Describing and Explaining Patterns of Data in Graphs

Graph Layout Dependent variable Independent variable When you describe patterns on graphs you are describing how the dependent variable changes in relation to the independent variable

Example 1 Describing the pattern: Skill level at football The longer people train the higher their skill level Time spent training

Example 2 The temperature of the water decreases with time. As this is a curve shape you must also describe this Temperature of water °c Time mins It falls quickly at first but then goes down at a slower rate

Try Describing these Number of bubbles produced by yeast in 1 min Speed m/s Temperature ⁰c Time s

Explaining Graphs • When you explain what a graph shows you are using your science knowledge to explain why the results show the pattern they do. • There will usually be 2 or 3 marks for these questions

At lower temperature the number of bubbles increases BECAUSE THERE ARE MORE COLLISIONS BETWEEN THE YEAST AND THE SUGAR. Number of bubbles produce d by yeast in 1 min Temperature ⁰c At higher temperature the number of bubbles goes down BECAUSE THE HIGH TEMPERATURE STARTS TO KILL THE YEAST

The number of bubbles goes down steadily A THERE IS LESS LIGHT ABSORBED BY THE POND WEED SO LESS PHOTOSYNTHESIS TAKS PLACE Number of bubbles produce by pond weed in 1 min Distance of lamp from tube cm

Explain what these graphs show Temperature of water ⁰c Number of bubbles produced by pond weed in 1 min Time min Light Intensity lux