## General developer forum

### Using students answers in question formula later

Using students answers in question formula later

I'm pretty new to moodle and I'm wondering if it is possible to set up quizzes in such a way that a students previous answer can be used in the next question.

Here is an example of what I want to do

Question 1: What is the value of the voltage used

Question 2: What is the measurered current in the circuit

Question 3:  What is the circuit resistance.

The answer of question 3 is the first answer/ second answer regardless of the values give in 1 or 2

Is this possible

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Re: Using students answers in question formula later

I don't think this kind of question is possible with standard questions.

It is quite possible with the 3rd party formulas question type plugin.

The question would have only 1 part with 3 coordinates.

The part's text would be something like:

Question 1: What is the value of the voltage used {_0}
Question 2: What is the measured current in the circuit {_1}
Question 3:  What is the circuit resistance. {_2}

And the grading criteria would be _0/_1 == _2 or maybe better _0/_1 - _2 < 0.01 to allow for some tolerance.

The part answer can be any list of 3 values that satisfy the equation like [24, 2, 12] it wil not be used in calculations but would be displayed if you check "Right answer" in quiz review options so I suggest not to check that option for this kind of quiz.

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Re: Using students answers in question formula later

Thank for the answer, this looks like what I need but I will have to find out who has admin right in order to get it installed. Thanks

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Re: Using students answers in question formula later

These are basic numerical type questions, and why do you want to use previous answers?

It any part is incorrect then the final amswer is wrong.

I assume you want something using the formula

Calculate R using the formula $$R= \frac{v1-v2}{I}$$  IE dropping resistor.

If it's something else a fuller explanation please.

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Re: Using students answers in question formula later

Answer 3 is only dependant on answer 1 and 2. I would hope to have limits set for the answers 1 and 2 which would be measured values. Answer 3 is an calculated value using the the previous 2 answers.

The circuit is a simple simple resistor circuit with a varied voltage supplied to it. We measure Voltage and current and calculated resistance and check it to the colour code of the resistor. Proving ohms law.

I hope I'm explaining it ok.

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Re: Using students answers in question formula later

I do that as a prac session.  You want to calculate Vs - Vl where Vs is a variable, then assuming as in the attached calculate R.

Would you consider letting your students build a virtual using  the Phet site and handing that in as an assignment?

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Re: Using students answers in question formula later

John

The Phet site looks good, I must look into it more but I would to keep the practical aspect of the  lab. I'm just looking In to trying to make the lab run smoothly and not have the last student you check on be stuck at the first step and the lab is half over.

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Re: Using students answers in question formula later

What version of Moodle are you using?

The Lesson mod might be the way.  I will write some question for you in the morning, when I know version.

John

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Re: Using students answers in question formula later

I'm not sure of the version? But I'lltry to find out. I don't think that I'll be able to add plugins easily. Administrator wants me to see if the existing system will do but I can't blame him. If every user want new things added then things could get messy quickly.

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Re: Using students answers in question formula later

we are using moodle 2.2 at the  moment. Thanks for the offer of help

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Re: Using students answers in question formula later

The easiest way for me to do it is to give you a copy of my electronics course, you can then restore and see the way I did/do it.  The but is the backup is in Moodle 2.4 format. It wont restore properly on earlier versions.

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Re: Using students answers in question formula later

Thanks John

That's very generous of you, i have never backed upped or restored a course, I'll give that a go on Monday and see how I get on.

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