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I know the material inside and out, but then make dumb mistakes on tests

  1. Nov 1, 2006 #1
    I know the material inside and out, but then make dumb mistakes on tests....

    I learn the material backwards and forwards, understand all of the concepts, but then when I take tests I make little slip ups that cost lots of points, like units conversions or I screw up obvious simple little formulas. To show that I truly know the material, I rework the problems in my head after taking the test as I walk home and realize all of the mistakes I made, and I realize why certain answers didn't work out right...

    For instance, I made a really really dumb mistake on today's optoelectronics test....I calculated wavelength by taking the reciprocal of frequency....since I am a bad test taker I overlooked this mistake...I did not realize I made the mistake until after the test was over and I was walking down the hallway....

    And don't tell me it's because I didn't work enough problems or did not read the assigned readings or because I didn't understand the material....this is not the case. I am going to talk to the prof about it tomorrow...maybe he can go easy on me...I dunno.

    You might ask, "how the hell can you think wavelength = 1/frequency, under ANY circumstance??" Well, I am a bad test taker....under other circulstances I would not make that error.

    Honestly, grades are useless methods for benchmarking a person's understanding and mastery of a subject.

    Does anyone have any advice?
  2. jcsd
  3. Nov 1, 2006 #2


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    It sounds like you're just nervous, but I unfortunately really don't have any advice on how to help you be less nervous.

    The good news is that many graders don't kill you for making a single small mistake, even if that mistake carries on to ruin the rest of the problem.

    - Warren
  4. Nov 1, 2006 #3
    Well, in this particular problem, I ended up with a phase shift as my answer, which was around 10^8 radians....lol...it should have been on the order of 0.4 radians or so. That is a BIG error....

    The answer is much more reasonable if I found the wavelength by saying c/f, and not 1/f....

    And the thing is....I usually feel rather calm while taking tests.
  5. Nov 1, 2006 #4
    Check your answers until you become more comfortable, if time permits. Think if the answer is even in the right ballpark, I suppose.
  6. Nov 1, 2006 #5
    well, yeah, my answer was obviously not in the right ballpark, and I looked over my work a couple times but stupidly did not notice the error I made....which would be obvious under normal circumstances.

    I dunno....this kind of thing is just really starting to frustrate me....I study hard, and it often seems like it is for nothing, because people don't look past grades, and if they wanted to look past grades there's not much else to look at....

    And many of the professors think you're incompetent because of the grades you get on tests....this is very depressing.
    Last edited: Nov 1, 2006
  7. Nov 1, 2006 #6
    Sometimes I have this problem as well, so I made a little notecard of "rules" that I must follow when I take a test.

    1. Read each question carefully, underlining key words and ideas. That way you answer the question that is being asked, instead of misreading the question and making up your own.

    2. Identify the "core concept" of the question. By this I mean try to get in the professor's head. They don't ask exam questions to see you calcuate things, they ask exam questions to see if you understand the underlying concepts.

    3. Make sure that the professor can see that you understand the "core concept" in your answer to the question. If the professor sees that you understand, he/she is much more likely to be forgiving for little mistakes.

    4. Check your equations for the proper units and limiting behavior. Your mistake of thinking that the wavelength was the inverse of frequency would be caught here, because you would notice that your units were seconds instead of meters.

    5. Apply physical intuition to your final results. Do they make sense physically? This saved me on my last exam. I had an answer of around 500 MV for an accelerating voltage, and this was two orders of magnitude higher than anything we had been dealing with. My intuition told me the number was too high, and I went back and found that I had made a mistake in my calculation.

    Since I started doing these things I have made far fewer dumb mistakes on tests. Granted, you don't always have time to do all these things, especially in an hour exam, but you should try your best to analyze all your answers in this way.
  8. Nov 1, 2006 #7
    excellent advice. Thanks a lot unit circle.
  9. Nov 2, 2006 #8
    I would say that if your answer is obviously wrong, such as was supposedly the case here, and you can't see your error right away. Wait until you finish all other questions and then redo the question from scratch. Thats what I'd do. Although I don't know how hard your questions are (how long they take) :P.

