A friend who works at a startup was recently explaining that the company’s biggest problem at the moment is its inability to find suitable engineering talent.
As a barometer, one of the "questions" it poses to interviewees is this:
You have a 10V ideal voltage source in parallel with a 5Ω resistor. What is the impedance?
So far, no one has answered correctly. (The answer is provided at the end, in case you want to take a shot at it.)
My friend says, “Engineering students today can't answer basic engineering questions. And we aren't talking about tier 2 or 3 universities, either.”
She tells the story better than me, so here are her words:
This is a well-known problem, one which I have discussed/commiserated with friends from two other firms with the same issue. One is in Massachusetts and the other is in Texas, so clearly this isn’t just a regional thing.
When you look at these people's resumes, all is sunshine and rainbows. When you ask them questions about their accomplished projects, it becomes clear that they have no clue what these so-called projects were really about. They can't answer. And not just undergrads; we rarely interview undergrads. We are talking about folks with MSs and PhDs.
Some are specialized to the point of absurdity, which I suppose makes some sense if you are going to be writing a thesis, but because they lack basic understanding of the underlying physics, they really don't know their specialties all that well, either. Plus, many have difficulty communicating in English.
The bottom line is that the schools are to blame. They should not be graduating people who do not understand the material they were taught.
She went on, including what she considered unrealistic salary expectations, but you get the gist of it. Are you seeing a similar situation out there? Tell us about it in the comments section below.
Spoiler alert: The answer to the question is 0. It's a trick question. The amount of the voltage is irrelevant. The key phrase is "ideal voltage source." The real purpose was to see if they knew what an ideal voltage source was.
I would look lower in the educational food chain. I think that people coming out of 2 year programs probably have more practical knowledge than the average PhD. If you want people to talk about stuff, hire PhD's. If you want people to actually do something, hire someone that can do stuff.
I look at it this way: no matter who you hire, you are probably going to essentially train them yourself, from the ground up, to do what you need done. I would go for the best raw material, and that may not be someone with a PhD. You are just going to pay more for the raw material, and you will probably still have the same amount of training to do.
I don't blame it completely on the schools. I find that you get out of education what you put in to it. Students that are really interested in becoming engineers will apply themselves and do well. People who are in engineering studies because they think engineers make good money probably won't be very good engineers.
Rich, this is distressing news. I agree with ttemple. It is often necessary for companies to train people themselves. You do expect a basic level of understanding, but that can sometimes be lacking. Actually, I am suprised by your friend's findings. I just went through the process of looking at engineering schools. I also have a nephew who is in one. They all seem to have strong co-op programs where the students get great experience. Many of the students actually do know their stuff and the companies often don't really want to let them go.
Now, I remember being asked questions that were irrelevant in interviews. These were done specifically to trip people up. Just like your example. I looked at the question and thought, that seems strange. I had never been asked that before, or used it. So, being on-line, I looked it up. It still didn't make sense. If it was something that was needed for a project, I would study the situation and figure out how to solve it. Of course, it would turn out that there was no answer.
So, I don't know what the answer is. Do you decide there are no good engineers becuase they cannot answer trick questions. Many of the engineers your friend is rejecting may go on to do well at his competitors.
One other thing that does interest me today. Many years ago, I had a high school teacher who stated, from experience, that companies would not hire the bottom 10% of the class or the top 10%. The bottom is obvious, but he had a reason for the top 10%. Companies used to consider these too cerebral. They should become professors at a university. How attitudes have changed.
I remember when I first interviewed with Dallas Semiconductor fresh out of school back in the day, I was told I was hired for two reasons. The first one was that I was the first person after two weeks of interviewing that answered a basic question on their technical test correctly (had to do with a circuit and all the voltage falling across an open) and that I represented myself as being able to work well with others during the interview process. What I learned upon being hired is that I had a lot to learn! I was working in product engineering on nonvolatile RAMs at the time and it was a whole new world to me. Same thing when I moved over to Optek Technology and started out on hall effects. In the semiconductor industry we typically expected a year minimum for someone new to really understand the various facets of their job and to be able to contribute independently.
I think if a person is excited about their field and demonstrates a basic competence with a willingness to learn and an ability to work with others and be a team player - hire 'em!
I have to agree that question is not a good barometer. When I read it my instant answer was 5 Ohms. That is probably what I would have answered if somebody had demanded an immediate answer to the problem. Having seen the question with a bit of leisure, my native caution kicked in. I then realized that it said the resistor was in parallel with the voltage source, WHICH IS NOT A NORMAL, USABLE CONFIGURATION. It is, in fact electrically equivalent to a voltage source that mysteriously uses power for no apparent reason. I then realized that the impedance was zero. Neither the voltage given nor the impedance given had anything to do with anything. I need to say this entire process went through my mind in less than a minute, with no reference to the actual answer (I hadn't even followed the link to the article). In short, my initial gut reaction was wrong, but when I thought about it a moment, I got it right.
