I need feedback on MCQ test in IJSO style

[AlexJicu08]

Homework Statement

I have designed an MCQ test in IJSO style. IJSO (International Junior Science Olympiad) is a competition for children 15 or younger in physics, chemistry and biology. I want some opinions on how enjoyable and difficult the problems are. The IJSO consists of an MCQ test, a theory test and an experimental test. I will post a theory test i made in the IJSO style, but i'm still working on a document with the solutions.

Relevant Equations

I don't know what relevant equations i can add in this field

Solutions are also attached as a file

 

[kuruman]

It looks like the problems in the pdf files you posted are not the ones you designed. Am I right?

 

[Mark44]

@AlexJicu08 I count 30 problems in your PDF. With that many problems it's unlikely that anyone will take the time to read them all, let alone provide feedback on them. You'll probably get a better response if you post one or two of them at a time per thread start.

 

[Vanadium 50]

And it would be helpful to post them here direct;y rather than making your readers download a PDF file. Note that equations are supported via LaTeX.

 

[AlexJicu08]

It looks like the problems in the pdf files you posted are not the ones you designed. Am I right?

They are the ones I designed

 

[AlexJicu08]

@AlexJicu08 I count 30 problems in your PDF. With that many problems it's unlikely that anyone will take the time to read them all, let alone provide feedback on them. You'll probably get a better response if you post one or two of them at a time per thread start.

I made the entire test just like the mcq in the ijso, I tried to make it in the ijso style.

 

[AlexJicu08]

And it would be helpful to post them here direct;y rather than making your readers download a PDF file. Note that equations are supported via LaTeX.

Thanks for the advice. I will keep that in mind.

 

[Mark44]

I made the entire test just like the mcq in the ijso, I tried to make it in the ijso style.

But none of that is relevant here, where you're trying to get feedback on these problems.

 

[AlexJicu08]

But none of that is relevant here, where you're trying to get feedback on these problems.

Yeah, but everyone can look even just at first problem, I don't really mind, I just want some feedback. If there is anyone interested, even one person who wants to work the test, I posted it so it is available here. If this kind of posts are not appropriate for this website, you can tell and I will search for communities which specifically about problem making.

 

[kuruman]

Wherever you choose to post, I think you should post your solutions not the answers. I also think that you recheck whether each answer is reasonable. For example, with Q9, a 1-kg ball is sliding down the circular arc and you are asking for the normal force at the bottom of the arc. Your purported answer is 4.5 N. Do you see why this answer cannot possibly be correct?

If you want to design problems for others, before you start worrying whether they are enjoyable, hard or easy, you should develop mechanisms and methods for verifying that your work and answers are correct. Just because an answer pops out of your calculator or spreadsheet doesn't make it correct. Think of ways to prove it incorrect. Verify the validity of your starting equations and recheck your algebra step by step. Justify every step. Try a different approach and see if you get the same answer. These are a few things to look for. Writing problems for others is more complicated than it looks.

 

[jbriggs444]

Yeah, but everyone can look even just at first problem, I don't really mind, I just want some feedback. If there is anyone interested, even one person who wants to work the test, I posted it so it is available here. If this kind of posts are not appropriate for this website, you can tell and I will search for communities which specifically about problem making.

When you solicit free help, the onus is on you to make things easy for the people providing assistance.

When one solicits help in a discussion forum, each thread is best when focused on a single, well specified, short, bounded request..

When taken to task, the proper response is "I was wrong and I apologize". Not "please I just want a little help".

 

[AlexJicu08]

Wherever you choose to post, I think you should post your solutions not the answers. I also think that you recheck whether each answer is reasonable. For example, with Q9, a 1-kg ball is sliding down the circular arc and you are asking for the normal force at the bottom of the arc. Your purported answer is 4.5 N. Do you see why this answer cannot possibly be correct?

If you want to design problems for others, before you start worrying whether they are enjoyable, hard or easy, you should develop mechanisms and methods for verifying that your work and answers are correct. Just because an answer pops out of your calculator or spreadsheet doesn't make it correct. Think of ways to prove it incorrect. Verify the validity of your starting equations and recheck your algebra step by step. Justify every step. Try a different approach and see if you get the same answer. These are a few things to look for. Writing problems for others is more complicated than it looks.

Ok. I will review them and, I will work on a document with the solutions. The question at Q9 is wrong and it is actually supposed to ask for the normal at the top of the ramp. Thanks for pointing this out.

 

[AlexJicu08]

Ok. I will review them and, I will work on a document with the solutions. The question at Q9 is wrong and it is actually supposed to ask for the normal at the top of the ramp. Thanks for pointing this out.

I just read the problem and it says when it is at a 90 degree angle.

 

[kuruman]

I just read the problem and it says when it is at a 90 degree angle.

Yes, sorry I misread the problem. I get 4.9 N which is close to 4.5 N. I think that you should clarify that the normal force is to be calculated at the position shown in the figure.

 

[AlexJicu08]

Yes, sorry I misread the problem. I get 4.9 N which is close to 4.5 N. I think that you should clarify that the normal force is to be calculated at the position shown in the figure.

