even though valid and reliable are both very similar, they are also somewhat different. They do however rely upon each other. Valid is that stating that something is legally or officially accepted, where Reliable is simply stating that you can trust what you are using. Validity needs to rely on things, which is why they both are so hard to tell apart. For example, just because a Lab result is valid, it does however still need to rely on other things more often then not in order to make it reliable.