My point here is that the fact that nobody answered correctly has more to do with the fact that they were asked a practically irrelevant question with an implied "hurry up and answer" than it has to do with them not knowing their stuff.
Having said that, I am personally frustrated by other more reliable evidence that engineers today don't know their stuff. Unfortunately, finding a reasonably fast way to screen out the ones who really do know it escapes me. Most people can get through a 20 question exam when they have just taken the course work. If somebody comes up with a way to quickly and reliably identify those who "get it", please pass it to the Universities. If they implement that, the quality of their graduates will skyrocket.
I agree, ttemple. I've said for years that the stronger graduates are those who've worked in part time engineering jobs and co-op programs. In the late 1950s, after our national overreaction to Sputnik, universities migrated towards more theoretically-based engineering programs. Courses emphasized theory more and practicality less. That's why co-op programs are so important: As you so accurately point out, it's up to the individual to make the most of what's being taught, and when it comes to that, there's no replacement for real-world experience.
ttemple, I think you dismiss PhDs a bit too swiftly in too general a manner. I would look very differently at a PhD holder who earned it in one continous educational period, from B.S. to PhD, than I would someone who worked in industry for a time with a B.S. then went back to school to earn the PhD.
That second candidate is likely to be much more grounded and useful, and the PhD itself more useful to your company.
" I think you dismiss PhDs a bit too swiftly in too general a manner."
Point taken. I didn't mean to be swift and general in dismissing PhD's. I was really trying to make the point not to be swift and general in dismissing non-PhD's, and even non BS's.
I believe a lot of productive talent is overlooked by indiscriminately filtering candidates by degrees. There are many people who have the raw material to be very good engineers, but they don't have the guidance around them, or the financial resources to seek the "appropriate" education. They might, however, find their way get through a 2 year program at a tech school. I think our current HR structure overlooks these people (by "degree as a litmus test" practices), and does so to the detriment of everyone involved.
If you need a PhD because of the nature of the position, by all means, look for a PhD to fill the position. Most work that needs to be done doesn't need to be done by PhD's, however.
I completely agree with your differentiation between PhD's who only went to school, and those who went back after/during work.
@ttemple : Just be aware that without the BS the odds that they can do the analysis goes way down. I know there are plenty of degreed Engineers that can't do the analysis because they don't care about the math. The flip side of the coin is that they don't teach the analysis in a 2 year program at all! At best they will teach a few basic formulae. So, someone without a BS that can do the analysis either taught themselves or spent a lot of time with a very patient mentor. Neither is likely.
I find a more common problem is finding people who can recognize when analysis needs to be done. I care more that a person has the instincts to know when further analysis is needed than whether or not he can do the actual analysis. I can find someone to do the analysis. It is more dangerous when someone forges ahead on something that needed analysis, and never even recognizes the need.
I have had employees that had no degree at all that had a great sense for this, and I've seen "engineers" who have no sense at all for it.
The point I think is important is that there are a lot of people of all educational levels that don't recognize the need for the analysis. In my experience, technicians will often persist until they come up against something they can't overcome. The problem with that is if they get a workable solution before they hit a brick wall, they will overlook hidden problems.
Those come back to bite their company years later. I know, I have dealt with several such cases.
That is why it is important to have someone on the team who not only can do the analysis, but has a good understanding of what the results mean. Often enough, only one such person is enough, but their contribution is vital. That kind of ability comes with good education (BS or higher), real interest, and good experience.
What alarms me is the number of people who call themselves engineers who are no more able to analyze a problem than a High Schooler. We count on these people to give us safe, reliable products, and they are fundamentally unable to foresee certain kinds of failures. That is why we need to find better ways to make sure the people with BS degrees are able to use what we have tried to teach them, and to value those who can.
@Fred McGalliard, why does it matter if the power supply is off? You were taught in school what an ideal voltage source is, and maybe the point of the question is to see if the applicant remembers that it has 0 ohms impedance, and to see if the applicant remembers how to find the Thevenin equivalent resistance of 0 ohms in parallel with 5 ohms.
As for relevance to the real world, many DC supplies are close approximations of an ideal voltage source. Give the applicant a schematic of a basic unregulated AC-DC supply -- a transformer, a bridge rectifier and a filter capacitor. Put a 5 ohm load on it, leave the supply turned off and ask him what value an ohmmeter will read when he measures across the output terminals. If you want to give him a hint, tell him the resistance of the transformer secondary winding is negligible.
I've found that looking at and questioning a candidate's experience is far more important than knowledge questions. For the freshly minted engineers it falls on school projects and personal hobbies. For the more seasoned engineer it is actual work experience.