Ok. I will specify it. Can you briefly explain how you got 4.9N?

 

[erobz]

Ok. I will specify it. Can you briefly explain how you got 4.9N?

Conservation of energy gives $v^2 = v_o^2 - 2gh$.

The normal force is given by $N = m \frac{v^2}{R} = m \frac{ v_o^2 - 2gh }{h} \approx 4.9 \rm{N}$

 

[nasu]

@AlexJicu08 You get 4.5N by taking g=10 m/s², I suppose. But have you mentioned that g can be rounded to this value? I don't see it.

 

[AlexJicu08]

@AlexJicu08 You get 4.5N by taking g=10 m/s², I suppose.. But have you mentioned that g can be rounded to this value? I don't see it.

I didn't. In my country, at Olympiads, there are some constant we just use with a certain value (for example g=10m/s^2) and I just assumed it's like that everywhere, so I didn't think I needed to mention this

 

[AlexJicu08]

@AlexJicu08 You get 4.5N by taking g=10 m/s², I suppose. But have you mentioned that g can be rounded to this value? I don't see it.

I didn't. In my country, at Olympiads, there are some constant we just use with a certain value (for example g=10m/s^2) and I just assumed it's like that everywhere, so I didn't think I needed to mention this

I will make a page with a table or constante at the beginning of the document, thanks for pointing this out.

 

[nasu]

Can you show some document supporting this statement? For your country.

 

[kuruman]

I also see a problem with significant figures. The input numbers must all have the same number of significant figures and so should the answer options. Question 4 is a good example of hat I'm talking about. The input numbers are given to anything from 1 to 4 sig figs and the options are given in 2 to 4 sig figs. That 84.99% particularly stands out. See this Wikipedia article for the rules on significant figures.

That said, I would encourage you to design problems so that the input parameters and the answers are in symbolic instead of numerical form. For example,
Q.9
A small block of mass $m$ starts at the bottom of a circular frictionless ramp of radius $R$ with initial velocity $v_0$. What is the magnitude of the normal force on the ramp when the ball swings to the top by an angle of 90°?

1. Zero.
2. $\dfrac{mv_0^2}{R}.$
3. $\dfrac{m(v_0^2-2gR)}{R}.$
4. $\dfrac{m(v_0^2-gR)}{R}.$

The advantages of doing it this way are:

• Students spend zero time pushing buttons on their calculators and more time on what counts, thnking.
• Students learn the good habit of solving problems by getting a symbolic answer first and then, if they have to, substitute numbers at the very end.
• Students don't have to worry abut units and conversions that are of minor importance.
• Possible mismatches of significant figures and roundoff errors are avoided.
• As the problem author, you don't have to worry about specific values of constants, e.g. whether $g$ should be 10 m/s² or 9.806 m/s².

 

[AlexJicu08]

I also see a problem with significant figures. The input numbers must all have the same number of significant figures and so should the answer options. Question 4 is a good example of hat I'm talking about. The input numbers are given to anything from 1 to 4 sig figs and the options are given in 2 to 4 sig figs. That 84.99% particularly stands out. See this Wikipedia article for the rules on significant figures.

That said, I would encourage you to design problems so that the input parameters and the answers are in symbolic instead of numerical form. For example,
Q.9
A small block of mass $m$ starts at the bottom of a circular frictionless ramp of radius $R$ with initial velocity $v_0$. What is the magnitude of the normal force on the ramp when the ball swings to the top by an angle of 90°?

1. Zero.
2. $\dfrac{mv_0^2}{R}.$
3. $\dfrac{m(v_0^2-2gR)}{R}.$
4. $\dfrac{m(v_0^2-gR)}{R}.$

The advantages of doing it this way are:

• Students spend zero time pushing buttons on their calculators and more time on what counts, thnking.
• Students learn the good habit of solving problems by getting a symbolic answer first and then, if they have to, substitute numbers at the very end.
• Students don't have to worry abut units and conversions that are of minor importance.
• Possible mismatches of significant figures and roundoff errors are avoided.
• As the problem author, you don't have to worry about specific values of constants, e.g. whether $g$ should be 10 m/s² or 9.806 m/s².

Thanks! I will use this from now on.

 

[AlexJicu08]

The precipitate formed at Q11 is yellow, not white. I just noticed it.

 

[AlexJicu08]

Can you show some document supporting this statement? For your country.

There is no document. We just learn them as they are and, if the problem does not give another value (for example there are problems that give g=9.8m/s^2), we use the one we learned.

 

[nasu]

What is "them"? What do you learn as they are? Isn't the value of g given as 9.8 or
9.81 m/s ² in the physics textbooks in your country?

 

[AlexJicu08]

What is "them"? What do you learn as they are? Isn't the value of g given as 9.8 or
9.81 m/s ² in the physics textbooks in your country?

Yeah, but we consider it 10 Because it is more conevenient in calculations. There are other constants like the atmospheric pressure, speed of sound, speed of light and refractive index of light

 

[nasu]

For a competition, you consider it whatever is given in the competition paper. It is not the same as when you do work in class or you practice at home.