Interview Topic Presentation for a Computer Science job posting

[JoeO]

I am a coordinator at a 2 year college in the US.  I have to write a topic for candidates to present to the interview team.  The candidates will be applying for the position of Assistant Professor of Computer Science.  I have formulated the presentation topic and it is written below.  Could you please give me your opinion as to whether the question is correct and makes sense.  Please be truthful.  If I have made a mistake, let me know.  You don't have to worry about hurting my feelings. 

Thanks for taking the time to read and respond.

"Prepare a 20 minute presentation on the topic of Karnaugh Mapping for 4 literals.  Assume your class has prior knowledge of basic logic gates and simplification of Boolean expressions using Boolean Algebra.  Give examples of the process and outline the common mistakes that students make.  Prepare any handouts you deem necessary (copies can be made by the department secretary in CS206.)  You will have access to a computer with Internet access, a multimedia projection unit and an overhead projector. "

[Galaxyrise]

I find it much more obvious to speak in terms of variables than in terms of literals.  I had to look up how literals relate to Karnaugh Maps. I presume you you mean a 4-variable Karnaugh Map (each row and each column specify two literals) and not a larger Karnaugh Maps where a row or column specifies 4 literals?

This sounds like something you'll have the candidates do over the course of days before the interview?  Where I went to school, Karnaugh Maps were handled by the Engineering department, so the CS profs wouldn't really have experience teaching it; wouldn't know first-hand the sorts of mistakes students make.

[IanB]

I also seem to think Karnaugh maps are an EE topic rather than a CS topic.

Someone from a CS background could no doubt read up on the subject and prepare some teaching material, but as Galaxyrise says they may not have prior experience of teaching it.

[free_electron]

Karnaugh ? You are joking right ? That is useless these days. Beyond 4 variables karnaigh is unworkable. Quine McKlusky is the way to go. But that can't be explained in 20 minutes.

Since they are going to be teaching computer sciense :
Have them explain a basic cpu.
Alu , fetch unit , instruction decoder , ram and rom , input and output.

[jaxbird]

Agree with everyone, that is not topic I would connect with a CS position. If you want to do a classic/fundamental CS subject, instead you could request a 20 min presentation on Dijkstra.

[Stonent]

If you find a cantidate that you don't like, ask him what the purple wire on the ATX power supply does.
Though not a computer science position, we once had someone interview for a job that said "I know everything, I've got my blah-blah-blah certification" so our supervisor said "Ok what does the purple wire on the ATX power supply do?" the guy just closed his briefcase and left.
 

[vk6zgo]

OK,---I'll bite! What does the purple wire do?

[Phaedrus]

+5VSB, the standby rail. Powers the motherboard startup circuitry and real-time clock, and sometimes the USB ports.

It's a dedicated power circuit inside the PSU with its own transformer, after the bridge rectifier and before the PFC stage, that is on as long as the PSU is plugged in and the power switch is on. This is opposed to the other rails in the unit which are activated when the PS_ON (green) wire is pulled low.

[chickenHeadKnob]

Karnaugh ? You are joking right ? That is useless these days. Beyond 4 variables karnaigh is unworkable. Quine McKlusky is the way to go. But that can't be explained in 20 minutes.

I did a 4 year comp sci degree 1979-1982 at a Canadian university. We were taught a digital logic course and it included 5 variable karnaugh maps, and Quine_Mcklusky and more. You can visualize 5 variable as two 4-var tables overlaid, not hard, and I can still do them from decades old memory. Also still remember what a wallace tree is even though I have never used one. The course included labs and building circuits from 74 series. I aced this as I was playing with electronics in my teenaged years autodidact style, - peer cohort students not so much. The  course syllabus didn't seem out of place at the time. Early to mid eighties is when electrical engineering departments in Canada began offering computer engineering course tracks/degrees I might have taken that instead if it had been available.

edit: spelling to re-correct the auto-correct, damm that is annoying.

[EEVblog]

I'm with the others. Karnaugh mapping for CS?
Surely you could use one of dozens of different computer/CPU architecture questions?

[bbarbour]

K-maps are relevant to a CS education.  I teach them in a "digital logic" course that is one of the core courses where students learn the basic building blocks of the CPU.  However, in the overall topic of Computer Science.. they are a footnote on the underside of the night time janitor's shoe.  One I would be willing to bet most, if not all, of my students forget right after their test.  In fact, the only reason I remember them is because I teach it!

You should ask yourself what you hope to learn about the candidate from the presentation.  Personally, I'd be more interested in observing something a bit more directly CS related.. like programming.  Have them explain an algorithm.  Also, various datastructure lectures lend themselves very well to quality visualizations and a variety of approaches to convey the concepts to the students.  A common topic is sorting or searching for example.

[Fsck]

Do you only get 20 minutes total?
Don't know much about hiring but if I were tasked with hiring someone to teach and taking a physicist's approach (ridiculously comprehensive and usually overkill)..

I'd evaluate them at 3 tiers: low level courses, mid level courses and high level courses. Pick a popular/required/foundation course of each tier: ie, newtonian, classical EM, general relativity.
For each tier I'd have them do a very brief lecture (~10-15m) with it's appropriate handouts and have them prepare for you on paper: 1 appropriate homework question, 1 appropriate exam question, both both with their respective solutions and an explanation of the solution suitable for the level of the class.

As with the majority, I don't really view k-maps as very CS-oriented. Programming/algorithms/tedious repetitive math are what scream "fundamental CS" to me.

[John Coloccia]

Karnaugh maps are absolutely relevant to CS, though I agree with Galaxyrise that you probably meant 4 variable.  That said, I couldn't explain a 4 variable Karnaugh map in 20 minutes, never mind any of the subtleties involved....no way, no how.

Without knowing the curriculum, it would be difficult to suggest another topic.  I'd hate to suggest a sorting algorithm because I can't remember the last time I actually implemented a sorting algorithm.  It was probably in college, actually.  One thing that might be reasonable to gloss over in 20 minutes is Semaphores and Mutexes, assuming that the student is already familiar with multi-threaded programming.  It's difficult to imagine a more fundamental CS topic that is simple enough to explain in a few minutes while still being able to talk about some subtleties AND is absolutely and critically relevant in nearly every corner of the software world today.

Is this question intended to test knowledge or teaching ability?

[EEVblog]

For CS I'd probably pick something fairly simple but useful, like Linked Lists. That would show how well they can explain problems visually as well as at a deeper level and pro/cons vs other methods.