Generally, we look for people that can work in teams and can think broadly. We develop hundreds of one-off prototypes and science experiments. So thinking outside the box is important but also thinking inside the box can move you faster down the road.
When we do ask questions like the one presented above it is to get an idea of how someone might approach a problem and less about if they can pick up on key words or to test their knowledge. The problems are far more open ended and may not have any 'correct' answer. HR hates these sorts of questions as well as a manager that is just trying to weed through the candidates.
@scottmorris: I agree. It's much more useful to ask questions that show how the candidate approaches problems than to simply quiz them on knowledge or vocabulary. Knowledge and vocabulary can usually be picked up relatively easily; it only takes a minute or two to explain what an "ideal voltage source" is. Problem-solving approaches, on the other hand, take much longer to learn.
I also try to gauge the candidate's general attitudes. Are they excited about the technical details of the work, or bored by them? Are they curious about the things they see around them, or indifferent? Are they genuine in their interactions with others, or are they obviously trying to ingratiate themselves? When talking about their experience, do they have interesting stories to tell, or do they just rattle off a list of accomplishments?
Ultimately, it's very difficult to know how well a person will perform in a given role based on their performance in an interview. You need to understand that you are getting a very limited view of a person, under conditions that are very different from those of everyday work.
Unfortunately, the only way to really know how a person will perform in a job is to give them the job and wait a year or so -- but obviously you can't actually do that for every candidate!
By the way, a number of people have expressed a negative view of engineering Ph.D.'s. This is a common view; I've seen more than a few job postings that specifically say, "No Ph.D.'s need apply."
It's unfortunate that so many people think this way. There seems to be a certain amount of know-nothing anti-intellectualism to this view ("we know more than those eggheads do," etc.).
On the other hand, it's also true that there is sometimes a big disconnect in engineering between academia and industry. When I read academic engineering journals, I often see articles that seem to have little or no practical value. (On the other hand, there have been many technological and scientific advances that at first appeared to have no practical value).
But the idea that you shouldn't consider a candidate simply because he or she has an advanced degree strikes me as misguided, at best. You should evaluate the individual on the basis of his or her merits.
Dave, Nicely stated. I agree that interest in the job position as well as telling a story about a project you've worked on are good indicators of a person's qualifications. When item I stress to my students is having a strong hands-on with electronic circuits. An engineering, in my opinion, is not only good at analytics but must possess a passion to build and test devices. I look for those quailities in candidates I'm interviewing.
"A passion to build and test devices..." I could not agree more with your comment, mrdon!
One thing is absolutely clear: present day engineering graduates seem to lack a true passion for many things! But you hit the button when saying "a passion to BUILD..." Most recently graduated young engineers that I interview in order to select those who at least promise a minimum actual value as professionals and recommend them to be hired, LACK interest in technical/scientific or engineering subjects and are totally incapable of building anything. On the other side, most colleages from my age (about 57) that have shown to be really good engineers, always have shown a strong interest in technically oriented hobbies, science and specially the capability of building useful devices. They are able to build, fix, repair things, and usually have at least the intention to find what was wrong.
People that throw away appliances at first sign of a problem, and that immediately think about calling a repair shop or technician instead of becoming interested in solving the issue by themselves, usually end up in administrative jobs and never become truly good engineers. Amclaussen.
Amclaussen, I noticed that as well with engineering candidates I've interviewed in the past. The best engineers are the ones who like to build and test devices. The engineering students I've taught I'm always explaining the approach to truly understanding how a circuit or system works is by building or testing them. The passion to build an test is powerful force for engineers!
I think a lot of the frustration is also due to improper expectations of what new graduates are capable of. When I hire new grads, I'm looking for someone who has 'learned how to learn quickly' and who is willing to be developed (not for someone who is an expert in my field yet). Also, I'm looking for credibility and will actually test the claims they make on their resume. If they claim they are well-versed at a particular CAD system, I have them sit down an actually model something. I've found these type of tests quickly show who the star performers are.
I agree with the practical portion of interviews in looking for an engineer. It is amazing how many people that say that they are well versed in CAD can not model a cylinder. It would be understandable if someone that knows ProE would not know how to immediately model in SolidWorks, but if a resume says that there is experience in SolidWorks, you should be able to model something on your interview. We were recently looking for an engineering position that was posted as requiring hands-on basic metal working skills. The practical portion of the interview requested the interviewee to drill and tap a hole in an aluminum plate. The drill bit, drill, and tap were provided. Over half of the candidates really did not have a clue on what to do with the drill and tap. One actually just chucked up the tap in the drill and tried to drive it into the aluminum. It was actually a little scary.
