Ia & Labs Rubric And Checklists.pdf

           

IBDP Chemistry IA and Lab Report Rubric & Checklists This document should be referred to every time you have to write a lab report.

Adapted from Angelique Hiscox on Chem OCC (2015) and American International School of Bucharest

     

1  

 IBDP  Chemistry  Internal  Assessment          

• •

• •

•

The  major  piece  of  assessment  in  Group  4  subjects,  in  addition  to  the  exams,  is  the  Lab  Investigation.       The  final  IA  task  (a  10  hour  individual  investigation,  chosen,  designed  and  carried  out  by  you)  to  be   completed  in  Grade  12.     It  will  count  as  20%  of  your  final  IBDP  Grade.     All  labs  and  reports  you  are  asked  to  complete  in  this  class  are  designed  to  help  you  build  the  necessary   skills  to  carry  out  this  task  to  the  best  of  your  ability.       The  final  IA  Lab  Investigation  is  marked  using  5  criteria:       Personal  Engagement     Exploration     Analysis     Evaluation     Communication    

  •

 

 You  will  have  opportunity  to  practice  each  criteria  on  its  own  or  in  combination  with  other  criteria  as   progress  through  the  course.    

Personal  engagement    

 

2  (8%)    

• •

 

 

Exploration     6  (25%)    

 

 

Analysis     6  (25%)    

 

 

Evaluation     6  (25%)    

 

 

Communication     4  (17%)    

 

 

Total     24  (100%)    

      This  document  details  what  is  required  to  achieve  the  best  grade  possible  for  each  criteria.     It  is  long,  but  in  the  beginning  just  focus  on  the  criteria  being  assessed  for  each  lab.    

                         

2  

         

                                        https://i-­‐biology.net/category/ibdp-­‐biology/lab-­‐work-­‐internal-­‐assessment/                                    

             

3  

Personal  engagement      

This  criterion  assesses  the  extent  to  which  you  engage  with  the  exploration  and  makes  it  your  own.  Personal   engagement  may  be  recognized  in  different  attributes  and  skills.  These  could  include  addressing  personal   interests  or  showing  evidence  of  independent  thinking,  creativity  or  initiative  in  the  designing,   implementation  or  presentation  of  the  investigation.           Mark Descriptor     0

The student’s report does not reach a standard described by the descriptors below.

1

The evidence of personal engagement with the exploration is limited with little independent thinking, initiative or creativity.  

The justification given for choosing the research question and/or the topic under investigation does not demonstrate personal significance, interest or curiosity.  

There is little evidence of personal input and initiative in the designing, implementation or presentation of the investigation. The evidence of personal engagement with the exploration is clear with significant independent thinking, initiative or creativity.

2  

The justification given for choosing the research question and/or the topic under investigation demonstrates personal significance, interest or curiosity.  

There is evidence of personal input and initiative in the designing, implementation or presentation of the investigation.

                                 

This  section  is  very  much  tied  to  the  exploration  section  rather  than  being  a  section  in  its  own  right  in   your  lab  report.  Most  of  the  evidence  for  personal  engagement  will  appear  in  your  introduction  or   background  information  and  in  your  method.     When  deciding  on  a  topic  of  investigation  research  should  first  be  done  to  make  sure  there  is   enough  literature  to  support  your  investigation.  The  topic  chosen  should  be  unique  and  your   introduction  should  show  how  the  topic  is  relevant  to  you.  Third  person  is  the  correct  form  for  a   scientific  paper  but  first  person  can  be  used  in  one  paragraph  to  show  your  connection  to  the   topic.     When  choosing  a  research  topic  and  writing  an  introduction  ask  yourself  the  following  questions?     • Is  this  experiment  just  replicating  another?  –  if  the  answer  is  yes  then  its  not  suitable   • Is  this  topic  worthy  of  investigation?  -­‐-­‐-­‐  if  the  answer  is  no  then  its  not  suitable   • Is  there  enough  literature  to  support  my  investigation?  –  in  text  referencing  should   be  used  with  a  sufficient  number  of  sources  of  information.     Writing  Research  Questions   The  Research  Question  should  be  clearly  stated  with  the  reason  for  its  investigation,  as  part  of  the   introduction.  The  research  question  should  be  sharply  focused  and  refer  to  both  the  independent   variable  and  the  dependent  variable.   Poor  Research  Question     • To  investigate  the  impact  of  concentration  on  reaction  rate”  

 

Good  Research  Question     • To  investigate  the  impact  of  the  concentration  of  hydrochloric  acid  on  its  reaction     rate  with  calcium  carbonate  by  monitoring  the  pressure  over  time  as  carbon     dioxide  is  produced.        