    Perhaps even try to do it using a differant method?
  10. Nov 2, 2006 #9

    You could also write an explanation about your wrong answer on your exam. I do this a lot. If I know an answer is wrong, I'll write out why I think it is wrong and what I think the real answer should look like. This may not save you all of your points, but sometimes it will let your professor know that you are thinking about a problem, or at least capable of doing so, and they will grade that problem easier.

    Also, always right what you are doing for each step. That way they will give you more extra credit for the smaller steps, and focus less on the final answer. This has saved me numerous amounts of time.

    Basically, the more you give your grader to deal with, to look over and realize you are capable of thinking reasonably about a problem, the less emphasis there will be on a perfect solution. This assumes, of course, that you are doing some of the problem correct and just making small formulaic mistakes.
  11. Nov 2, 2006 #10
    well, I put a couple question marks next to the answer....maybe this will indicate that I knew the answer was obviously wrong....lol, I got a phase angle of on the order of 10^8. lol
  12. Nov 2, 2006 #11
    You probably do not know it all perfectly. If you did, you wouldn't overlook anything. It is imperative that you do not rush it on tests. That is the largest source of errors for most people.
  13. Nov 2, 2006 #12
    excellent topic. I am 27 and in the middle of a second bachelors on physics. I flunked out of the physics program the first time, and had to choose a different major. The reason I flunked out was due to test anxiety, so I am very familiar with making stupid mistakes. However, the second time around I am having a completely different experience. I have a 4.0 in my second year of the degree. I was very happy to see unit_circle's advice, becuase that is EXACTLY what made the difference. I apply those same rules to taking tests, with dramaticly better results. The main thing to keep in mind is that the professors are not out to get you, usually, test questions are quite simple and straigtforward (something you can do easily in an hour or two without a calculator). You just have to pinpoint the concept of the question, which you know. Once you understand the concpet, you will have plenty of confidence on how to proceed and usually avoid making stupid errors. Ask yourself, why is the professor asking this? And assume that the professor is being as straightforward as possible, there are almost never any trick questions.

    Interestly, I have also struggled with mild dislexia, and I think a lot of physics/math majors have similiar issues. This can often lead to severe test anxiety. And I think this anxiety among many students can be one factor for why averages on physics tests are so low. I know two other students in my program who are very smart and from converstions over coffee, I have gathered that they might even have a better grasp of the material than I do, but their grades are miserable because they are always assuming the test questions are much more complicated, or because they get nervous, etc.
  14. Nov 2, 2006 #13
    I have a simillar problem - I may know the material well, but my ability to do arthimetic/rearrange equations/do simple calculus always deserts me in exams. Coupled with my usual problems with copying accurately (either from my head, or from paper), I'm a bit of an exam disaster.

    I suspect it's just down to bad exam technique, because it means I have to take so much more care that what I'm putting doesn't get away from me, and is exactly the same as what I wanted to write. As others have said, the following things help me:

    *If you suffer from exam nerves, spend the time while they're distributing papers/yattering on about how much time you've got to pray/mediate/take deep breaths/do calming exercises, or whatever else you normally do to get a grip of yourself

    *Remember that, whatever's riding on it, it is ONLY a exam, and your life will still go on if you fail.

    *Look through the paper for 5 minutes beforehand. As you do so, jot down the equations/concepts you think you'll need on the question paper (if allowed) or on the provided area for rough work if you can't.

    *Start on the easiest question, for a beginning-of-exam confidence boost

    *Then do the hardest - you'll be freshest at the start, and less likely to make dumb mistakes, and work down to the easier ones.

