To construct a graph: 1. Always put the independent variable (i.e. the value that changes) on the x-axis (horizontal axis). 2. Decide on a suitable scale for each axis. 3. Label the x-axis and the y-axis and include the correct units. 4. Plot the points accurately. 5. Give the graph a title and date.
3. Processing and analysing
Recording data clearly helps scientists to identify patterns and relationships between variables. An advantage of presenting scientific data in a graph is that it makes any trends easy to spot. A
• The graph in Fig. 1.6 shows a relationship between variables that is directly proportional. As one value increases, the other increases.
• The graph in Fig. 1.7 shows a relationship between variables that is inversely proportional. As one value increases, the other decreases.
Forming a conclusion
When the results of the investigation have been analysed, a scientist can form a conclusion. The data produced during the investigation can be used to show that a hypothesis is or is not supported. Scientists often test several different hypotheses before they arrive at the answer to the question they asked.
8 Elements of Science
B
Number of people who go on holidays Length of shadow (m)