4  

Exploration    

This  criterion  assesses  the  extent  to  which  you  establish  the  scientific  context  for  the  work,  state  a   clear  and  focused  research  question  and  use  concepts  and  techniques  appropriate  to  the  Diploma   Programme  level.  Where  appropriate,  this  criterion  also  assesses  awareness  of  safety,   environmental,  and  ethical  considerations.        

 

Mark

 

0

 

1–2

Descriptor The student’s report does not reach a standard described by the descriptors below.

 

The topic of the investigation is identified and a research question of some relevance is stated but it is not focused. The background information provided for the investigation is superficial or of limited relevance and does not aid the understanding of the context of the investigation.

 

The methodology of the investigation is only appropriate to address the research question to a very limited extent since it takes into consideration few of the significant factors that may influence the relevance, reliability and sufficiency of the collected data.  

The report shows evidence of limited awareness of the significant safety, ethical or environmental issues that are relevant to the methodology of the investigation*.

 

The topic of the investigation is identified and a relevant but not fully focused research question is described.

3–4  

The background information provided for the investigation is mainly appropriate and relevant and aids the understanding of the context of the investigation.  

The methodology of the investigation is mainly appropriate to address the research question but has limitations since it takes into consideration only some of the significant factors that may influence the relevance, reliability and sufficiency of the collected data.  

The report shows evidence of some awareness of the significant safety, ethical or environmental issues that are relevant to the methodology of the investigation.*

 

5–6

The topic of the investigation is identified and a relevant and fully focused research question is clearly described.  

The background information provided for the investigation is entirely appropriate and relevant and enhances the understanding of the context of the investigation.  

The methodology of the investigation is highly appropriate to address the research question because it takes into consideration all, or nearly all, of the significant factors that may influence the relevance, reliability and sufficiency of the collected data.  

The report shows evidence of full awareness of the significant safety, ethical or environmental issues that are relevant to the methodology of the investigation.*

                 

     

 

                                                             

5  

Example  Format  for  Exploration  Section  

 

Title:  ‘  The  effect  changing  x  has  on  y’  or  ‘How  x  affects  y’  

 

Background  Information:  including  any  equations  and  reactions  or  other  scientific   information  necessary  to  understand  the  purpose  of  the  investigation.    Explain  how  your   investigation  links  to  the  curriculum.  Include  a  justification  for  your  design,  relating  to  (as   much  possible-­‐  do  not  make  it  up)  personal  significance,  interest  and  curiosity.  This  section   should  be  in  your  own  words.    Use  citations  where  appropriate.  Note:  This  section  is  not   intended  to  include  any  discussion  of  your  conclusion  or  possible  results.  

 

Research  Question  (included  in  the  introduction):  must  refer  to  both  the  independent  and   the  dependent  variables  

 

Variables:   • State  independent  variable  (what  you  decided  to  change/investigate)   • State  the  range  that  you  will  be  investigating  (should  have  a  range  of  at  least  5  levels)   • Justify  why  you  chose  this  independent  variable  and  this  specific  range   • Explain  why  this  is  appropriate  and  relevant  relative  to  the  research  question  of  the  goal  of   the  investigation     • State  dependent  variable  (what  you  are  measuring/gathering  data  on)   • Clarify  the  technique  that  you  will  be  using  to  collect  this  data   • Explain  why  this  is  an  appropriate  technique  (if  applicable)     • State  all  relevant  control  variables  (the  other  factors  that  my  affect  your  results)   • Describe  what  your  significant  control  variables  are   • Explain  how  you  will  keep  each  constant  in  the  experiment  and/or  how  you  will  monitor  each   variable   • This  control  should  be  apparent  and  referenced  in  the  procedure!     Materials:     • Provide  a  list  of  all  equipment/materials  needed   • Select  appropriate  equipment  (meaning,  do  not  use  a  beaker  to  measure  volume)   • List  the  quantity  you  require  of  each  material  (you  should  detail  trial  runs  to  calculate  how   much  you  would  need  in  order  to  perform  all  of  your  trials)   • List  any  sizes  of  equipment,  as  appropriate  (e.g.  50cm3  burette)   • List  uncertainties  with  equipment  (ex:  electronic  mass  balance  ±  0.001g)  –  see  separate   handling  errors  and  uncertainties  document.     • Include  a  diagram  where  appropriate  of  your  setup  

