This is an interesting and important question. I’ve never been able to separate assessment from treatment or from a psychologist’s everyday work. First, I think it’s fair to say that assessment is really a process of inquiry. Inquiring into a person’s nature, the nature of a problem and solution, the meaning of an event, behaviour, thought, or feeling and what to do about it, especially if it’s distressing or problematic, and so on. This means that all throughout a psychologist’s work they are making judgments and decisions based on some level of inquiry or assessment. Clients come with their own assessments of who they are, what’s going on, and what might help, and psychologists walk alongside clients to further hone those assessments. Thus, assessment is inextricable from treatment. The question should be less about whether or not a psychologist is assessing and more about how well prepared a psychologist is to produce helpful and minimally biased science-informed assessments. At base, humans are always assessing themselves and their environments (e.g., Why do I feel so bad? What can I do about it?) and psychological science has done so much to make those assessments more helpful and more accurate.
Of course, I can understand a clinician contending that learning formal assessment is different than the assessments psychologists do every day, but the skill set is deeply overlapping. Formal assessment more formally teaches a clinician the ingredients of sound (and unsound assessment), and ought to teach clinicians about the various biases that interrupt good assessment. If we take such skills for granted, they are unlikely to be explicitly or meaningfully learned. If we carve out an intentional requirement for them, we can be more assured that clients are seeing psychologists who are less biased and more competent in their assessments, and thus necessarily more competent in their treatment as well.
Another important component here is pragmatic. The general public expects psychologists to be able to assess and diagnose, and the public has a need for these professional services as well. Moreover, the professional standard across Canada and more globally is that psychologists are competent in assessment and diagnosis. This is because, in the end, formal assessment skills distinguish psychologists from other allied professionals. Thus, Alberta’s Criteria ought to reflect these standards and place our psychologists alongside what is expected locally and globally.