Bob Posted March 4, 2011 Report Share Posted March 4, 2011 I have spent my first semester in IB, done a couple of labs, but I haven't figured the perfect formula to get high marks in labs.My best two DCP labs scored 6 and 5, and two 5s for my CE labs. I did one design lab recently and I got a three. I have read the requirements and the mark scheme, but there is always something to pick on in my labs.I have talked to my teacher , but ugh, I am still confused. I really want those 6s... How to improve? Any help is appreciated BTW, what do you guys write for the evaluation of a lab?Sometimes I couldn't find any possible improvements in the lab... and thats usually why I don't get a six in my CE labs. Reply Link to post Share on other sites More sharing options...
Keel Posted March 4, 2011 Report Share Posted March 4, 2011 I have spent my first semester in IB, done a couple of labs, but I haven't figured the perfect formula to get high marks in labs.My best two DCP labs scored 6 and 5, and two 5s for my CE labs. I did one design lab recently and I got a three. I have read the requirements and the mark scheme, but there is always something to pick on in my labs.I have talked to my teacher , but ugh, I am still confused. I really want those 6s... How to improve? Any help is appreciated BTW, what do you guys write for the evaluation of a lab?Sometimes I couldn't find any possible improvements in the lab... and thats usually why I don't get a six in my CE labs.Hi,I can't really tell you the nitty-gritty aspects of getting 6s for IAs in physics becaus I don't actually take the subject. But as there are some similarities between the IAs of the three sciences maybe I could give you some guidelines and let some physicist fill in the nitty-gritty. In your design what you want is a practical, doable experiment. This is then to be expressed in a question usually "How does .... affect ...?" You then want to list your independent variable (how it will be varied), your dependent variable (how it will be measured), and your control variables (how will you control them?). In the 'procedure' part, you basically want to create an idiots guide to the experiment giving extreme detail in the method and covering even the most basic of actions (such as "start the stop-watch") You also want to give a list of the apparatus you are using (including size) and possible a diagram of how they will be used. You also want to put in a blank table of results or blank graph with the axis labelled accurately.I can't comment on the data processing as I guess it would be quite different from chemisty, but in your conclusion you want to state the answer to the question (including the error) and state how you reached such a conclusion ie. the 'science' behind the experiment.I think the evalutation has the most similar aspects in all three sciences. First you take your obtained value and calculate the % difference with a literature value. This will form the basis from which you can determine how accurate the experiment was. Then you subtract the error due to imprecision in equipment to find the % caused by systematic error. You can then comment on this and say how inaccurate or accurate the experiment was. You then want to state how the experiment could be improved and this can be split into two parts. The first is reducing random uncertainties. Go through each equipment and state the error it (could have) caused in the experiment and propose an improvement (measuring cylinder to pipette) ect. You then want to comment on the systematic errors (ie. the limitations of the experiment not caused by imprecision). You want to state whether the systematic error was major or minor, whether it shifted your obtained value up or down. Then like in the previouse case, state an improvement (eg. heat loss, major error, caused obtained value to be greater than actual, conduct experiment within an insulative container). You may also want to suggest repeating the experiment more frequently to obtain more results and to cancel out random uncertainties.I hope this helps, but bear in mind this was written by a chemist (we are not to be trusted). There are some useful reasources in the chem section of the science forum regarding IAs which might help you. Good luck with your next IA! 1 Reply Link to post Share on other sites More sharing options...
Bob Posted March 4, 2011 Author Report Share Posted March 4, 2011 (edited) Keel: thanks a lot! Yes, the design part s such a hassle; I have tried my best to produce 'for dummies' kind of write up... but my teacher always finds my blunders... Do I also need to explain to an idiot in my introduction part? (edit: wasnt speaking english lol) Edited March 4, 2011 by Bob Reply Link to post Share on other sites More sharing options...
Keel Posted March 4, 2011 Report Share Posted March 4, 2011 Do I also need to an idiot in my introduction part?Well normally my 'introduction' just consists of the different variables, this isn't as easy as it sounds because most people get caught out on the control variables when they forget to add the simplest of controls eg. time or temp. Or alternitively they try to over complicate things and make the controls absolutely impracticle eg. conduct the entire experiment in a water bath when they could simply stated that 'the experiment will be conducted at room temperature'. For some reason all the bio people in my class like to write a little introduction in the begining explaining what a catalyst is or how hydrogen peroxide is formed (maybe its a requirment in bio?) but this is certianly not a requirment in chemistry and is a waste of space, you actually risk stating something wrong and getting it marked down as 'factually incorrect'. So I guess the rule of thumb is to keep every thing simple, precise and neat. This goes for language, choice of equipment and layout of ure IA (try to do things in tables eg. Column 1: Control variables Colum 2: How will they be controlled?). Reply Link to post Share on other sites More sharing options...
Bob Posted March 4, 2011 Author Report Share Posted March 4, 2011 Do I also need to an idiot in my introduction part?Well normally my 'introduction' just consists of the different variables, this isn't as easy as it sounds because most people get caught out on the control variables when they forget to add the simplest of controls eg. time or temp. Or alternitively they try to over complicate things and make the controls absolutely impracticle eg. conduct the entire experiment in a water bath when they could simply stated that 'the experiment will be conducted at room temperature'. For some reason all the bio people in my class like to write a little introduction in the begining explaining what a catalyst is or how hydrogen peroxide is formed (maybe its a requirment in bio?) but this is certianly not a requirment in chemistry and is a waste of space, you actually risk stating something wrong and getting it marked down as 'factually incorrect'. So I guess the rule of thumb is to keep every thing simple, precise and neat. This goes for language, choice of equipment and layout of ure IA (try to do things in tables eg. Column 1: Control variables Colum 2: How will they be controlled?).Ah! This must be the case, cause the design frame I was given is actually work of my physics teacher's wife, who is teaching bio in ib, lol!I must have taken the wrong approach.For chemistry, it is not necessary to 'explain' the experiment (i mean like the theories, concepts and stuff)?I will find my teacher again, thanks for the tip! Reply Link to post Share on other sites More sharing options...
Keel Posted March 4, 2011 Report Share Posted March 4, 2011 Ah! This must be the case, cause the design frame I was given is actually work of my physics teacher's wife, who is teaching bio in ib, lol!Haha yeah there are a lot of those teachers in my school too.For chemistry, it is not necessary to 'explain' the experiment (i mean like the theories, concepts and stuff)?I guess the theories and concepts are implied in your method and the 'design' of the experiment? For example if your question was to find out how the increase in the mass of Mg affected the volume of gas produced when if was reacted with 10 cm3 of 0.1M HCl and you chose to vary the mass from 5g to 10g with 1g intervals (independent variable) it would show the lack of understanding of 'limiting reagents' and molarity as there will be excess Mg and your experiment is pointless. So yeah you would need to clarify that with your teacher. Reply Link to post Share on other sites More sharing options...
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