 Challenging the common characterization of explanations as explaining data, Bogen and Woodward advanced the claim that scientific explanations are targeted at phenomena. Instead of defining what phenomena are, they give examples: “weak neutral currents, the decay of the proton, and chunking and recency effects in human memory” (1988: 306). From these examples, it is clear that Bogen and Woodward understand phenomena to be repeatable processes that can be observationally or experimentally detected in multiple ways. On this characterization, cell activities such as protein synthesis or cell division count as cellular phenomena. Although phenomena are often construed as the starting point of research, Craver and Darden (2013: Chapter 4) identify some of the experimental tasks involved in characterizing phenomena such as identifying precipitating conditions, manifestations, inhibiting conditions, modulating conditions, and nonstandard conditions that alter the manifestation of the phenomenon. They also emphasize the role of multiple experimental techniques in specifying features of phenomena. A good deal of research in cell biology is devoted to determining conditions under which cell phenomena such as programmed cell death are initiated or inhibited and cell biologists have been inventive in developing experimental techniques needed to produce these phenomena. Bechtel (forthcoming) points out that phenomena that are the target of explanation range from highly specific (protein synthesis in liver cells under low oxygen conditions) to much more general (protein synthesis generically). Individual research projects often address highly specific phenomena whereas textbooks or review articles discuss more general phenomena.