 

Ethical,  Safety,  or  Environmental  Issues:   • Go  through  your  materials  list  and  acknowledge  anything  that  has  different  ethical,  safety,  or   environmental  considerations  (the  MSDS  sheet  will  have  safety  data  for  chemicals)   • Think  about  the  manipulation  and  disposal  of  your  different  materials     • If  there  are  no  ethical/safety/environmental  considerations,  you  should  at  least   acknowledge  and  maybe  justify  this.     6      

Method:   • State  the  need  for  a  trial  run   • Your  trial  runs  should  be  acknowledged  and  the  information  you  obtain  from  there  should  be   documented  in  your  report  (ex:  if  you  learned  during  your  trial  runs  that  you  needed  to   change  the  range  of  your  independent  variable/concentration  of  one  of  the  chemicals,  this   should  be  reflected  in  your  report  –  it  looks  good)   • Include  a  step-­‐by-­‐step  procedure   • Make  sure  that  when  you  reference  previous  steps,  you  are  careful  to  reference  the  correct   ones   • Mention  how  you  are  controlling  variables  (do  not  directly  repeat  what  you  wrote  earlier  in   the  variables  section,  but  acknowledge  where  you  are  addressing  controls)   • Carry  out  the  appropriate  number  of  trials  (at  least  3)  over  an  appropriate  range  of  the   independent  variable  of  you  are  investigating  a  trend  (5  is  good)  and  justify  your  choice.    

 

Any  diagrams,  tables  and  graphs  in  this  section  should  be  numbered  and  titled  (e.g.  Table  1a  or   Graph  2)       TOP  TIP:    As  you  carry  out  your  investigation,  make  notes  beside  the  steps  in  your  method  where   assumptions  have  been  made/errors  could  be  made/controls  have  been  put  in  place  as  best  as   possible  but  do  not  eliminate  a  possible  issue/observations  made  at  crucial  points.  These  notes  will   help  you  in  your  qualitative  data  and  your  evaluation.                                                       7      

Analysis    

 

This  criterion  assesses  the  extent  to  which  you  report  provides  evidence  that  you  have  selected,   recorded,  processed  and  interpreted  the  data  in  ways  that  are  relevant  to  the  research  question   and  can  support  a  conclusion.   Mark

Descriptor

0

The student’s report does not reach a standard described by the descriptors below. The report includes insufficient relevant raw data to support a valid conclusion to the research question.

1–2  

Some basic data processing is carried out but is either too inaccurate or too insufficient to lead to a valid conclusion.  

The report shows evidence of little consideration of the impact of measurement uncertainty on the analysis.  

The processed data is incorrectly or insufficiently interpreted so that the conclusion is invalid or very incomplete. The report includes relevant but incomplete quantitative and qualitative raw data that could support a simple or partially valid conclusion to the research question.

3–4  

Appropriate and sufficient data processing is carried out that could lead to a broadly valid conclusion but there are significant inaccuracies and inconsistencies in the processing.  

The report shows evidence of some consideration of the impact of measurement uncertainty on the analysis.  

The processed data is interpreted so that a broadly valid but incomplete or limited conclusion to the research question can be deduced. 5–6

The report includes sufficient relevant quantitative and qualitative raw data that could support a detailed and valid conclusion to the research question.  

Appropriate and sufficient data processing is carried out with the accuracy required to enable a conclusion to the research question to be drawn that is fully consistent with the experimental data.  

The report shows evidence of full and appropriate consideration of the impact of measurement uncertainty on the analysis.  

The processed data is correctly interpreted so that a completely valid and detailed conclusion to the research question can be deduced.