That is not surprising; the Hands-on content of today's engineering courses has reached an historical low. It could be a result of people turning their interest from physical things to computer use (that is, from assembling say a Heathkit to playing with a computer, for example). The overwhelming impact of video games on youth and many adults had a negative consequence in regard to physical skills or abilities toward devices and hardware (non-computer, that is!).
For me, it is quite clear that a good engineer has to have some sense of connection with physical devices, equipment, tools and machinery. Being able to assemble and play with mechanisms, electrical or electronic assemblies gives the future engineer that connection. I used to say that there are two kind of engineers: "desk" ones and REAL engineers... At one time my boss (a Project Manager, more of the "desk" type) asked me to help him, because he had trouble with his car (the battery had died), and he wanted me to help him to jump-start his car with my cables. I said "shure, my pleasure! here are the keys of my car, go ahead, the cables are in the trunk"...
The poor guy hesitated and had to beg me to please go downstairs and do it by myself, as he was terrified with the possibility of getting "electrocuted" himself with the 12 volts. (Of course, I wouldn't had let him try, knowing him!). Amclaussen.
I like your approach, Greg. Candidates should definitely have a core understanding of the foundational principles and theories, and sure, a co-op and hands-on practical experience is a huge plus. But those coming out of school likely aren't going to have deep expertise in many of the skills needed in today's jobs. Yet as long as they demonstrate a hunger to learn and a willingness to role up their sleeves and dive right in, I think that's half the battle. I think some coming out of college have expectations that they don't have to start at the bottom and work their way up through hard work and hands-on training. They want the big job right out of school and all the perks that go with it.
Charles76, that's how I looked at it at first as well. If this test would have followed the suggestions of some of the other posters regarding figuring out how the candidate thinks rather than yes/no answers, they probably would have had a better passing score. Even asking a simple question such as "what is an ideal source" may have shown that the candidates are not missing as much as they seem to assume.
I also look for hobbies on resumes when I have to interview. I still do the testing and the interview, but I sometimes look at a weaker resume because the candidate may have listed a useful hobby. As you can tell by my screen name I tend to be partial to car guys. But this also translates into a person who has some basic hands-on skills that may not always be related to the target job. But hobbies are usually self taught or mentored. This means the person can learn!
Hobbies not only tell the person is capable of learning and pursuing them, but the fact that the candidate HAS some useful hobby, be it Auto mechanics, Model Airplane building, wood working, metal working, etcetera; tells a lot about the personality and reach of the individual.
Take the model airplane hobby for example; there is a lot of difference between a person that likes to buy and then fly them, to a person capable and willing to build them, because it requires dedication, perseverance, and some skills together with some knowledge. People that like to build things become much more capable because they tend to understand material properties and limitations, along with the best way to fabricate. And if the project built in the hobby fails, this gives the huge opportunity of learning why and how the project went wrong, teaching the individual a very valuable experience and the consciousness that he has to be careful and thorough if he wants to succeed. This creates an attitude that is the proper one when creating new devices or products.
[And yes... I also love cars, rebuild and modify them at my home, love airplanes and maintain one of them, love high end Audio, and most of my home equipment is home built; and love, really love tools and machine tools, and... and... and...]
I have to agree here. The question is not specific enough for engineering. You might have well have been asking "Where did they bury the survivors..."
The purpose of the interview is not to see how well the candidate guesses, but how well they think.
I put together a test of 20 questions for an engineering candidate. However, the purpose was not to give a piece of paper to the applicant and walk away, but to sit there with them and have them talk out their thought process for each question. I never graded the test on right answers but how they were thinking. Sure, we're all too busy to do this, but if you want to find a good candidate, you have to put some work into it. It's either that or hope you get lucky.
The problem with onesy questions like this is that they get out and then everybody, even the biggest idiot, knows the answer. Don't go for the answer, go for the thought process.
I like wise thought zero for the Voltage source and then the 5 ohms and wondered what was it connected to and thinking of the Thevin and Norton equivalents.
I had a question in an interview about powering electonics after the source is lost. There has to be enough capacitance in the circuit to hold up. But if the power is cut off at the lowest operating voltage spec. The circuit is nt longer operating in spec unless it is design for an even lower voltage cause the caps are at or lower that the cut off. Now you could have a circuit to pump up the voltage and it will last till it meets its lower operating limit. But that was not the point. So I did not get that position but did get another at that company. Guess the manager spent too much time in management. Cant create something from nothing.
A real power supply can appear "close enough to ideal" over the range it is used but things get goosy if you ask a really stiff battery (usually as close as we can get to an ideal voltage source) to provide a few mega amps for a millisecond to a few seconds, then eat the backwash politly. The ideal is supposed to be 0 ohms, but it does not exist in reality, so the question should travel to how close in what environments. Most of the supplies I deal with are great sources, up to their current limits, given a few milliseconds to respond, but are crappy at sinking enough current to hold the voltage in a large transient with lots of back current. And I am a physicist, a mostly self taught electronic engineer of last resort. Very right that most of our engineers do not have the physics they need and great gaps in their circuit theory. We are now, however, talking microwaves in the 300 GHZ range, and I admit my physics is very not up to that. And if you want to consider quantum computing and the like, I think we are hitting a "cusp" where the whole physics of our engineering is changing rapidly. Fun times if you are up for it. A very bad time for the US to be trying to shave costs on tech education.
