Scientific method y based on empirical data (product of observation) y operation definition: when conducting an experiment you have to define when you are doing so someone who wants to replicate the experiment they know what s going on y you can never prove a theory. Survey method: a set of written questions that is used to determine peoples beliefs, attitudes and behaviours. The advantages of this is efficient and cheap (aka paper pen, online) The disadvantages of this are that the questions can be misunderstood/misinterpreted. When conducting a survey it is impossible to survey everybody so to gather research a sample of the place. Smoking teenagers, surveying toronto may be biased due to circumstance. In order to generalize from the sample to the population, the sample must be representative of the population. To avoid this issue, random sampling is used. Random sampling: each person in the population has an equal chance to be chosen for the sample.