      •          

You  ensure  you  are  collecting  sufficient  quantitative  data  by  deciding  on  what  is  sufficient  in   your  method  (e.g.  5  different  runs  of  the  variable,  3  repeats  etc    -­‐  whatever  is  needed  to  allow   you  to  generate  a  conclusion  to  your  research  question)  

     

8  

Raw  data     • Record  qualitative  and  quantitative  data   • Use  data  tables.  They  should  be  numbered  if  you  have  more  than  one,  for  easy  reference   • Data  tables  should  have  descriptive  titles  NOT  “Data  Processing”  or  “Raw  Data”  or  “Data   Collection”.  INSTEAD,  something  like  ‘Masses  of  different  substances’,  ‘Qualitative   observations  during  the  reaction  between  Magnesium  and  Oxygen.”   • Columns  need  to  have  descriptive  headings  -­‐  NOT  “Trial  1”,  INSTEAD,  “Mass  of  Mg,  Trial  1”   • Column  headings  need  to  have  units   • DO  NOT  put  the  units  beside  the  measurements  (e.g.  do  not  write  1.00g,  2.25g  each  time)   • Column  headings  need  to  have  uncertainties  (see  uncertainties  document)   • DO  NOT  put  uncertainties  beside  the  measurements  (see  above)   • You  should  only  use  another  column  for  uncertainties  if  they  are  different  for  the  different   values  in  your  column   • At  the  bottom  of  each  data  table  it  is  helpful  to  explain  how  each  of  your  uncertainty  values   were  chosen   • Your  measurements  need  to  be  recorded  with  the  correct  precision.  If  your  temperature   probe  shows  20.0  oC,  you  record  EXACTLY  that,  NOT  20  oC   • Check  that  the  precision  of  your  measurements  matches  the  precision  of  your  uncertainty.   E.g  2.34  with  an  uncertainty  of  ±0.01  match  because  the  uncertain  digit  is  the  last  one  of   your  measurement,  recording  2.3  with  an  uncertainty  of  ±0.01  is  incorrect.   EXAMPLE  DATA  COLLECTION     •  

Table  1:  Table  showing  the  masses  of  different  substances  in  the  reaction  between   Magnesium  and  Oxygen.   Measurement  

Mass  ±  0.001  g  

Mass  of  empty  crucible   22.832   Initial  Mass  of  Reaction  Setup  (Crucible   22.930   +  Lid  +  Magnesium)   Final  Mass  of  Reaction  Setup   (Magnesium  Oxide  +  other  products  +   Crucible  +  Lid)  

22.993  

Magnesium  

0.098    

Calculated  Mass  of  Oxygen  added  to   form  MgO  

0.063  

                 

9  

Qualitative  Observations  –  these  are  often  crucial  to  your  evaluation     • The  Magnesium  was  a  silvery  solid  metal  ribbon.   • The  mass  was  weighed  by  placing  the  Magnesium  inside  the  Crucible,  placing  the  lid  atop  it  and   then  setting  this  inside  an  analytical  balance,  closing  the  doors  and  obtaining  the  mass  reading.   • The  mixture  was  heated  repeatedly.  Upon  the  first  gentle  heating,  steam  escaped  from  the   crucible  when  the  lid  was  lifted  for  the  first  time.  The  Magnesium  had  turned  into  a  white  solid   which  continued  to  glow  orange  periodically  for  3  minutes  of  strong  heating.     • Thereafter  the  white  external  surface  of  the  product  developed  black  cracks  and  also  seemed  to   have  adhered  to  the  interior  surface  of  the  crucible.  The  product  was  still  in  the  shape  of  the   original  magnesium  pieces.   • Distilled  water  was  added  to  the  crucible  to  cover  the  magnesium  and  the  crucible  was  heated  to   evaporate  the  water.  During  this  heating  the  mixture  bubbled  and  small  black  specks  were  seen   flying  out  when  the  crucible  was  heated  for  too  long  due  to  the  position  of  the  Bunsen  burner   remaining  unchanged.   • After  adding  and  boiling  off  water,  the  mass  reading  was  taken  and  this  was  repeated  twice  after   which  the  mass  readings  became  constant.  Thereafter  the  final  mass  of  the  reaction  setup  was   recorded.  

 

Data  Processing:       Calculations:   • You  need  to  show  calculations  for  each  step  of  your  data  processing.  DO  NOT  skip  any  step.     • All  of  your  calculations  need  to  first  include  a  descriptive  label.  Do  not  just  put  in  numbers   • NOT:   𝑥 + 𝑦 + 𝑧 ÷ 3   !"#!.!"#$%  !!!"#$.!"#$%  !!!"#$.!"#$%  !

