# Resolved: Can someone explain it to me please? sorry, this question is about the previous quiz.

the question is:

which of the following classifies as an experiment but not a trial?

1- flipping a coin 20 times and recording different outcomes

2- flipping a coin 20 times and recording the outcome of the last flap

3-flipping a coin once and recording the outcome

4- flipping a coin 20 times without recording any of the outcomes

the correct answer is 1.

I have a good background in summary and inferential statistics

but something is missing it is not clear to me. I can't get the point, 1,2,3 and 4 all are experiments and all have trials and events(outcomes)

Hey Feras,

Thank you for reaching out!

For this quiz, you would need to follow the definitions of a "trial" and an "experiment" used in the lecture. According to the lecture, "after doing one flip and recording the outcome, we complete a **trial**. By competing multiple of these trials, we end up conducting an **experiment**." Therefore:

- "Flipping a coin 20 times and recording the outcome of the last flip" is considered a single trial (the last flip you've recorded)

- "Flipping a coin once and recording the outcome" is again considered a single trial as you've flipped the coin and then recorded the outcome.

- "Flipping a coin 20 times without recording any of the outcomes." is considered neither a trial, nor an experiment, as you don't have a record of any of the flips.

- "Flipping a coin 20 times and recording the 20 different outcomes" - this is considered an experiment as it is comprised of 20 trials.

I hope this clarifies any confusion. I agree with you that the question can be formulated clearer. I remain available if you have any further questions.

Kind regards,

365 Hristina

Hey Hristina Hristova

first of all, thank you very much for your detailed answer, it is very clear now,

Except for the part:

"Flipping a coin once and recording the outcome" is again considered a single trial as you've flipped the coin and then recorded the outcome.

Do you mean replicates or repeating trials is a main component of an experiment?

thanks again

Hey Feras,

Yes, that's correct. A set of trials composes an experiment. Of course, you can say that your experiment consists of a single flip but that would hardly lead to meaningful results :)

Kind regards,

365 Hristina