It should always include observations. It will contain data tables marked off in neat, compartments. When appropriate, the percent error should be calculated in this section. If a graph is needed, it should be in this section. If any of the steps given here were to be considered the most important, it would be this one.
Elaboration is needed here.
Observations should be analyzed. Speculations must be made concerning the agreement or disagreement between the final results and the hypotheses. When the results do not agree with the accepted value, possible sources of error should be specified. This is always a required part of the lab report and it does require some thought and maybe some research. Or followup investigations that could be done on different topics by using the data and results of the current experiment as a basis.