Without knowledge of the original pigment's color we cannot be sure if we are observing change, we are lacking information needed to understand the artist's original intent, and it is challenging to specify suitable display conditions and/or treatment options.
Although there have been some studies for identifying the prognostic factors for HCC patients with brain metastasis, it is challenging to specify the appropriate therapeutic strategy considering its rare incidence and poor prognosis.
In the absence of clear indications for using the log-rank or Wilcoxon test for the comparison of survival curves legislators might be challenged to specify unambiguous rules if necessary.
It should be noted that from the literature, E. coli is thought to have a bi-modal distribution around the previous direction (Berg and Brown 1972), the validity of this is hard to confirm as previous data were hand-annotated, and it is challenging to specify the state of the bacterium when diffusion effects are also in place.
The challenge is to specify what role observation plays in measurement, and particularly what sort of connection with observation is necessary and/or sufficient to allow measurement to play an evidential role in the sciences.
A bigger challenge is to specify mutations that endow a new function, such as a lost functionality in a duplicated gene.
The first challenge is to specify whether the object of explanation is a trait universal in the species or variation in a trait (Q1).
This challenge is to specify what that normative consideration is without invoking the language of dignity and without invoking considerations that are either implicitly or explicitly theological, and, thus, are unacceptable given the canons of public reason that are essential for public debate in multicultural and multi-faith societies such as Canada.
An AI researcher in the classical mould could rise to this challenge by attempting to specify what propositions are relevant to what context.
It would be a challenge for philosophy to specify the differences among action forms and the reasoning grounding them in, to single out three prominent practices, technology, organization and management, and economics.