    *Check everything twice, including calculator sums. If you don't have a calc in the exam, don't rely on your mental arithmetic - do it with pen and paper the way you were taught in primary school. Double check your equations for the correct dimensions, and your answers for the correct units.

    *if you think something is wrong, and your institution/marker encourages this, note it down beside the answer - you may get a mark for knowing you'd messed up, but not having the time to correct it.

    *follow unit_circle's advice as well (they summed it up pretty well)
  15. Nov 2, 2006 #14
    This is matter of personal preference and everyone is different, but I generally work the from the easiest to the hardest problem. I start on the first problem, if I don't know how to attack it immediately I move on to the second, and so on. My philosophy is to get the "for sure" points first.

    Also, if the exam lists the point value of the questions, you should take that into account as well. Don't waste a lot of time working on problems with few points.
  16. Nov 2, 2006 #15
    I know that units have been mentioned already, but when you finally reach the end of a problem and plug in values, write down your units in your formula (as opposed to the numbers alone). That little tidbit has saved me so many times it's not even funny. That way, when you see that you're calculating sin(1.37 mm), it's obvious that you've made an error. In your case, seeing that your unit of wavelength is seconds might be a problem.
  17. Nov 2, 2006 #16
    yeah, I get careless and frequently drop units. I will start writing units from now on.
  18. Nov 2, 2006 #17


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    I also tend to do an exam from front to back -- and I tend to move to the next problem as soon as I become stuck, and don't expect to become unstuck quickly.

    Then, I repeat the process, but allow myself more time to be "stuck" each time before moving on.

    Then again...

    (Just to clarify, this isn't an "easy"/"hard" thing -- I will happily do a hard problem the first time through if I keep getting ideas on what to try next and don't sit idle)
    Last edited: Nov 2, 2006
  19. Nov 2, 2006 #18


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    work more problems. make and take practice exams and set times for them. practice under exam conditions. when you get to ane xam the questions should be ones or simialr to one you hVE WORKED BEFORE under the same conditions.
  20. Nov 2, 2006 #19
    Who honestly has the time to do all this (make and take practice exams)? I just dont see this happening and think its a bad way to study. sorry.

    For me, my number one thing is don't skip a problem. If I get nervous and skip a problem, I set in my mind that it is 'hard' and go to another problem with that bad feeling of a 'hard' problem waiting for me. So I push through and do the problem, and realize it was not that hard afterall. Then the rest falls in place. But when you get stuck and move on, your screwed.

    Oh, and always write super neat, I mean SUPER NEAT

    I get very nervous before an exam. Usually the night before I dont really fall asleep but am in a daze going over problems in my head. Its not until I finish the first problem that I am in my zone and thrash through the exam.

    You have to find what your 'zone' is and how to get there as fast as possible.

    During my EE exam, I could not get into my 'zone' and was like, ooooooooo sh!t, this is going to be bad. I felt like I was wasting time and not getting anywhere with problems and skipping around. Very bad place to be on an exam, and it was not because I did not study.
    Last edited: Nov 2, 2006
  21. Nov 3, 2006 #20
    usually my hand is shaking violently during a test though, and as a result my handwriting is terrible. Also, on this last test I made a million mistakes, so I had traces of things that I erased everywhere. This test was far from neat.

    However, I talked to the professor about the dumb mistake I made and told him that I'd get the right answer to the problem using my method if my wavelength calculation was correct and he said he'd only take a couple points off. So, since I didn't do one of the 4 problems (which, after talking to the prof about it, he and I realized I really knew most of the answer, but just didn't write anything), and he is taking about 2 points off on the problem I screwed up, I am likely to get around a 73%. Not too bad, and I have a chance to fix that grade....I still have a shot at an A, so I am not too worried.

    The good thing is though, I answer every question this professor asks in class and I am always talking about the course subject matter with the prof outside of class so he is aware that I take the course seriously. I hope this may sway his grading a bit in the end....
    Last edited by a moderator: Mar 25, 2008
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