A CLAD fundamental Q

[menghuihantang]

See the attached pic. A lot of people agreed that correct answer is B.

I am so confused. How is it possible B is correct?? I think is C.

Whoever thinks B is the one, can you explain a little to me. Thanks.

[LAVA 1.0 Content]

QUOTE (menghuihantang @ Apr 9 2009, 08:39 PM)

See the attached pic. A lot of people agreed that correct answer is B.

I am so confused. How is it possible B is correct?? I think is C.

Whoever thinks B is the one, can you explain a little to me. Thanks.

I'm not sure who a lot of people are, but C is correct.

[Francois Normandin]

QUOTE (LV_FPGA_SE @ Apr 9 2009, 10:46 PM)

I'm not sure who a lot of people are, but C is correct.

It would be C only after four iterations. It's B in the general case where you get to stop the loop before the fourth iteration.

After four iterations, running average is the same as average of the last four measurements.

[LAVA 1.0 Content]

QUOTE (normandinf @ Apr 9 2009, 09:06 PM)

It would be C only after four iterations. It's B in the general case where you get to stop the loop before the fourth iteration.

After four iterations, running average is the same as average of the last four measurements.

B states that it is the average of ALL measurements, which is incorrect, since it will only be the average of the last four measurements.

An average of all measurements is a weighted running average which is different than this example.

During the first three iterations of the loop it will be a weighted average of the initial measurement and the next i+1 measurements.

[Justin Goeres]

QUOTE (normandinf @ Apr 9 2009, 07:06 PM)

It would be C only after four iterations. It's B in the general case where you get to stop the loop before the fourth iteration.

After four iterations, running average is the same as average of the last four measurements.

Actually, if you stopped the loop before the 4th iteration the result wouldn't be the running average. It would be a weird weighted average of the first measurement (the one outside the loop) with the measurements from each time the loop executed before you stopped it.

That having been said, if I were editing the CLAD I'd rephrase choice B as "The average of all measurements taken since the loop started running will be displayed." That's a clearer description of what it's trying to say.

EDIT: Doh! Christian posted over me while I was typing!

[lightworker]

Looks like a poor question to me with both B and C as possible answers depending on how you interpret the question. Answer B mentions running average, which is true, but doesn't mention the number of values to average over. C mentions the number of values to average over (4) but not the fact that it is a running average. Unfortunately you sometimes get ambiguous questions like this - c'est la vie.

[shoneill]

QUOTE (lightworker @ Apr 12 2009, 10:43 PM)

Looks like a poor question to me with both B and C as possible answers depending on how you interpret the question. Answer B mentions running average, which is true, but doesn't mention the number of values to average over. C mentions the number of values to average over (4) but not the fact that it is a running average. Unfortunately you sometimes get ambiguous questions like this - c'est la vie.

That, in itself, is typical of so many CLAD questions.

Others just SEEM to have multiple answers until thought about enough.

Shane.

[crossrulz]

Agreed that this is poorly written. But I think what they are looking for is the result after the loop is finished (final output). And also keep in mind that they want the "best possible answer". Well, then you are getting subjective based on your point of view on what they are asking.

[shoneill]

QUOTE (crossrulz @ Apr 13 2009, 02:22 PM)

Agreed that this is poorly written. But I think what they are looking for is the result after the loop is finished (final output). And also keep in mind that they want the "best possible answer". Well, then you are getting subjective based on your point of view on what they are asking.

Well a totally different question is what is the "output" of the loop? I would normally tend towards the value in the shift register, but the indicator is clearly the object in question here.

I mean, the Indicator is not actually an output of the loop at all.... The only actual output would be the last single measurement contained within the shift register...

Shane.

[Grampa_of_Oliva_n_Eden]

QUOTE (shoneill @ Apr 13 2009, 08:45 AM)

Well a totally different question is what is the "output" of the loop? I would normally tend towards the value in the shift register, but the indicator is clearly the object in question here.

I mean, the Indicator is not actually an output of the loop at all.... The only actual output would be the last single measurement contained within the shift register...

Shane.

So the correct answer is D, none of the above.

Ben

[shoneill]

QUOTE (neBulus @ Apr 13 2009, 03:40 PM)

So the correct answer is D, none of the above.

Ben

But it's not, I'm pretty sure it's C, thus adding to the confusion.

So many interpretations....

I think a linguistics degree should be compulsory for the CLAD so that you can understand the questions.

Even worse, the question asks what the "output" will be but A to C are phrased "will be displayed". Which is it?

Shane.

[Francois Normandin]

QUOTE (neBulus @ Apr 13 2009, 09:40 AM)

So the correct answer is D, none of the above.

:thumbup:

[shoneill]

Norm and Ben,

Are you guys serious that this might be the answer? That would surprise me more than a little.

The CLAD Questions need a major overhaul.

The amazing thing about most of the Qs is the more I think about them, the less sure I become of the answer. I finished my CLAD exam in half an hour and I think if I had taken longer, my score would have been lower....

Shane.

[Francois Normandin]

QUOTE (shoneill @ Apr 13 2009, 11:14 AM)

Norm and Ben,

Are you guys serious that this might be the answer? That would surprise me more than a little.

The CLAD Questions need a major overhaul.

The amazing thing about most of the Qs is the more I think about them, the less sure I become of the answer. I finished my CLAD exam in half an hour and I think if I had taken longer, my score would have been lower....

Shane.

I'm half joking... because I'm not sure what it should be anymore! I'm in total agreement with you regarding the needed overhaul. Questions should not try to trick you at this level since it's an entry exam. It should try to show that you mastered the basics of LabVIEW, not that you're good in philosophy!

