In problem solving, the function we assign to some component of a problem determines how we use it in the problem frame. When we assign the wrong function, it can cause problems. For the Duncker candle problem discussed in the text there was a box of tacks, a candle, a hammer and a book of matches. For well defined problems, the heuristic approach provides a guaranteed solution. A heuristic is sometimes also called a 'rule of thumb'.
Algorithms have a probabilistic solution.
Algorithms are precise procedures for calculating a result from specific starting states. So, in an magnitude estimation task, subjects are not given time to calculate the answer to, e.g., a math problem, but must very quickly make a guess. Sorry, not right. The eagle is a very well known bird, and we see its likeness in many public signs and national symbols, so it is very frequent and familiar. Sorry, not right.