administration student task rubric student work technical quality

Grades 9-12 Performance Task
Contributed by: New York State Education Department (NYSED)
Developed through University of Buffalo and NORC (1991)

Task-Specific Scoring Criteria for Biology Task #4: Diffusion


1. Statement of hypothesis  
- Effect linked to variable As concentration and time increase, distance of diffusion also increases; cubes.
- Directionality of effect Distance of diffusion increases.
- Expected effect/change Distance of KMnO4 varies with concentration and/or time.
- Independent variable Time, concentration
- Dependent variable Distance of KMnO4 that travels into the cubes.
2. Procedures for investigation  
- Detailed procedure/experimentally feasible Plan includes measurement of diffusion distances from a combination of concentrations (1%, 5%, 10%) and time (e.g. 5m, 10m, 15m, 20m) that the cubes stay in the solution.
- Sequence to plan At least two times and two concentrations are included in plan.
- General strategy Plan includes varying time and concentration.
- Safety procedures Care not to spill KMnO4; wearing apron and goggles; care in using scalpel might be suggested.
- Use of equipment/diagram Appropriate equipment and materials are suggested.
3. Plan for recording and organizing observations/data  
- Space for manipulation of data or qualitative description * (Space for qualitative description might be included).
- Matched to plan Plan includes observations and data which are consistent with the plan.
- Organized sequentially Organized so that recording follows data as generated.
- Labelled fully (units included) All columns and rows are identified, correct units of measurement are used.
- Variables identified Time, concentration, and diffusion distance are clearly indicated.


* These elements were not scored in this task; a "holistic" scoring approach was utilized so that the other four elements had a total value of 5 points.


4. Quality of observations/data  
- Consistent data Distance increases with increasing concentration and time.@
- Accurate measurements/observations Accurate measurement of the distance reached by the diffusing KMnO4 in every five minutes.@
- Completed data table All data entered in the table.
- Correct units Distances are labelled as mm.
-Qualitative description * (Variability of distance of diffusion within a single cube might be mentioned
5. Graph  
- Curve is appropriate to data trend Curve drawn best fits data points.
- Points plotted accurately Plotted points are accurate.
- Appropriate scale Values of scales are appropriate to ranges of data.
- Axes labelled with variables Time in minutes; concentration in percentages; distance in mm.
- Variables placed on correct axes Dependent variable, distance of diffusion is the y axis; independent variables, time and concentration (on the x axis) can be placed on separate graphs OR combined as three separate plots of concentration within one graph with time as the x axis
6. Calculations Not required for this task
- Calculated correctly  
- Substituted correctly into relationship  
- Relationship stated or implied  
- Units used correctly  
- Use all data available  
7. Conclusion  
- Consistent with scientific principle As concentration and time increase, distance of diffusion also increases.
- Sources of error * (Measurement of distance may be hard to measure accurately.)
- Consistent with data Consistent with student's experimental results. 1
- Relationship among variables stated Distance of diffusion is related to concentration of KMnO4 and/or time. 1
- Variables stated in conclusion Distance of diffusion, concentration of KMnO4 solution, time.



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