I went to a career fair here at the university. Was starting to talk with one recruiter about their jobs offerings. The second question they asked was 'What's your GPA?' I told them, 2.97. He looks at me and says, 'We require at least 3.0.' I added, I got 2.97 while working full time!' They didn't care. So, they may have lost out on a good opportunity because a GPA was 0.03 too low. Oh well!
Maybe he did you a large favor... Imagine you went into that company, to find they aren't going to buy that badly needed $2,700 digital oscilloscope because their purchasing department said they were only authorizing $2,599... and you had to buy them the test leads and probes from your pocket!... and YOU DID!, only to find the model they finally bought is 100MHz short on bandwidth...
I am not too sympathetic to corporate world complaints of lack of qualified personnel. It is not neccessarily true that the point of college education is to support the corporate world. People go to college for a variety of reasons. The corporate world basically bailed out on training and developing people after the '90s. Besides, like everything else in business, it's all relative to competition. Hire the best people available for your purposes based on a comprehensive evaluation, not trick questions. If you are more successful at getting the best candidates than your competitiion, you will benefit in the free market.
LO!, all those decades ago when I was but a high school graduate preparing for my college experience, a sage (uncle) once told me something that I've NEVER forgotten ..... "the fundamental purpose of a college education is to teach you to THINK!" (He told me some other things too, but I can't repeat them in mixed company! Ha! Ha!)
I-B-M thought so much of this concept of thinking that for a long time they distributed throughout their facilities various-sized desk ornaments w/ the one word, "THINK" inscribed on the brass placard. And, anyone in this audience who is old enough should remember seeing photos of the I-B-M 360 main console w/ the THINK placard proudly displayed on the top surface.
Working in at a university, on research equipment, it is not always possible to know the answers to every question. When I became a 'working' manager of engineering support, I expanded my skill set by taking classes in supervision and management. Terrified at the prospect of being in charge of hiring someone, I applied my skills of troubleshooting and studied the interview process, asked peers a lot of questions, and learned a few do and don't s. The first hire was tragic. But I learned a lot. The second hire was a hit.
The questioned posed by Richard Nass' friend is a very good one, if you are looking at a bigger picture. I agree with other comments that the question is very unusual and not everyone would know the answer - the question is not well defined: 'What is the impedance?' The impedance of what? the voltage source? The circuit?
But I like this question and may use it myself. Why? When an engineer becomes a manager, not all but most, they apply what they know and interpret as important. And that is technical expertise in engineering. But that is not all there is to hiring someone. Keeping it short; Other important factors are compatibility with others, communications, stress response, etc. If the interviewee gave the answer the interviewer was looking for then all one knows is the desired answer was given. But, more can be learned about the interviewee if they do not know the answer; or give the wrong answer, are told the answer that was expected. How? Watch the person; do they become nervous(uncertain) or remain confident; argue the answer or discuss it; is there answer full of BS or a thought out 'I don't know'.
Where I work, the range of diverse information/knowledge that is needed is not likely to be found off the street. So, I look for drive, motivation, open mindedness, communication without argumentation (I want credit for that phrase), a willingness to learn... I would use this question, not as an engineering question, but as a rhetorical question. It is not the answer to the question that I would be interested in, especially if the knew my answer. It is their response to it when they don't know my answer.
Apply your diagnostic and troubleshooting skills to the interview process and explore new applications for those skills. Great engineers don't have to know everything.
What you are seeing is the result of the current move to send everyone to college. So the college waters down the classwork so that they can keep the students happy and the money flowing in.
The colleges don't see their market as the companies these students are going to work for, they see it as these stdents who are dumping large amounts of money to get a piece of paper.
And the expectation that students will leave college with highly usable skills is also unrealistic. The engineering field is so broad that the odds of having a graduate arrive with your skillset is about nill. If someone from potential employers isn't going to the colleges looking for future employees they students will have no idea what areas to specialize in and thus their general training may not spend much time in your field of work.
Oh - And while it might be nice to blow a potentaial applicant out of the water with your little test, does it really have anything to do with the real world? Or does it just make the old guy feel very superior to those wet behind the ears kids?