•

INSTEAD:  𝐴𝑣𝑒𝑟𝑎𝑔𝑒  𝑡𝑒𝑚𝑝𝑒𝑟𝑎𝑡𝑢𝑟𝑒 =  

•

You  only  need  to  show  one  sample  calculation,  generally  under  the  table  that  contains  the   data  obtained  using  the  calculation.  Use  data  from  one  trial  to  actually  perform  each  calculation   step   Your  calculation  results  must  include  units   Your  calculation  results  must  be  rounded  to  the  correct  number  of  significant  figures  according   to  your  recorded  raw  data:   Adding  or  subtracting  numbers:  round  to  smallest  number  of  decimal  places   Multiplying  or  dividing  numbers:  round  to  smallest  number  of  sig.  figs.     After  each  calculation  step,  provide  a  calculation  label  for  the  way  in  which  you  propagate   uncertainties  for  that  step.     You  only  need  to  show  one  sample  calculation  for  your  uncertainty  propagation  (see   uncertainties  document).     Convert  %  uncertainty  to  absolute  uncertainty  for  your  final  answer     Your  final  uncertainty  should  be  reported  to  1  significant  figure.     If  needed,  you  should  round  your  answer  to  match  the  precision  of  your  uncertainty.  

• • • • • • • • •

•

!

 

Don’t  use  1.3  E10-­‐-­‐-­‐3  from  your  calculator!  Use  the  proper  subscript  (lower)  and   superscript  (upper)  forms,  i.e.  3x10-­‐3   is  good.  C4H8,  H2O  etc  are  bad!!!  

     

     

10  

Data  Processing  Tables:     • All  of  your  calculations  need  to  be  organized  in  one  or  more  Data  Processing  Tables.  These  tables   should  still  follow  the  requirements  for  putting  together  a  table,  as  described  in  the  Data   Collection  Section.     EXAMPLE  DATA  PROCESSING  TABLES     Table  2:  Table  containing  the  processed  values  for  calculating  the  empirical  formula  of  the   Magnesium  and  Oxygen  compound       Measurement   Number  of  Moles  of  Magnesium  (from  mass  of  magnesium  initially  measured)  ±   0.00004  mol   Number  of  Moles  of  Oxygen  (from  mass  of  oxygen  via  mass  difference  method)  ±  3%   Calculated  Empirical  Formula  of  MgO   Theoretical  formula  of  MgO  (from  balanced  equation)     Samples  of  calculations  carried  out  can  go  here.     Table  3:  Table  containing  the  values  for  calculating  the  %  yield  of  MgO     Measurement   Actual  Mass  of  MgO  obtained  ±  0.003  g   Theoretical  Mass  of  MgO  that  should  have  been  obtained   Percent  Yield  of  MgO  (%)  ±  2%   Percent  Error  in  Mass  of  MgO  (%)   Percent  Error  in  Mass  of  Magnesium  (%)   Percent  Error  in  Mass  of  Oxygen  (%)    

Value   0.00403     0.0039     MgO   MgO  

Value   0.161g   0.16g   99   0.9   -­‐0.9   -­‐1  

Samples  of  calculations  carried  out  can  go  here.     Graphs:     • Graphs  should  have  descriptive  titles   • The  graph  axes  need  to  be  labeled  with  units  and  uncertainties   • You  graph  should  be  scaled  appropriately  so  that  the  data  points  fit  the  graph  area  well.     • A  best-­‐fit  line  should  be  added   • Below  your  graph,  you  should  comment  on  the  ways  in  which  your  errors  seemed  to  have   impacted  your  trend  line   • Ex:  if  you  were  expecting  a  linear  relationship,  but  your  data  points  result  in  more  of  a  curve,   mention  this  and  briefly  state  what  you  will  be  considering  in  your  evaluation.            

     

11  

Example  Graph  

                                             

12  

Evaluation     This  criterion  assesses  the  extent  to  which  your  report  provides  evidence  of  evaluation  of  the   investigation  and  the  results  with  regard  to  the  research  question  and  the  accepted  scientific   context.     Mark

Descriptor

0

The student’s report does not reach a standard described by the descriptors below. A conclusion is outlined which is not relevant to the research question or is not supported by the data presented.

1–2  

 

The conclusion makes superficial comparison to the accepted scientific context. Strengths and weaknesses of the investigation, such as limitations of the data and sources of error, are outlined but are restricted to an account of the practical or procedural issues faced.

