Evidence is anything that helps solidify our stance on something or that helps us solve a crime/problem.
There are various types of evidence though and all of these are taken into consideration when it comes to solving anything and it is because of various types of evidence that we are able to reach a conclusion after adding different pieces of the “puzzle’ together. No matter how many types of evidence you come across, these are all essential to help understand a crime scene. For example, in case of a robbery, you’d need to look at evidence as to how it took place; consider why it may have taken place; who was involved in the process; what prompted the robbers to rob a house, bank or whatever the crime scene may be and a lot more. Without looking at all of these aspects it would be difficult for you to reach a conclusion or make any sort of judgment over the matter and most of what you say would be hearsay without evidence to back up your stance. Similarly, as a researcher you’d need to look into various types of evidence to prove why you are right and why people should believe you.
The first of the four primary types of evidence is statistical evidence.
This would help prove a point by stating that a certain percentage of the population is suffering from, say, a disease due to lack of protection against that disease or because preventative measures weren’t taken. This is just one of the many reasons due to which people rely on statistical evidence.
Then, there is testimonial evidence. As the name of such evidence suggests, this type of evidence is dependent upon the testimony of people.
Testimonial evidence is used by salespersons and commercials to help prove that a product or service is actually effective. Lawyers, too, go for testimonial evidence- when the “witness’ is made to stand at a podium and describe details of a crime scene from his own perspective, he is actually providing the jury with testimonial evidence.
The third of the main types of evidence is anecdotal evidence which is dependent upon how a person views the world. It is laden with judgment and generalizations because of which it is not exactly the most reliable type of evidence out there. If statistical evidence is added in, this may help prove a point more and your stance would be more credible as well.
The fourth type of evidence is used when conducting researches on topics that have never really been looked into before.
Since there may not be enough material to be able to carry out research, the only thing you can do is resort to analogy to help reach a certain conclusion. Perhaps the situation may be compared to one that has been extensively researched upon and would help you reach a conclusion. However, you would literally have to start from scratch to be able to look into a topic and explain your point to others.