruct the machine to quickly go to the point A. The NC command for a quick movement without cutting is G00 and is denoted with a broken line. We also have to instruct the machine where to go. Point a has the absolute position (20, 30). The nc command for a movement to the point a is X20 Y30. The complete command for this movement is therefore G00 X20 Y30. A straight line cut from a to B is required. The NC command for a straight line cut is GOl and is denoted by an unbroken line. We now have to instruct the machine to cut to point B. To achieve this the NC command for the point b is required. The NC command for point b is X-20 Y10. The complete command for this movement is GO1 X-20 Y10. The NC com-mand to return the tool back to the origin is simply Go0 XO YO. This completes the NC program code for this job B workpiece
We assume that the tool is located at the origin. Firstly, we have to instruct the machine to quickly go to the point A. The NC command for a quick movement without cutting is G00 and is denoted with a broken line. We also have to instruct the machine where to go. Point A has the absolute position (20, 30). The NC command for a movement to the point A is X20 Y30. The complete command for this movement is therefore G00 X20 Y30. A straight line cut from A to B is required. The NC command for a straight line cut is G01 and is denoted by an unbroken line. We now have to instruct the machine to cut to point B. To achieve this the NC command for the point B is required. The NC command for point B is X-20 Y10. The complete command for this movement is G01 X-20 Y10. The NC com- mand to return the tool back to the origin is simply G00 X0 Y0. This completes the NC program code for this job. -Y -X X Y workpiece A -40 -30 -20 -10 10 20 30 40 40 30 10 -10 -20 -30 -40 20 B
Chandler and Sweller. 1992 Follow the numbered steps 7 A straight line cut from a to B is 6 The complete command for this required movement is therefore Go0 X20 Y30 8 The NC command for a straight line cut is G01 and is denoted by 5 Point A has the absolute position(20, 30) an unbroken line The nc command for a movement to the point A is X 20 Y30 9 We now have to instruct the machine to cut to the point B 4 We also have to instruct the machine where to go 10 To achieve this the nc command for the point B is required. 3 The NC command for a quick movement without The Nc command for the point B is cutting is Go0 and is denoted with a broken line X20Y10 10 1 The complete command for this 2 Firstly, we have to instruct the machine movement is G01 X-20 Y10 to quickly go to the point A 10 12 The Nc command to return the 1 We assume that the tool is tool back to the origin is simply located at the origin G00 XO YO porkpie
Y Follow the numbered steps -X X workpiece A -40 -30 -20 -10 10 20 30 40 40 30 10 -10 -20 -30 -40 20 B -Y 2 Firstly, we have to instruct the machine to quickly go to the point A 3 The NC command for a quick movement without cutting is G00 and is denoted with a broken line 4 We also have to instruct the machine where to go 5 Point A has the absolute position (20, 30). The NC command for a movement to the point A is X 20 Y30 6 The complete command for this movement is therefore G00 X20 Y30 10 To achieve this the NC command for the point B is required. The NC command for the point B is X-20 Y10 11 The complete command for this movement is G01 X-20 Y10 7 A straight line cut from A to B is required 9 We now have to instruct the machine to cut to the point B 8 The NC command for a straight line cut is G01 and is denoted by an unbroken line 12 The NC command to return the tool back to the origin is simply G00 X0 Y0 1 We assume that the tool is located at the origin Chandler and Sweller, 1992