I have a degree in COmputer Science and Electrical Technology. I have used some of the computer stuff, but a couple years out of college most of the technology had been replaced with newer stuff and I was learning on the job. And the electrical Technology? most of the theory is nice to know, but most of the real work uses very little of that theory. If you want recent graduates to have some skills that you could use in your company, have some contact with them while they are still in college and give them some ideas for projects that would give them some skills that you could put to work. They would learn something useful, and you could get some employes that are partially prepared for what will get thrown at them on the job.
The reality of the 21st century economy is that some level of post-secondary education (whether a bachellor's degree, an associate's degree, or a professional certificate of some kind) is necessary if you want to make more than minimum wage. In spite of the high unemployment rate, many skilled manufacturing positions are going unfilled because of a lack of qualified candidates. There is an article in this month's Modern Casting about this.
The problem is not so much "everyone going to college;" making more education available to more people is a good thing, not a bad thing. In fact, we need to educate more people, if we want to keep up with countries like China and India. But also we need to have a national discussion about the goals of education. Widely-held views about the four-year college experience need to be re-evaluated.
In our country's past, college was essentially a rite of passage for the children of the rich, and its main purpose was not to educate, but to form and maintain an elite. That's why, for example, prior to World War II, many prestigious East Coast institutions had quotas to limit the number of Jewish students -- they were not primarily interested in training the brightest minds, but in maintaining the old New England aristocracy.
Many aspects of the four-year college experience today are leftovers from that time. The drinking and partying made sense for students whose futures were already assured thanks to their parents' wealth and connections. They don't make sense if the primary goal is to educate.
I think many students are better served by two-year institutions than four-year institutions. As the Modern Casting article points out, many students with two-year technical degrees can make $60,000 a year straight out of school, while some students with four-year degrees can't even get jobs.
The Modern Casting article nails it. Part of the problem is that a whole generation of Americans raised their kids to steer clear of manufacturing. To them, manufacturing meant dark, dirty and dumb. So now, even as manufacturing offers relatively high-paying jobs for educated people with strong math skills, many are still insisting their kids go to four-year colleges and learn something that may be far less marketable.
I don't use (or respond to) trick questions in interviews. Management that needs to rely on tricks in order to interview candidates, also tend to create a poor work environment.
This problem is across all industries today. I talk to university professors who lament the lack of critical thinking amoung their students. Recruiters feel like gold miners digging for the right candidate. So far, I've heard a lot of complaints but no one offers solutions or even help. In the current economy, there's no budget or time to train on the job. Apprenticeships and mentoring could make a big difference.
NadineJ, a trick que4stion depends on one's point of view. In my environment, 'customers' come in and ask questions that are confusing and lacking in information. It is important to know how someone reacts and responds to such questions. Asking how someone would handle the situation is different than seeing how they handle it. As in my previous post, it is not the answer that I am concered with, it is the interviewee response.
Apprentice ship and mentorship are the keys -- but that is the job of industry, not the university, in my opinion.
Universities are fantastic at producing grant-proposal writing academic geniuses, but not practical engineers. That is well and good, we need strong academics who know how to work that system and get that grant money. More power to them.
But it is engineers in the field that know what it takes to be an engineer -- how in the world would an academic know that? Professors in Universities have pHD's in their field, they write thesis papers, manage research projects, teach classes, attend conferences, and manage grad students kluging projects together in under-funded labs. Professors don't design product after product. They don't have 20 years of engineering experience to pull from when they decide what that student really needs to know to be an engineer.
It is time for industry to step up. If we have a lack of qualified engineering candidates it is because industry has not come to understand what all of we working engineers know -- engineers have to be learning every day or you fall behind. Some of us are lucky enough to work at companies that know and support this, who bring in interns for on the job training, who send their employees to technical seminars and classes, who avoid laying off their valuable, trained work force. At my company we don't have a problem finding qualified candidates, because we don't lay off good learners and we have a pool of ex-interns to hire from.
Perhaps if I clarify my work environment; I work in a chemistry department maintaining research equipment that spans decades of technology. Vacuum tubes, anyone? Money is not available in the quantities needed to update nor keep up to date, the equipment. There is also a need to understand across several disciplines. It is also multicultural and the majority 'customers' (grad students), are coming and going. Generally, chemists don't know electronics and physicists think they know. As a result, requests can come in that make absolutely no sense. And almost always, it needs to be explained why without offending someone. And sometimes, we don't have the answers but we have to go find them, no choice. Learning the engineering is simple, trying to fix an employee causing interpersonal problems is not simple, easy or maybe even possible. I use questions where the answer is only part of what I look at - or the answer is irrelevant and my observation is of interest. Basically, all the opinions given are right for different situations and work environments.
I agree with the posters who say it's not a valid question. The "ideal" voltage source is an abstraction used to teach first-year (or perhaps second-year) undergrad students the basic concepts of circuit analysis; they will never encounter such an animal in real life. A student with an amazing memory will remember that factoid (the internal impedance of an ideal voltage source is zero), a smart student who doesn't remember will think about the problem analytically and derive the answer, a brilliant student will ask "impedance of what?" because the question isn't clear and it's always important to gather all available information about a problem before attempting to analyze it.
