Describing and Explaining Patterns of Data in Graphs

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

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

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

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

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

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

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