A viable academic claim is:
contestable: It must be arguable, and perhaps not in a simple pro-con way. There must be more than one reasonable way to look at it, with possible counter-evidence and counter-logic that must be considered.
specific: It must be grounded in concrete examples and apply discretely to certain situations or under certain circumstances. These are signaled by qualifications, hedges, concessions, and limiters. While these limiters may make the claim sound “weaker,” they in fact make it more sustainable.
substantive: It must matter to someone, somewhere. For academics, this is often signaled with reference to the gap in scholarship it aims to address. For many fields, some levels of importance may be implied or assumed, but not usually in full. E.g., cancer studies don’t have to explain why curing cancer is a good idea, but they do have to signal why this particular study is still needed, what it adds to the field.
These qualities may appear differently in different kinds of claims (the first two of which are the most common for historians):
Claims of discovery are those that uncover previously unknown or under-appreciated sources or phenomenon, analyzing, explaining, and interpreting them in light of some specific question. This is usually called a “claim of fact,” but since I take “facts” represent non-contestable consensus information, I don’t use that term here. For historians, discoveries are always still interpreted.
Claims of cause and effect may uncover new sources, but they also re-examine known ones to challenge or refine existing explanations of cause and effect.
Claims of definition may coin a new term or concept, or they may take a given concept and refine its use, usually for a specific field or discipline, by applying it to an examination of sources.
Claims of value argue for the privileged usefulness of a particular set of subjective values, as distinguished from others, and especially within a given set of circumstances. This is often coupled with other types of claims, especially when multiple viable frameworks of value and interpretation might be applied.
Claims of policy lobby for a particular set of actions to be taken (e.g., by government officials, by other scholars, by the general public, etc.), usually by applying a specific set of criteria to be applied to a given situation.
Sources: Wayne Booth, Gregory Colomb, and Joseph Williams, The Craft of Research, 3rd ed. (University of Chicago Press, 2008). Nancy Wood and James Miller, Perspectives on Argument, 8th ed. (Pearson, 2015).