I once worked with a PhD (specializing in radio-frequency eletromagnetics) who didn't understand the basic principle of a radiating aperture - the question came up because she didn't understand how a dichroic plate worked. She was probably far smarter than I, but didn't understand one of the most basic concepts of microwave radiation, her chosen field. Based on this, I wouldn't have hired her, but someone did.
I've also worked with recent EE grads who couldn't do basic circuit analysis. Doesn't mean they weren't smart, or they couldn't do the job they were hired to do.
I've learned you have to be wary of relying too heavily on answers to questions on a screening exam; a lot of people have skills that can't be measured that way.
Before I retired from GE, I volunteered to interview graduate engineers seeking employment with the company--GE Appliances, Louisville, Ky. I was one of several "screeners" that would sit for the interview and pass judgment on the candidate and his or her possibilities for success. GE Appliances, like most companies, can be a pressure cooker and few entry level engineers are ready for what they receive after employment is offered and the job duties begin. One of my pet peeves was the inability of some applicants to effectively communicate. I was blown away by incoherent sentences, sloppy thought processes and most of all, vulgar language. I don't know where along the way anyone thought communication was not part of the engineering process. Another pet peeve--you would not believe the number of times a candidate was late and / or did not show at all. Generally they wanted a second chance and sometimes they presented a valid argument. Oversleeping when the interview was a 1000 A.M. did not make the grade. I was left with the opinion that recent graduates had been accustomed to being catered to. That simply did not occur at GE.
That kind of trick interview question is as old as Nodal Analysis and works great. The function is to distinguish those who pass engineering by rote memorization from those who really think. But as a janitorial service manager once observed, only one in ten candidates are worth anything -even for menial work. For better luck try Cal Poly, SLO. The hands-on orientation of the instruction ensures higher odds that the capable candidates have opportunity to acheive genuine understanding.
As the author notes; "So far, no one has answered correctly." So what is the value of the question, other than feeding the ego of the questioners?
To then tie such a useless question to the state of education, hardly strikes me as sound engineering on the part of the many people dissing modern education here. A statistician would laugh at this misdrawn conclusion.
I'm no EE, but my thought was immediately 5 ohms too. Seemed like a simple application of the impedence formula the total opposition to alternating current by an electric circuit, equal to the square root of the sum of the squares of the resistance and reactance of the circuit and usually expressed in ohms. If the 'total' opposition to current in a circuit with an 'ideal' power supply is zero, current is infinate. In this case, it's 2 amps, isn't ?
I disagree. Its a good weeder question that culls out the mediocre 90% that don't think. Another one along the same lines it a current source into a capacitor. The non-thinking people will draw an exponential curve from rote memory.
The people who fail those kinds of questions have weak independent thinking skills. Yes, a savvy manager can train them. But they will never excel on their own. In an R&D environment that requires creativity, resourcefulness, analytical refinement and the ability to think independently, they will never be more than mediocre. The design won't be right. They won't catch the bugs. The product will fail on the market. And the company will lose business.
Even worse, when they advance into management, they'll really mess things up because they'll direct business impulsively based on intuitive presumption instead of on disciplined analysis of facts.
I got the answer right and in 2 seconds. Its obvious.
Hi Ken E, good questions. The practical characteristics and skills these kinds of trick questions demonstrate are the tendency and ability to solve problems from clearly understood root principles. In an R&D setting, thats precisely the kind of guy to hire because he'll be faced with weird and unprecidented problems on a daily basis.
Basically, if the candidate can't handle this itty bitty simple ideal trick question, then there is no way he'll achieve excellence in an R&D setting where he'll be faced with tougher, more complicated curveballs in the real and much more messy world.
About a year ago, I watched a major R&D project fail and burn-up a pile of money because it was staffed by precisely the kind of engineers and managers that fail this kind of trick question. A first 1A version of the product had a 4x shift in the test current to 4A from 150C to -55C. Nobody was capable of thinking through that the 40A version would require a test current of 160A at -55C. This is just one example of the many areas where the team fell down in elementary ABC engineering tasks because the company hired mediocre people.
What the trick questions do is to screen out the medicre candidates early in the interview process so one can conentrate the on-site interviews on the really good people.
Sorry if this sounds elitist but hiring is like picking people for a neighborhood softball game -the best and brightest get picked first because one is playing to win. The difference is that the stakes are higher because if the company looses then all the employees lose their jobs.
@PwrGeek: How confident are you that success on a single question like this is an accurate predictor that a candidate won't make the kind of mistake you describe? In my opinion, it's a weak indicator, at best.
