TRANSDISCIPLINARY SKILL: Graphing
DEFINITION: a diagram showing the relation between variable quantities
STUDENT LEARNING OUTCOME:
Students are able to effectively communicate information using a diagram to show numerical relationships.
FORM / STRUCTURE IN APPLICATION AT NIS:
Drawing graphs by hand:
- Select appropriate graph to represent the data
- Choose appropriate tools used in construction – ruler, compass….
- Choose a suitable scale
- Label axes including units of measurement where necessary
- Use appropriate techniques to construct the graph – smooth curve for cumulative frequency, bars touching for histograms
- Write a specific and relevant title – ‘Graph to show…..’
- Check for clear presentation of features – ‘Is it easy to interpret/analyse?’
Strategies for Teaching and Learning:
Selecting the Most Appropriate Graph
- At the start of statistics based units represent the same data using a variety of graphs and discuss with students which is the most appropriate.
- Have students discuss the nature of different data (discrete v. continuous) and subsequently choose the most suitable representation (pie chart v. line graph).
- Students to study different magazines/newspapers and discuss why certain graphs have been used.
Role of Colour in Graphing
- Demonstrate the clarity of recognition that can be brought to graphing by the use of colour (e.g. showing a family of functions on the same Cartesian Plane.
- For Scatter plots: Have students collect data that shows a relationship between 2 variables and create one scatter plot as a class. Then discuss with students how a line of best fit should be drawn taking into account the ‘gradient’ of the plots whilst balancing the number of points above and below the line itself.
Graphing using Technology
The following software is generally used to graph data in these grade levels:
- Grades 5 – 8: Numbers (spreadsheet)
- Grades 9 – 10: Numbers and an introduction to LoggerPro and Geogebra (both for data collection and analysis)
- Grades11 – 12: Graphic display calculators as an IB-DP requirement