When I took my exam, there was a question about a chronometer-type VI, for which obviously the output was counting down. But all four answers were beginning with something like: "Output counting up, and...", so I chose with respect to what came after the first comma. I might have gotten it right (I don't know !?!) but it proved me that all I had heard so far about the CLAD exam was true.

[crossrulz]

I remember my CLAD exam had some really iffy questions. I barely passed. I'm up for renewal next Wednesday. I think I know my stuff a lot better this time around, but I'm still worried about stupid questions like these.

[crelf]

I think the correct answer is D, but I'll bet a beer that NI's after C.

:!: Remember folks: if you don't like the exam questions, pontificating here is fun, but if you actually want something done about it, contact NI (and post 'em a link back to this thread).

[BenD]

QUOTE (menghuihantang @ Apr 9 2009, 10:39 PM)

See the attached pic. A lot of people agreed that correct answer is B.

I am so confused. How is it possible B is correct?? I think is C.

Whoever thinks B is the one, can you explain a little to me. Thanks.

Sort of off-topic, but does the DAQ assistant give you any kind of timing control, or is this loop gonna run as fast as possible? I've never used LV for DAQ, so I guess it depends on your application (maybe you WANT to acquire that fast) but I've always been taught that running loops without paying attention to timing was bad. And look at all those avoidable wire kinks!!!

[crossrulz]

QUOTE (BenD @ Apr 13 2009, 02:56 PM)

Sort of off-topic, but does the DAQ assistant give you any kind of timing control, or is this loop gonna run as fast as possible? I've never used LV for DAQ, so I guess it depends on your application (maybe you WANT to acquire that fast) but I've always been taught that running loops without paying attention to timing was bad. And look at all those avoidable wire kinks!!!

Yeah, have you ever noticed how NI folks don't have to follow the same style guidelines as us? For the CLD, we have to keep everything easy to read, wires straight, etc. I open up an NI VI and there's wires going everywhere and you can't tell what wire is connected to what terminal. If they expect us to write a certain way, they should be showing it at least in the CLAD exam.

[Grampa_of_Oliva_n_Eden]

QUOTE (crossrulz @ Apr 13 2009, 03:23 PM)

Yeah, have you ever noticed how NI folks don't have to follow the same style guidelines as us? For the CLD, we have to keep everything easy to read, wires straight, etc. I open up an NI VI and there's wires going everywhere and you can't tell what wire is connected to what terminal. If they expect us to write a certain way, they should be showing it at least in the CLAD exam.

:thumbup:

Ben

[jzoller]

Hrm, let's see...

vi.lib, 8.6:

Description 17169 empty of 24142 checked (71.1%)

Tipstrips 136540 empty of 137657 checked (99.2%)

diag depth: 540 items above a value of 6 (2.3% of the total)

# controls: 343 items above a value of 12 (1.5% of the total)

# indicators: 79 items above a value of 12 (0.3% of the total)

diagram width: 11744 items above a value of 1024 (51.0% of the total)

diagram height: 3992 items above a value of 768 (17.3% of the total)

Now, don't get me wrong. While I enjoy poking fun at the CLD expectations vs. reality, I think there is real value in showing the capability to write to a coding standard.

Joe Z.

[crossrulz]

QUOTE (jzoller @ Apr 14 2009, 01:15 PM)

Hrm, let's see...

vi.lib, 8.6:

Description 17169 empty of 24142 checked (71.1%)

Tipstrips 136540 empty of 137657 checked (99.2%)

diag depth: 540 items above a value of 6 (2.3% of the total)

# controls: 343 items above a value of 12 (1.5% of the total)

# indicators: 79 items above a value of 12 (0.3% of the total)

diagram width: 11744 items above a value of 1024 (51.0% of the total)

diagram height: 3992 items above a value of 768 (17.3% of the total)

Now, don't get me wrong. While I enjoy poking fun at the CLD expectations vs. reality, I think there is real value in showing the capability to write to a coding standard.

Joe Z.

My point exactly.

[crelf]

QUOTE (jzoller @ Apr 14 2009, 01:15 PM)

Hrm, let's see... vi.lib, 8.6:

Whilst I enjoy poking fun at others' code as much as the next bloke, I'm not sure that all of those metrics are particularily valuable. I know that my code would look pretty bad on a few of those metrics, and I consider myself a very particular programmer.

Either way, I don't think we should be relying on NI to define what good programming style is, nor should we necessarily be expecting them to adhere to what we think is good programming style. I could be wrong, but I don't think many people look to Miscrosoft as the ultimate when it comes to VB style - most people look to books written by professionals that *use* VB, not those who write VB.

[Grampa_of_Oliva_n_Eden]

QUOTE (crelf @ Apr 14 2009, 02:42 PM)

... most people look to books written by professionals that *use* VB, not those who write VB.

Socrates came to the same conclusion in "Plato's Republic" when discusing "the form".

Ben

[Darren]

Many of the VIs that ship with LabVIEW were written long ago, before too many people thought much about coding standards. We had the AEs go through and scrub all the examples a few years back, so a lot of those should have gotten better. As for vi.lib VIs, those don't typically get edited too much after being written. I do make it a habit to clean up any shipping VI I happen to be editing though (just did one this morning), so given enough years, I may single-handedly clean up vi.lib.

-D

[Grampa_of_Oliva_n_Eden]

QUOTE (Darren @ Apr 14 2009, 03:16 PM)

...so given enough years, I may single-handedly clean up vi.lib.

-D

... and the world will be better for this, that one wire-slinger scorned and covered with wires

Still strove with his last ounce of copper to re-wire the spagetti VIs.

Ben