 

The student has outlined very few realistic and relevant suggestions for the improvement and extension of the investigation. A conclusion is described which is relevant to the research question and supported by the data presented.

3–4  

A conclusion is described which makes some relevant comparison to the accepted scientific context.  

Strengths and weaknesses of the investigation, such as limitations of the data and sources of error, are described and provide evidence of some awareness of the methodological issues* involved in establishing the conclusion.  

The student has described some realistic and relevant suggestions for the improvement and extension of the investigation. 5–6

A detailed conclusion is described and justified which is entirely relevant to the research question and fully supported by the data presented.  

A conclusion is correctly described and justified through relevant comparison to the accepted scientific context.  

Strengths and weaknesses of the investigation, such as limitations of the data and sources of error, are discussed and provide evidence of a clear understanding of the methodological issues* involved in establishing the conclusion.  

The student has discussed realistic and relevant suggestions for the improvement and extension of the investigation.

  •

• •

Conclusion:   Answer  the  research  question/state  the  trend/state  the  relationship  or  information  that  you   obtained  from  your  experiment.  This  is  directly  related  to  the  purpose  of  the  lab  –  what  did   you  find  out?   Instead  of  just  stating  a  relationship,  provide  data  from  your  lab  to  support  your  conclusion.     For  example,  state  the  slope  of  your  graph  to  explain  what  the  relationship  is  between  two   variables  you  were  investigating        

13  

• • •

• • • • •

You  can  also  relate  your  results  back  to  the  hypothesis  that  you  originally  had  and  discuss  the   degree  to  which  your  data  support  or  refute  your  hypothesis   Compare  your  results  to  scientific  theory  –  explain  what  you  were  expecting  to  find,  based  on   theory  and  why  it  was  supposed  to  be  so.     When  measuring  an  already  known  and  accepted  value  of  a  physical  quantity,  compare  the   experimental  value  with  the  textbook  or  literature  value.  Be  sure  to  reference  the  literature   used.   If  applicable,  state  the  theoretical  or  expected  value  and  compare  your  result  to  it  using  the  %   Error  calculation  results  (see  uncertainties  document).   You  must  take  into  account  any  systematic  or  random  errors  and  uncertainties.   A  percentage  error  should  be  compared  with  the  total  estimated  random  error  as  derived  from   the  propagation  of  uncertainties.   Discuss  whether  systematic  error  or  further  random  errors  were  encountered  (for  more  detail   on  types  of  error  see  the  handling  errors  and  uncertainties  document).   Include  comparisons  of  different  graphs  or  descriptions  of  trends  shown  in  graphs.  

When  writing  a  conclusion  consider  the  following:   • • • • • •

•

• •

•

Consider  how  large  the  errors  or  uncertainties  in  your  results  are,  how  confident  are  you  in  the   results?  Are  they  fairly  conclusive,  or  are  other  interpretations/results  possible?   Was  your  value  too  low?  What  errors  contributed  to  making  it  low?  (just  a  list  at  this  point)   Was  your  value  too  high?  What  errors  contributed  to  making  it  too  high?   Which  error,  of  those  listed,  was  the  most  significant?   Are  your  results  reliable,  given  the  errors  listed?  Justify  this.   Make  sure  to  use  appropriate  and  descriptive  scientific  language.     Evaluation:     Discuss  the  strengths  of  the  investigation.  These  could  be  related  to     • Procedure   • Equipment   • Number  of  trials   • Control  of  variables   • Range  of  independent  variables,  etc.     Do  not  just  state  strengths,  but  describe  and  explain  them.  Also  state  how  these  strengths   improved  your  results.     Discuss  the  errors  or  assumptions  of  the  investigation.  One  separate  paragraph  for  each:     • Describe  error   • How  did  it  impact  the  data?  Did  it  make  the  recorded  values  larger  or  smaller  and   therefore  what  effect  would  it  have  on  the  final  result?  DO  NOT  just  state  that  it  may   have  affected  the  results  –  specify  how  it  affected  the  results  and  the  significance  of   it.   • How  could  it  be  improved,  realistically,  in  our  lab?   • Describe  improvement   Possible  errors/issues  to  improve  should  be  related  to:     14      

