People are very good at filling in missing information.
Computers are not.
If a person hears:
they may automatically look around, identify the Jordan on their team, decide which foot to use, avoid the defender, and choose an appropriate amount of force.
Those details were not written in the sentence.
A person used context and experience to fill them in.
A computer program cannot safely depend on that kind of unstated assumption.
Programs follow the instructions that have actually been defined.
Imagine these soccer instructions:
A soccer player can probably imagine a reasonable sequence.
A literal system immediately exposes unanswered questions.
Where is the ball?
What if another player currently has it?
Which Jordan?
How does the program know when the pass reaches Jordan?
Who shoots?
What does “shoot” mean in the current situation?
The problem is not that the goal is impossible.
The problem is that the instructions rely on information a human reader is supplying automatically.
Programming requires you to become aware of those hidden assumptions.
A program is made of instructions that a computer can execute.
Those instructions may:
For now, focus on one simple idea:
An instruction needs to be specific enough that the program can determine what action comes next.
Suppose you tell another person:
They might ask:
A person can ask for clarification.
A program only has the instructions and data it has been given.
A better requirement might say:
Now the intended ordering rule is much clearer.
Precision reduces the number of assumptions hidden inside the instruction.
Imagine that the coach's goal is:
The program does not automatically know which information matters to that goal.
The software needs instructions that operate on represented information such as:
That connection reaches back to abstraction and modeling.
Before a program can follow useful instructions, the system must represent the information those instructions depend on.
Consider:
The second instruction depends on the result of the first.
If the program has not identified a player, “that player's name” has no clear target.
Programs frequently build later actions from earlier results.
That makes order important.
The same instructions in a different sequence can produce a different result or may not make sense at all.
Compare:
with:
The second version is easier to analyze because each step has a narrower job.
That does not mean every program should be written as a huge list of tiny instructions.
It means complex behavior becomes easier to understand when you can identify the meaningful actions and the order in which they occur.
When a program produces the wrong result, it is tempting to say:
A more useful question is:
The result may reveal:
This is why debugging focuses on evidence about actual execution.
A computer is powerful because it can carry out defined instructions consistently and quickly.
That power depends on the instructions being clear enough to execute.
When a program behaves differently from what you intended, start with the instructions and the evidence.
The computer cannot rely on “what you meant.”
It can only work with what the program actually represents and tells it to do.