Classical" means traditional. It refers to something rooted in tradition, often tied to historical or long-established practices. For example, "classical art" refers to the traditional styles of ancient Greece and Rome, or "classical education" refers to a time-honored approach to learning. So, if you want to convey that a method is traditional, "this method is classical" is the right choice. "Classic" does not specifically mean traditional. It refers to something timeless, exemplary, or quintessential—something that stands out as a model of its kind. While a "classic" thing might also be old or enduring, its focus is more on quality or recognition than on being tied to tradition (e.g., "a classic car" might be a well-known model from the 1960s, not necessarily "traditional" in design).