• •

•

• Procedure   • Equipment   • Number  of  trials   • Control  of  variables   • Range  of  independent  variables,  etc.     Comment  on  the  reliability  (precision)  and  validity  (accuracy)  of  your  results.     State  and  describe  a  possible  extension  to  the  investigation.     • This  cannot  just  be  a  random  idea  that  you  don’t  know  how  it  could  work  or  is  not   feasible.     • You  actually  have  to  provide  general  description  of  what  you  would  do  during  that   extension  investigation.     • Explain  the  reasons  why  it  would  be  a  good  extension/why  you  would  want  to  carry  it   out/what  information  it  would  give  you  (think  of  any  questions  that  arose  during  the   investigation,  or  how  the  impact  of  any  possible  assumptions  or  errors  could  be   investigated  further.     Don’t  forget  a  bibliography  for  all  outside  information,  especially  the  information  related  to   your  scientific  theory  explanations.      

Evaluation  example  –  one  section  only.  Yours  will  have  many  paragraphs  like  this  for  each  error.   One  assumption  made  in  reacting  the  magnesium  ribbon  in  the  crucible  is  that  only   magnesium  oxide  is  formed.  When  the  mass  of  the  crucible  is  taken  at  the  end  of  the   experiment,  it  is  assumed  that  all  of  the  extra  mass  is  attributed  to  the  reaction  of  oxygen   with  magnesium  to  form  MgO.  However,  at  such  high  temperatures  it  is  possible  that   some  magnesium  reacted  with  the  nitrogen  in  the  air  to  form  magnesium  nitride.  This   means  that  the  measured  mass  is  not  only  MgO  but  also  in  fact  some  magnesium  nitride.   This  would  result  in  our  recorded  mass  of  oxygen  being  higher  than  the  actual  true  mass   present  in  the  crucible  and  increasing  the  ratio  of  oxygen  in  our  empirical  formula   beyond  what  is  actually  there.  In  order  to  reduce  and  possibly  eliminate  this  error,  we   could  improve  the  method  by  adding  the  extra  step  of  adding  water  to  the  crucible   following  heating.  This  can  then  be  evaporated  over  the  bunsen  burner  in  order  to   ensure  the  Magnesium  Nitride  that  was  formed  decomposes  into  Magnesium  Hydroxide   and  ammonia.  The  magnesium  hydroxide  forms  Magnesium  Oxide  upon  further  heating.   This  would  ensure  that  the  mass  of  the  product  measured  was  of  the  desired  compound   only,  i.e.  Magnesium  Oxide.     Another  error…..  and  so  on.                

15  

Communication    

This  criterion  assesses  whether  the  investigation  is  presented  and  reported  in  a  way  that  supports   effective  communication  of  the  focus,  process  and  outcomes.    

Mark

Descriptor

0

The student’s report does not reach a standard described by the descriptors below. The presentation of the investigation is unclear, making it difficult to understand the focus, process and outcomes.

1–2  

The report is not well structured and is unclear: the necessary information on focus, process and outcomes is missing or is presented in an incoherent or disorganized way.  

The understanding of the focus, process and outcomes of the investigation is obscured by the presence of inappropriate or irrelevant information.  

There are many errors in the use of subject specific terminology and conventions*. 3–4

The presentation of the investigation is clear. Any errors do not hamper understanding of the focus, process and outcomes.  

The report is well structured and clear: the necessary information on focus, process and outcomes is present and presented in a coherent way.  

The report is relevant and concise thereby facilitating a ready understanding of the focus, process and outcomes of the investigation.  

The use of subject specific terminology and conventions is appropriate and correct. Any errors do not hamper understanding.

   

*For  example,  incorrect/missing  labelling  of  graphs,  tables,  images;  uses  of  units,  decimal   places  

 

• • • • • •

  Organize  your  sections  clearly,  with  labels   Structure  your  report  in  a  logical  way   Organize  your  paragraph  to  include  one  main  idea/topic  per  paragraph.  Do  not  just  jumble  all   kinds  of  information  into  one  huge  paragraph.     Use  correct  scientific  language.   Be  specific  and  unambiguous.  Shorter  sentences  are  often  clearer.     Proof-­‐read  your  work  for  any  errors.        

By  using  the  example  format  structures  given  in  this   guide  you  will  be  able  to  write  a  well-­‐-­‐-­‐structured  and   clear  report.          

16