Question about the diagnostic example

I plan to take the PE exam this year, and I found a diagnostic example from NCEES.

Attached is the graph, and I have a question about it. We could see the distance between the average of passing and what the person did, but the distance refers to the distance of correct percentage or number of correct answer?

For example, we could measure (by ruler) that the distance (length of orange part) for Mass Balances is about 1.5 times of the distance (length of orange part) for Energy Balances & Thermodynamics, but is the "1.5" refers to the ratio of " number for correct answer of average passing for Mass Balances minus 3" to "number for correct answer of average passing for Energy Balances & Thermodynamics minus 5"?

Or the number of "1.5" refers to the ratio of " percentage for correct answer of average passing for Mass Balances minus 33%" to "percentage for correct answer of average passing for Energy Balances & Thermodynamics minus 50%"?

If someone can help me with this question, and provide me the answer, I will be able to calculate the percentage score for passing the whole exam based on this graph.

Thanks.

seriously, don't worry about the passing score.  Study like you need to get all of them correct.  If you must, just assume 70%.

P-E said:

seriously, don't worry about the passing score.  Study like you need to get all of them correct.  If you must, just assume 70%.

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Thanks for your reply.

I agree with you, but I am interested in solving this problem by mathematics as an engineer, so I want to calculate for an accurate answer.

Chunhui Jiang said:

Thanks for your reply.

I agree with you, but I am interested in solving this problem by mathematics as an engineer, so I want to calculate for an accurate answer.

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Unfortunately, the passing score changes from year to year and by discipline.  They will never tell you. 

P-E said:

Unfortunately, the passing score changes from year to year and by discipline.  They will never tell you. 

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Yes, but my goal is calculating for an accurate data based on this graph even this graph cannot prove other conditions.

Chunhui Jiang said:

Yes, but my goal is calculating for an accurate data based on this graph even this graph cannot prove other conditions.

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You are welcome to interpret the graph as you see fit to make your perceived calculations.  However, based on your first post, the questions you have can only be made using certain assumptions since NCEES controls the true calculation process.  So based on that, your calculations will be at best theoretical.  Seems like an exercise in futility as I'd rather be spending my time more wisely preparing for the exam itself.

I don't think the bars refer to a strict ratio OR absolute value. They are almost artistic.

For example in no case will getting ZERO correct NOT result in you getting a full length bar to the left (even for topics where there is only one problem!). In no case did getting EVERY problem correct result in getting a full length bar to the right. Definitely not scaled, and definitely not absolute offset.

Only thing I can think of is that NCEES doesn't want you to feel good about getting a topic completely correct and hence doesn't publish a result that says YOU CRUSHED fluid transport --"don't worry about it next time!!"

knight1fox3 said:

You are welcome to interpret the graph as you see fit to make your perceived calculations.  However, based on your first post, the questions you have can only be made using certain assumptions since NCEES controls the true calculation process.  So based on that, your calculations will be at best theoretical.  Seems like an exercise in futility as I'd rather be spending my time more wisely preparing for the exam itself.

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Yes, and I think you are right, but I will still try.

JHW 3d said:

I don't think the bars refer to a strict ratio OR absolute value. They are almost artistic.

For example in no case will getting ZERO correct NOT result in you getting a full length bar to the left (even for topics where there is only one problem!). In no case did getting EVERY problem correct result in getting a full length bar to the right. Definitely not scaled, and definitely not absolute offset.

Only thing I can think of is that NCEES doesn't want you to feel good about getting a topic completely correct and hence doesn't publish a result that says YOU CRUSHED fluid transport --"don't worry about it next time!!"

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I think I found something.

We could find out that this examinee did all two questions wrong in term 12, and did all two questions correct in term 18, but the length of the two bars are not the same, which could prove that the graph shows the scale, and the reason is the average is more than 1 question or 50%.

From term1 and term 10, we could find that the graph is based on the percentage, but not number.

The only thing is that for term 8,10,12,20, the real bar may be longer than the bar shown on the graph, because the distance of percentage is too big to show, and has covered all the length to the left, so these data maybe not accurate, but I think other terms shows the scale.

Thanks.

I'm having a hard time thinking of an exercise that is more frivolous or futile.  Take, for example, the simple fact that a 50% in one case results in a bar to the right, and in another, results in a bar to the left.  These graphs don't mean what you think you mean. I don't think they even mean what the NCEES thinks they mean.

Audi driver said:

I'm having a hard time thinking of an exercise that is more frivolous or futile.  Take, for example, the simple fact that a 50% in one case results in a bar to the right, and in another, results in a bar to the left.  These graphs don't mean what you think you mean. I don't think they even mean what the NCEES thinks they mean.

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I think the switch to this format from previous is the biggest DISSERVICE NCEES has ever done for test takers.  

Audi driver said:

I'm having a hard time thinking of an exercise that is more frivolous or futile.  Take, for example, the simple fact that a 50% in one case results in a bar to the right, and in another, results in a bar to the left.  These graphs don't mean what you think you mean. I don't think they even mean what the NCEES thinks they mean.

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The reason is that for some term of the questions, the average collect percentage is less than 50%, but for some term, that is larger than 50%.

snickerd3 said:

I think the switch to this format from previous is the biggest DISSERVICE NCEES has ever done for test takers.  

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I think NCEES really do not want us to know the passing score.

Chunhui Jiang said:

I think NCEES really do not want us to know the passing score.

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Exactly.

Chunhui Jiang said:

The reason is that for some term of the questions, the average collect percentage is less than 50%, but for some term, that is larger than 50%.

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So you think.  You don't know anything for sure, it's all purely guessing.  Thus: futile.

Chunhui Jiang said:

I think NCEES really do not want us to know the passing score.

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that has always been obvious.  I am talking about the format of the diagnostic report in general.  Previously it just identified where the person needed to work harder.  now they provide the bars and it leads to all this unnecessary guesswork calculations on what the minimum needed to pass next time vs trying to actually study and try to try to score higher.

thekzieg PE said:

Exactly.

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But we can calculate for that.

Audi driver said:

So you think.  You don't know anything for sure, it's all purely guessing.  Thus: futile.

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Of course I am sure about the answer of your question.

snickerd3 said:

that has always been obvious.  I am talking about the format of the diagnostic report in general.  Previously it just identified where the person needed to work harder.  now they provide the bars and it leads to all this unnecessary guesswork calculations on what the minimum needed to pass next time vs trying to actually study and try to try to score higher.

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I do not know about others, but for me, I am just curious and want to do a calculation, and I do not think it will have any effect on my study.

Chunhui Jiang said:

Of course I am sure about the answer of your question.

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hahahahahaha I don't even have a question.