Final answer:
Spontaneous, uninstructed use of analogies as a heuristic is quite rare. Heuristics are mental shortcuts used unconsciously to efficiently solve problems, in contrast to the step-by-step procedure of algorithms.
Step-by-step explanation:
The student's question is concerned with which heuristic is spontaneously and rarely used without instruction. The answer to this question is analogies. While people often use various heuristics unconsciously as mental shortcuts to efficiently solve problems, the spontaneous, uninstructed use of analogies as a heuristic tends to be quite rare. An analogy involves recognizing a similarity between two different situations, which can provide insights for problem-solving.
A heuristic is a general problem-solving framework or a 'rule of thumb' whereas an algorithm is a detailed, step-by-step procedure that guarantees a correct answer if followed meticulously. The working backwards heuristic, for example, starts with the end result and works backwards to solve the problem.