Direct observation. It is a way for people to observe natural phenomena under natural conditions by looking carefully with their eyes. Be careful when observing, don't let go of any subtle details. At the same time, the observation should be recorded in detail, otherwise it is impossible to get real first-hand materials.
Hands-on experiments. The experimental method is to artificially intervene and control the research object, which is more conducive to giving full play to the initiative of students to reveal hidden natural mysteries than observation.
Field trip. Including investigation, visit and field trip. Before the inspection, the purpose of the inspection and the necessary tools, instruments, medicines, daily necessities, etc. must be made clear. Must be prepared. In the process of inspection, it is necessary to record the time, place, process and inspection results in detail at any time and place, and sometimes bring back necessary specimens and samples to take pictures of more important phenomena. These are very useful first-hand information.
Check the information. Due to the limitation of time, space or objective conditions, it is impossible to observe, experiment and investigate some materials in person, so we have to consult books and periodicals or consult teachers and parents. This indirectly obtained material is called second-hand material. Some problems can't be solved by your knowledge level, ability and conditions. This problem must be solved in your topic selection, so you have to check the information and find out.