How smart is this candidate?

From a CEO who asked to remain anonymous:

We all want to hire smart people. At the same time, asking an interviewer to rate candidates on how smart they are is too vague. Instead, we’ve found it helpful to ask interviewers to rate candidates on these characteristics:

How precise? How clearly did the candidate articulate their thoughts, ideas? Are they rigorous in distinguishing between different aspects of a problem, or categories that can help define an issue more precisely?

How curious? Did the candidate ask good questions, with good follow up questions? When they think about an issue, are they excited by asking the right questions?

How entrepreneurial? Is the candidate excited to try or test new things? Do they think big? Are they ambitious? Are they self-motivated?

How engaging? How excited was I by the conversation with them? How much did I learn which was new and interesting? What’s my enthusiasm level for spending another hour with them?

Notes:
(1) I’ve found that a good way to assess “how precise” and “how engaging” is to send the candidate a follow up question by email after the interview. You can learn a lot from their replies as the conversation continues in writing. Cf. What to look for when hiring someone to work remotely.
(2) Cf. “For every job the No. 1 thing we look for is general cognitive ability, and it’s not I.Q. It’s learning ability.” in The 3 things Google looks for when hiring.
(3) See also 5 testable qualities that determine a candidate’s potential.