The engineers in your example were aware of the test current shift in the 1A product, but they didn't think through what it would mean for the 40A product. Apparently, nobody asked them, and they didn't ask themselves. So it seems that it was a failure of imagination (at a forehead-slappingly basic level), not a failure of knowledge.
I think you'd be more likely to identify candidates who would be successful in this sort of situation by paying attention to what questions they ask, rather than how they respond to your questions.
Obviously, nobody is arguing that you should hire mediocre people. But "smart" and "clever" are not always the same thing. Asking trick questions helps to determine which candidates are clever. Listening to the questions candidates ask helps to determine which ones are smart.
Hi Dave, One never asks a single question in an interview. Instead, there is a pattern of questions to assess... 1.) How the candidate thinks, 2.) What the candidate knows. The trick questions are one quick and effective means of differentiating people who think from the rote memorization robots.
In the long run, how the college educated candidates think is more important than what they know -both for the company and for themselves. The university provides both candidates with basic training. Beyond that, I have the competency to train either candidate in what I need them to know. But the independent thinker will grow beyond the training and achieve success when faced with new problems but the rote memorization robot won't. And, the robot is at a career disadvantage because 9/10 engineering managers DON'T have the competence or patience for training.
Ultimately, the distinction is intellectual discipline vs. intellectual laziness. Like a virtuoso musician or professional athlete, the thinker takes initiative to maintain an intellectual edge through constant study, review and practice. Excellence is a disipline.
The question is really very simple and there is no excise for an EE missing it. Upon missing the second question of that nature, the job opportunity is lost. Sorry, but its like a car mechanic not knowing what tool removes an oil filter, or an accountant not being able to add -it betrays a fundamental deficiency in the skills of the trade.
BTW, I'm not Rich's contact. I'm just a random Silicon Valley Analog/Power Temp Engineer with prior experience founding a couple of startups.
And one more thing, before I'm distracted again (I have my IT hat on tonight doing server maintenance and I'm writing while monitoring update installations).
The engineers and managers in the example are poster children of why hiring morons is bad for business. I told them. I sketched on the white boards. I showed excel charts of test data and they just stared vapidly. I did everything short of beating it into their thick heads with a bat and they never understood. They could not grasp why one couldn't use banana plugs and 18AWG wire for 160A. They failed to start early to counter the longer lead times of the wire, connectors and high-power test board components. With the professional ones, the shortcomings were surmountable through teamwork. But half were too inept even for that. They're precisely the kinds of people the trick questions are devised to root out.
Steve Jobs had interesting terminology for the flood of such people that inevitably pours into a company as it ages; He called it the "bozo explosion". Get the first few in, interview standards decline and in they all pour. Then the company fails in buiness.
The biggest flaw in the current university system, certainly in UK, is the extensive use of "modular" courses. Students just get the habit of focussing on this semester's modules and when they pass them, they immediately forget the lot. By the end of three or four years they have apparently passed enough modules to graduate but they just don't get the whole picture. Hence the generally poor thinking and problem solving skills. I have rounded off 45 years of electronic engineering by teaching part-time during the last twelve years so I have seen this first-hand. Alas I'm not senior enough to change the system, that's well beyond my pay-grade unfortunately.
There's also too much reliance on computer simulations. A computer can't simulate the burning sensation and smell when you pass that 160A down the 18AWG wire!
Dave, missing a single question like this may not mean that an applicant is unqualified or incompetent. After all, everybody tends to be just a little nervous during an interview. On the other hand, repeatedly failing to notice significant details before claiming to solve a problem (the classic "Ready! Fire! Aim!" sequence)) certainly should raise a red flag about whether an applicant will be a net gain or net loss to the team.
It's been more than a quarter of a century since my engineering student days ended far short of graduation, but seeing a question about a circuit consisting of 2 devices in parallel was enough to make me stop and think "Wait a minute!" instead of "Too easy!" If I consider my knowledge of circuits to be not much better than an electrician's apprentice, what should I demand from folks who are applying for a position which will require them to identify and solve much more nuanced problems than this?
I agree, Dave. Most of the people who I know that do hiring prefer to find out about the characteristics of the individual. These days, many companies are looking for people who've shown a willingness to learn and a proponsity to stick around for a while.
I figured out the answer, but in an interview I would have asked if it was a theoretical perfect power supply, or a real one. That would probably have told them what they were looking for. I have had a few questions on interviews, and evidently answered them correctly. For one, I gave a short correct answer, then on my way home I realized that was not what he was looking for. So in my "thanks for the interview" email I explained what the full answer that he was looking for was. I did get the job. The worst question was in another interview, they showed me a one transistor amplifier and asked what the gain was. It was my very first engibeering position interview out of school. I said that I required more information to give a correct answer. I got the job anyway. Evidently I missed the trick on that one.
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